REVIEW QUESTIONS

1. What is the sample for compressive strength determination of a structural concrete?Answer: concrete cylinder sample

2. What is the test to determine the consistency of concrete?Answer: Slump test

3. What is the length required for RSB

sample for quality test?Answer: 1.0 m/10,000kg/size/shipment

4. How many samples should be taken for every 75 cu.m fresh concrete?Answer: 1 set consist of 3-pcs sample

5. What is the required size of test specimen for G.I. sheets?Answer: 3 pcs-60mm x 60mm in 1 sht/100shts

6. What kind of paint that has a reflectance or beads?Answer: Reflectorized paint

7. What is that construction material that has a property of being a dark brown to black cementitious material in which the predominating substance is bitumen?Answer: asphalt

8. For how long or how many hours shall a bituminous prime coat be left undisturbed?Answer: 24 hours

9. What is the rate of application of bituminous tack coat?Answer: 0.2 to 0.7 L/sq. m

10. What is the penetration grade of blown asphalt?Answer: 0 to 30 penetration grade

11. What kind of sample is taken for flexural test?Answer: concrete beam sample

12. What are the tests needed for the 2.650 cu.m Item 201 (Aggregate Base Course)?

Answer: CBR, abrasion, GPCD

13. How many grading tests are required for a 3,200 cu.m selected borrow topping (Item 104)?Answer: 3 grading tests

14. As a materials Engineer, what will you recommend if you find out that the materials to be used as Item 200 if finer than the required materials?Answer: blend Item 200 with coarser materials

15. What is the standard specification for LL

and PI of Item 201?Answer: maximum of 25% and maximum of 6% respectively

16. What is the CBR requirement for Item

201?Answer: 80% maximum

17. What asphalt is used for sealing weaken

plane joint of concrete pavement?Answer: Blown Asphalt

18. What is Item 311 of the DPWH Specification (Blue Book)?Answer: Portland Cement

Concrete Pavement

19. What is the machine used for abrasion

test?Answer: Los Angeles Abrasion Machine

20. How to determine the degree of compaction of Items 104, 200, &

201?Answer: by Field Density Test

21. What is the formula in obtaining the

value of PI?Answer: Liquid Limit minus

Plastic Limit

22. What are the other terms for sieve analysis?Answer: Grading Test, Particle

Size Distribution Test, Mechanical Analysis

23. What is the degree of compaction of the soil if the wet density is 2,200 kg/m3, with an actual moisture content of 10.2% and a maximum dry density of 1,960 kg/m3?Answer: 101.86% dry den =

wet den/mc+1 deg c =dd/mdd

24. How many concrete cores shall be taken

for one (1) kilometer concrete pavement?Answer: 5 holes/km/lane

25. What is the moisture content of the soil having an original weight of 162.5 grams and an oven – dried weight of 138.2 grams?

162.5-138.2/138.2Answer: 17.58%

26. If the group index of a soil is high, what indication does it mean?Answer: the soil is clayey

27. As a Materials Engineer, how can you determine that the sample placed in the oven is already oven – dried?Answer: if the sample reaches its constant weight

28. In oven drying a sample for test, what temperature shall be maintained?Answer: 110 ± 5°C

29. Why is it that cooling an oven dried sample before weighing is advisable?Answer: because it can affect its weight

30. What is the difference between hygroscopic moisture content from natural moisture content?Answer: HYGROSCOPIC MOISTURE CONTENT is the moisture content of an air – dried sample while NATURAL MOISTURE CONTENT is the moisture content of the original sample from the field.

31. For how many bags of cement does a 10 kgs sample arepresents?Answer: 2000 bags

32. For 15, 000 kgs RSB, how many samples shall be submitted for Quality Test?Answer: 2 pcs – 1 m sample

33. An admixture is being introduced to the fresh concrete mixture for heavily reinforced concrete structure using a pump Crete to pump out the fresh concrete mix, what admixture should it be?Answer: Super plasticizer

34. What is the use of blown asphalt? Answer: as joint filler and

water proofing

35. What asphalt is commonly known as hot asphalt or penetration grade asphalt?Answer: Asphalt Cement

36. How many days does the sample for Immersion – Compression Test be soaked in water?Answer: 4 days @ 50°C

37. If ductility test is for asphalt, _____ is for cement?Answer: Magnesium Oxide, Insoluble Residue, Loss on Ignition

38. Paint is composed of _____Answer: 35% vehicle, 50% pigment, 15% beads

39. What is the size of tamping rod used in tamping concrete sample?Answer: 16 mm Ø and 610 mm long with hemispherical tip

40. What is the temperature to be maintained when curing sample after its initial curing?Answer: 23°C ± 1.7°C

41. Concrete cylinders are cured and

ready for test. Temperature between 63°F to 85°F are permitted for a period not to exceed _____ hours immediately prior to test if free moisture is maintained on the surface of the specimen at all times.Answer: three (3)

42. The molds of specimen not to be transported shall be removed after initial curing of _____ hours and

should be cured to the standard curing temperature of 73.4 °F ± 3°FAnswer: Twenty – four (24)

43. High plasticity index means _____ of a soil?Answer: high degree of compressibility

44. Sample to be used for liquid limit and plastic limit tests should pass to what sieve?Answer: No. 40 (0.425 mm)

45. What compaction rammer shall used if the specs given for Moisture – Density Relation Test (MDR) is T – 180?Answer: 4.54 kg with 457 mm drop

46. A bean mold measuring 6” x 6” x 20 is to be used for sampling concrete, how many blows/tamps per layer shall be applied?Answer: 60 blows/layer if 21in=63blows

47. If asphalt mix having a weight of 3,020g and an aggregate weighing 2,865.98g, what is the % asphalt by weight of mix?Answer: 5.10%

48. What is the material used for Bituminous Prime Coat?Answer: Cut – back asphalt

49. In Item 303, application of cover aggregates shall be evenly spread over the surface at the rate of approximately _____?Answer: 0.004 to 0.007 m3/m2

50. Applying the tolerance of 0.4% for asphalt content to your answer in prob. 47, what is the acceptable range of asphalt content?Answer: 4.7% to 5.5%

51. An embankment having a PI of 30%, LL of 40% and GI of 0, what is the degree of compaction for this kind of soil?Answer: 95% degree of compaction

52. The minimum cement factor for concrete Class “A” is 9 bags/cu.m, how about for concrete Class “B”?Answer: 8 bags/cu.m

53. Quality control testing in a DPWH project is the responsibility of the_____?Answer: Contractor

54. As Materials Engineer, when is the right time to start sampling and testing aggregates?Answer: Once the source is identified

55. The minimum compressive strength for concrete Class “P” is 5,000 psi, what is the minimum compressive strength for concrete Class “C”?Answer: 3,000 psi

56. The volume of concrete mixer per batch shall not exceed the mixer’s nominal capacity in cu.m as shown on the manufacturer’s standard plate on the mixer, except that an overload up to _____ percent above the mixer’s nominal capacity may be permitted provided concrete test data for strength, segregation, and uniform consistency are satisfactory, and provided that no spillage of concrete takes place.Answer: Ten (10)

57. Where do we take additional cores when the measurement of any core taken from pavement is deficient in thickness by more than 25 mm?Answer: at no less than 5 meter intervals parallel to the centerline in each direction from the affected location

58. Under what climatic condition do we use lower penetration grade or hard asphalt?Answer: hot climate (cold climate – higher penetration grade or soft asphalt)

59. What is the basis for the acceptance or rejection of any construction material?Answer: Materials test results/reports

60. Penetration test is for asphalt: cement is to _____?Answer: consistency

61. Slump test is a very important test in fresh concrete to determine _____?Answer: consistency of concrete

62. How many samples should be taken for an asphalt mix for each full day’s operation?Answer: at least one but not to exceed three samples

63. The thickness of asphalt core using a caliper is based on how many measurements?Answer: four (4)

64. The thickness of concrete core using a caliper is based on how many measurements?Answer: nine (9)

65. Failed samples do not necessarily mean that the structure it represents is defective, why?Answer: may be the sampling is incorrect

66. The specification calls for a 1: 2:4 concrete mix. In a one bagger mixer, which of the following amount of water is most likely required for the mix?Answer: 20 liters

67. The spot test on asphalt is used to determine ______.Answer: overheating during the process of manufacture

68. How many samples shall be submitted for test if 315 pails of flat wall enamel paint are to be used in the project?Answer: four (4) pails

69. Aggregate Sub – base course has a volume of 5, 000 cu.m and to be laid in a 15cm compacted depth. How many samples shall be submitted for CBR test and for sieve analysis?Answer: 2 samples for CBR and 17 samples for sieve analysis

70. How many samples shall be submitted for quality test if 60 tons of Bituminous Prime Coat is to be used in the project?Answer: Two (2) samples

71. How many compaction tests shall be conducted for Item 201 having a volume of 8,250 cu.m?Answer: Six (6) compaction tests

72. What composed of Materials Quality Control Monthly Reports?Answer: Summary of field tests and status of test

73. What is the required mixing of mortar for Item 505 (Stone Masonry)?Answer: 1 part cement and 2 parts sand by volume with sufficient water

74. What is the required mixing of mortar for Item 500 (Pipe Culverts and Storm Drains)?Answer: 1 part cement and 2 parts sand by volume with sufficient water

75. Before the project starts, the materials Engineer or the technician must have a program on how many samples for each item of work should be tested based on the minimum testing requirements. What program or report is this?Answer: Quality Control Program

76. If sample splitter is not available for use in reducing samples for test, what is the alternative way of reducing sample for testing size?Answer: apply quartering method and get two opposite sides as sample

77. The road will not be opened to traffic until test specimens molded and cured have attained the minimum strength requirements. If such tests are not conducted prior to the specified age the pavement shall not be operated to traffic until _____ days after the concrete was placed.Answer: Fourteen (14)

78. As the work progresses, the Materials Engineer should know how many sample has been submitted and tested and how many samples are to be submitted, in other words the ME must refer to

what report so that he/she may be updated on the balance and on file quality test of the construction materials being used in the project?Answer: Status of Test

79. It is the minimum moisture content at which the soil can be molded without breaking or crumbling up to 1/8” (3.2 mm).Answer: Plastic Limit

80. The _____ is expressed as the moisture content corresponding to 25 blows.Answer: Liquid Limit

81. The concrete has been tested for consistency by the use of a slump cone with base and tamping rod. After the test, the height of concrete measured is 178 mm. what is the slump of the concrete?Answer: 127 mm

82. What is the rate of revolution per minute of an abrasion Machine used for testing the mass percent of wear?Answer: 30 – 33 rpm

83. If the design of concrete mix has the following corrected batch weights: cement = 40 kgs, fine aggregates = 65 kgs, coarse aggregate = 115 kgs, and water = 15 liters. What is your actual batch weights for 1 cu.m Class “A” concrete?Answer: 360 bags of cement; 585 kgs of fine aggregates; 1035 kgs coarse aggregates; 130 liters water

84. After the soil has been tested in an Abrasion Machine, the mass % of wear computed is equal to 21%. If this material is for Item 201, does it pass the DPWH specs?Answer: Yes, because the specs is 50% maximum

85. Quality Control Assurance Report should be submitted every _____?Answer: week

86. One of the duties of Materials Engineer is to see to it that all the construction materials be tested:

Answer: before it is incorporated into work

87. What is the maximum depth or roadway embankment per horizontal layer in loose measurement?Answer: 200 mm loose measurement

88. Why is it that 6 samples are needed for quality test of concrete masonry?Answer: 3 samples for compressive strength and 3 samples for absorption

89. Sample submitted for test should have a tag bearing the name of the project, the quantity represented, kind of sample, original source, who sampled and who submitted it, the date sampled and date submitted and etc. What is the common name of that tag for you as Materials Engineer?Answer: Sample Card

90. If course aggregate like embankment is to be placed in layers, how many layers should a 40 cm thick Aggregate Base Course is placed?Answer: Three (3)

91. The ME should always be alert of his schedule with regards to the number of days of a quality test that takes place. Since not all construction materials can be tested just for a day or even a week so, what is the lead time should he consider for a quality test of a cement sample?Answer: One (1) month

92. CBR Sample for test has been compacted but it should be soaked for how many days before testing?Answer: Four (4)

93. If sieve analysis and plasticity test are used for Soil Classification, what test that its result be used in field density test?Answer: Compaction Test or Moisture Density Relation Test

94. Heavy rains occur the night before prior to your scheduled field

density test, are you going to pursue your schedule? Why?Answer: No, because the moisture content is high and can affect the result

95. Checking the gradation of composite aggregates and asphalt content of asphalt mix can be done by what test?Answer: Extraction Test

96. What is the device used in testing for liquid limit test?Answer: liquid limit device with grooving tool

97. What apparatus is used in plastic limit test?Answer: glass plate

98. How long does a vibrator be inserted in a concrete mix?Answer: not to exceed 15 seconds at 50 – 60 cm interval

99. Along the slope of high embankment _____ is provided as an erosion control measures and also to improve the stability of the slope.Answer: Berm

100. In soil and sub – surface explorations for flood control design of foundation condition, a soil sample was taken for field and laboratory tests. The test required for soil was taken, exceptAnswer: specific gravity, abrasion, water content, Atterberg Limits, gradation, compaction, relative density

101. Structure crossing above such covered underground drainage conduit shall be laid at least _____ above the top of the conduit.Answer: 1.0 m, 0.5 m, 1.5 m, 2.0 m

102. Class of stones for riprap ranging from 30 kgs to a maximum of 70 kgs with at least 50% of the stones weighing more than 50 kgs.Answer: Class B

103. Class of stones for riprap ranging from 15 kgs to a maximum of 25 kgs with at least 50% of the stones weighing more than 20 kgs.

Answer: Class A

104. Class of stones for riprap ranging from 60 kgs to a maximum of 100 kgs with at least 50% of the stones weighing more than 80 kgs.Answer: Class C

105. Class of stones for riprap ranging from 100 kgs to a maximum of 200 kgs with at least 50% of the stones weighing more than 1500 kgs.Answer: Class D

106. The maximum size of stone for stone masonry.Answer: 150 mm

107. The maximum size of aggregate for item 300.Answer: 1 inch

108. Required maximum liquid limit for Item 300.Answer: 35%

109. Required plasticity index range on Item 300.Answer: 4% to 9%

110. Range of sand size.Answer: 2.0 mm to 0.050 mm Ø

111. The ratio of the volume of voids to volume of solids.Answer: void ratio

112. The ratio of the weight of water to the weight of solids.Answer: moisture content

113. Significance of grading test are, exceptAnswer: Gives particle size distribution, measures permeability, capillarity, measures the potential cohesion of soil

114. Significance of plasticity index are, exceptAnswer: indicates compressibility, permeability, indicates the clay fraction of a binder material, measures the shearing resistance of soil

115. Properties of concrete are, exceptAnswer: workability, strength, durability, cracking

116. In roadway construction test on sub grade, the following will determine the economical thickness, exceptAnswer: embankment, base, surfacing, sub-base

117. The relative consistency of a cohesive soil in natural state.Answer: Liquidity Index

118. In Atterberg limit, the following are determined, exceptAnswer: shrinkage limit, liquid limit, plastic limit, group index

119. Minimum time for removal of forms and false works for centering under girders, beams, frames and arches.Answer: 14 days (minimum % of design strength – 80%)

120. Minimum time for removal of forms and false works for floor slabs.Answer: 14 days (minimum % of design strength – 70%)

121. Minimum time for removal of forms and false works for walls.Answer: 1 day (minimum % of design strength – 70%)

122. Minimum time for removal of forms and false works for columns.Answer: 2 days (minimum % of design strength – 70%)

123. Minimum time for removal of forms and false works for side of beams and all other vertical surfaces.Answer: 1 day (minimum % of design strength – 70%)

124. A mass of solid reinforced concrete cast around the head of a group of piles to ensure that act as a unit to support the imposed load.Answer: Pile cap

125. An embankment shall be compacted layer by layer.Answer: 150 mm

126. Class of concrete deposited in water.Answer: Class Seal

127. Class of concrete used in all superstructures and heavily reinforced substructures. The important parts of the structure included are slabs, beams, girders, columns, arch ribs, box culverts, reinforced abutments, retaining walls, and reinforced footings.Answer: Class A

128. Class of concrete used in footings, pedestal, massive pier shafts, pipe bedding and gravity walls, unreinforced or w/ only a small amount of reinforcement.Answer: Class B

129. Class of concrete used in thin reinforced sections, railings, pre-cast piles, cribbing, and for filler in steel grid floors.Answer: Class C

130. Class of concrete used in pre–stressed concrete structures

and members.

Answer: Class P

131. Height of dropping concrete to the point of deposit.Answer: 1.50 m

132. Reflectorized Thermoplastic Pavement Markings. What Item ______?Answer: Item 612

133. Permitted variation from the design thickness of layer for Item 300.Answer: + 15 mm and – 5 mm

134. Item 310 shall have a mass percent of air voids with range of _____.Answer: 3% to 5 %

135. Dowel bars for PCCP shall be _____.Answer: plain bars

136. Concrete beam sample when tested by Third – Point Method shall have a flexural strength of _____ when tested in 14 days.Answer: 3.80 MPa

137. When the required thickness of Item 200 is more than 150 mm, the

aggregate sub – base shall spread and compacted in ____

` Answer: two or more layers

138. Item 202 shall have a minimum soaked CBR value of _____.Answer: 80%

139. Permitted variation from design thickness of layer for Item 201.Answer: ± 10 mm

140. Sieve designation standard (in mm) for 0.425 mm to alternate US standardAnswer: No. 40

141. If slag is used as course aggregate for Item 311, the minimum density is _____Answer: 1,120 kg/m3

142. Minimum price allowed of contract for deficiency in strength of concrete specimens for PCCP which 10% to less than 15%.Answer: 70%

143. This joint is also called cold joint. It is constructed when there is an interruption of more than 30 minutes in the concreting operation.Answer: Transverse Construction Joint

144. Minimum variation of the surface from the testing edge of the straight edge between contacts with the surface in Item 310Answer: 6.0 mm

145. Portland Cement Treated Plant Mix Base Course (Item 206) after the completion of the final rolling, the surface will be treated with bituminous curing seal, how much is the rate of application?Answer: 0.5 L/m2 to 1.0 L/m2

146. In Item 201, the volume required in the project is 10,000 cu.m. The required number of CBR test is _____Answer: four (4)

147. Slump test of concrete determines the following, exceptAnswer: workability, fluidity, consistency, job density

148. The significance of liquid limit are the ff., exceptAnswer: measures the shearing resistance of soil, measures the potential cohesion of soil, fineness and shape of grain, Atterberg limits

149. In soil classification, 35% or less passing No. 200 sieve are the ff., exceptAnswer: A-1, A-2, A-3, A-4

150. To evaluate the performance quality of a soil as a highway subgrade material.Answer: Group Index

151. If the paving of concrete pavement will be done at the rate 200 ln.m, half width per paving day, how many sets of concrete beam samples shall be required. Given: A = 115,000 sq.m, width = 6.50 m, thickness = 230 mmAnswer: 353 sets

152. The required liquid limit for selected borrow toppings.Answer: 30%

153. The maximum plastic limit for selected borrow toppings.Answer: 6%

154. Soil is considered unsuitable material when the liquid limit and plastic limit exceedsAnswer: 80% and 55% respectively

155. Soil is considered unsuitable when the material density is ______________.Answer: 800 kg/cu.m or lower

156. The plasticity index is determined in accordance withAnswer: AASHTO T 90

157. The liquid limit is determined in accordance withAnswer: AASHTO T 89

158. The required compaction of embankment, layer by layerAnswer: 95%

159. The minimum compaction trial of embankment.

Answer: 10 m wide by 50 m long

160. At least how many days in – situ density tests should be carried out for each 500 m2 of each layer of compacted fill?

Answer: three (3)

161. Maximum plasticity index for Item 200Answer: 12%

162. Maximum liquid limit for Item 200Answer: 35%

164. The Los Angeles Abrasion Test for aggregate sub-base course is determined in accordance with.Answer: AASHTO T 96

165. The required abrasion loss for Item 200Answer: 50%

166. The minimum CBR required for Item 200Answer: 25%

167. The required soaked CBR for aggregate sub-base course is determined byAnswer: AASHTO T 193

168. Minimum required percent compaction of each layer of aggregate sub-base course.Answer: 100%

169. In – place density determination of aggregate sub-base course material shall be made in accordance withAnswer: AASHTO T 191

170. In some areas where the conventional base course materials are scarce or non – available, the use _____ allowable percent weathered limestone (anapog) blended with crushed stones or gravel.Answer: 40% (60% - crushed stones or gravel)

172. Maximum required percent abrasion loss for Item 202.Answer: 45%

173. Maximum required mass percent shall have at least one (1) fractured face of Item 202.Answer: 50%

174. Minimum required soaked CBR for Item 202.Answer: 80%

163. Maximum size of grading requirement for Item 200Answer: 2”

171. Maximum size of aggregate for base course material under grading BAnswer: 1 ½ inch

176. Maximum size of aggregate for Item 201 under grading AAnswer: 2”

175. Maximum size of aggregate for Item 202 under grading AAnswer: 1 ½ inch

177. Maximum size of aggregate for Item 202 under grading B.Answer: 1 inch

178. This item consists of a foundation for surface course composed of soil aggregate, lime, water in proper proportion, road – mixed and constructed on a prepared subgrade/subbase.Answer: Lime Stabilized Road Mix Base Course (Item 203)

179. The required plasticity index for Item 203Answer: 4% to 10%

180. Maximum required mass percent of wear for the aggregate on Item 203Answer: 50%

181. Maximum size of aggregate for Item 203 under grading A and BAnswer: 2”

182. Item number for water?Answer: Item 714

183. In Item 203, how much is the required mass percent of lime to be added to the soil aggregate?Answer: 3% to 12%

184. Minimum soaked CBR for Item 203Answer: 100%

185. Required percent compaction for Item 203

Answer: 100%

186. Equipment to be used for initial rollingAnswer: Pneumatic tire roller

187. Equipment to be used for final rollingAnswer: 3 – wheel tandem type steel wheel roller

188. The test on asphalt cement consisting of heating the asphalt in an open cup and passing a small test flame.Answer: flash point

189. It is a manually – operated device for deriving a measurement of roughness from the surface profile which may be expressed in terms of International Roughness Index.Answer: Merlin Road Roughness Measuring Device

190. It is used for the rapid in – situ measurement of the structural properties of existing pavement with unbound granular properties.Answer: Dynamic Cone Penetrometer

191. What is the thinnest cut – back asphalt?Answer: MC – 3000

192. In the construction of bridges projects, what is the method used to determine the casting length of the regular piles?Answer: Test Pitting

193. It is an equipment which is used to measure differential deflection between joints of a concrete pavement, to determine the modulus of the existing slabs for use in the design of an overlay, and to determine the remaining life of existing pavement.Answer: Falling Weight Deflectometer

194. What is the equipment used to pinpoint rebars, conduits, pipes, nails and other metals embedded in concrete before cutting or drilling?Answer: Rebar Locator

195. What is the instrument or equipment used to measure for surface test of concrete and asphalt pavements as soon as the concrete has hardened sufficiently or as soon as the asphalt mix has been initially compacted?Answer: 3 – meter straight

edge

196. What is the latest state of the art equipment consuming radioactive material which is commonly used in the compaction control of earth and asphalt road construction and in the measurement of moisture content?Answer: Nuclear Density Gauge

197. It is an instrument used to measure pavement deflections resulting from vehicle wheel loadings. The results of the elastic deformation tests are used to evaluate the structural condition of roads, and to help in the design of road strengthening measures and road capacity improvement.Answer: Benkelman Beam and

Deflection Logger

198. What is the instrument that is used for examining the quality of rigid materials such as rocks and concrete? This instrument is a non – destructive portable instrument with dimensions of 110 mm x 180 mm x 160 mm and its main uses includes the determination of concrete strength (either in – situ or pre – cast),also to determine the presence of voids, cracks and other imperfections.Answer: Pundit Ultrasonic

Concrete Tester

199. Soil stabilizing agentAnswer: Lime – for silty and

clayey soilCement – for sandy

soil

200. Water content at which soil passes

from plastic to liquid state.Answer: LIQUID LIMIT

201. Water content at which soil passes

from semi – solid to plastic state.Answer: PLASTIC LIMIT

202. Water content at which soil passes

from solid to semi – solid.Answer: SHRINKAGE LIMIT

203. Steel bars placed along longitudinal joints to hold the adjoining slabs together are called _____.

Answer: tie bars

204. The concrete pavement surface shows high spots of 15 mm in a 3 – m straight edge. The concrete in the area represented by these high spots _____.

Answer: shall be removed and replaced (but if high spots being noted exceeds 3 mm but not exceeding 12 mm, it shall be ground down only.

205. The calibration of the Universal testing

machine is conducted _____Answer: Once a year

206. What is the sampling requirement of

bituminous mixture?Answer: 1 sample per 130

tonnes

207. What is the depth of the thermometer

inserted in the bituminous mixture?Answer: 2”

208. In the design of bituminous mix, the design criteria for stability under the Marshall Stability Method for heavy traffic is ____

Answer: 1800 lbs

209. The stability criteria of the Marshall Stability Method is the maximum load resistance that a specimen will develop at _____

Answer: 60°

210. Bituminous mix specimens are compacted at how many blows at each end for a heavy traffic design under the Marshall Stability Method?

Answer: 75 blows

211. In a penetration test, if the penetration

is 9. What is the grade of the asphalt?

Answer: 85 – 100

212. In case of scarcity or non – availability of Type I Portland cement, what type of pozzolan shall be used?

Answer: Portland Pozzolan Cement

Type 1P

213. The required flexural strength of concrete beam sample of Item 311 when tested by the midpoint method.

Answer: 4.50 MPa

214. The required forms to be used in concrete pavement are _____.Answer: Steel forms of an

approved section

215. Sowing of the weakened plane joints

shall be done usually at _____.Answer: Within 24 hours

216. Removal of forms of concrete pavement __________.Answer: 24 hours

217. The required slump of concrete using

slip – form method of paving is _____.

Answer: 1 ½ inches

218. Deficiency in strength of concrete specimen wherein no payment of contract price allowed is _____.

Answer: 25% or more

219. What is the length of a lot of pavement

when a single traffic lane is poured?

Answer: 1,000 ln.m

220. What is the length of a lot of pavement when two lanes lane are poured concurrently?

Answer: 500 ln.m

221. What is the required size of concrete

beam sample?Answer: 150 mm x 150 mm x

525 mm

222. What is the required number of set of concrete beam specimens to be taken from each 330 sq. m of pavement of fraction thereof placed each day?

Answer: 1 set

223. What is the required compressive strength that concrete piles be

moved?Answer: 80% of the designed 28 – day compressive strength

224. The required circular pin diameter

used to bend 10 – 20 mm Ø reinforcing

steel. Answer: 6d (20 mm – 25 mm

Ø = 8d: 28 mm Ø and above = 10d)

226. What is the slump of concrete Class A

deposited in water?Answer: 10 to 20 cm

228. What item no. is Bituminous Surface

Treatment?Answer: Item 304

229. What is the required tolerance for bituminous material in job – mix formula for Item 310?

Answer: ± 0.4%

227. This item shall consist of preparing and treating an aggregate base course preparatory to the construction of a bituminous surface course.Answer: Prime Coat

230. This item consists of an application of bituminous material with or without the application of aggregate on existing bituminous surface?

Answer: Seal Coat

239. This item shall consist of preparing and bearing an existing bituminous or cement concrete surface with bituminous materials preparatory to the construction of bituminous surface course.

Answer: Tack Coat

232. What is the size of the sample in Item

310 taken for each full day’s operation?

Answer: 150 mm x 150 mm or 100mm Ø

231. Job – mix tolerance for temperature in

the mixture for Item 310.Answer: ± 10°C

233. What is the required temperature of

mix in item 310 when placed?Answer: 107°C

225. The mixing speed of the transit mixer

during batching.Answer: 4 to 6 rpm

234. The required speed in rolling in Item

310.Answer: 5 kph

235. It is the resulting difference in elevation across a joint or crack.Answer: faulting

236. In core specimen asphalt mix thickness determination, it shall have a diameter of at least ______.

Answer: 100 mm

237. In batching concrete mix, the accuracy

of cement content shall be _____.Answer: ± 1.0 mass %

238. Minimum thickness measured perpendicular to the slope using Class D stones for riprap.

Answer: 800 mm (Class A – 300 mm; Class B – 500 mm; Class C – 600 mm)

240. What is the rate of application of bituminous seal coat using asphalt cement? Answer: 0.9 to 1.8

lit/m2

241. What is the rate of application of bituminous seal coat using cut –

back asphalt? Answer: 1.5 to 3.0

lit/m2

242. What is the maximum tolerance of the variation of the surface of Item 310 from the testing edge of the straight edge between any two contacts with the surface?

Answer: 6 mm

243. What is the minimum dry compressive

of Item 310? Answer: 1.40 MPa

244. What is the required Index of Retained Strength of Item 310 when tested by AASHTO T 65? Answer: 70% minimum

245. Job – mix tolerance in Item 310 for

grading, passing No. 4 and larger sieve.

Answer: ±7

246. Job – mix tolerance in Item 310 for

grading, passing No 8 to No. 100 (inclusive). Answer: ±4

247. .Job – mix tolerance in Item 310 for

grading, passing No. 200 sieve. Answer: ±2

248. The property of asphalt mix to resist

deformation from imposed load.Answer: stability

249. The property of asphalt mix to resist the detrimental effects of air, water, temperature and traffic.

Answer: durability

250. The property of asphalt mix to withstand repeated flexing

caused by the passage of wheel loads.

Answer: fatigue resistance

251. The property of asphalt mix to bend slightly without cracking and to conform to gradual settlements and moments of the base and subgrade.

Answer: flexibility

252. The range of aggregates composition

in Item 310.Answer: 92% to 95%

253. What is the test on asphalt in order to determine the effect of water on the cohesion of the mix?Answer: Immersion – Compression Test

254. In temperate countries like the Philippines, what is the most commonly used grade of asphalt cement?

Answer: 60 – 70 and 85 – 100

255. To determine the thickness _____ of asphalt, Immersion – Compression Test is performed.

Answer: stability

256. Percent air voids will _____ as percent

asphalt increases in Marshall Stability.

Answer: decrease

257. To determine the temperature of delivered asphalt mix, what

apparatus is used?Answer: armored thermometer

258. Peat and muck soils are considered as:

Answer: highly organic soils

259. Why is it that a trial section is conducted in sub – base or base course construction?

Answer: to check the suitability of materials, efficiency of the equipment used and the construction method.

260. What does it mean when there is bleeding in a newly paved asphalt

road?

Answer: excessive asphalt content

261. A good subgrade soil should have the

following:Answer: low liquid limit and

low plastic limit

262. Concrete samples may be tested at an

earlier stage in order to _____Answer: determine the trend of

its strength development

263. What is the test criterion for reinforced concrete pipe tested in a three – edge bearing test machine?

Answer: 0.3 mm crack

264. In testing concrete cylinder sample, the applied load should be continuous without shock at a constant rate within the range of _____

Answer: 20 to 50 psi/second (compression); 125 – 175 psi/second (flexural)

265. Cement which has been in storage for a long period of time and that there is already doubt as to its quality should:

Answer: be retested prior to use

266. It is a process of improving the properties of soil to make it more suitable for a particular purpose.

Answer: Stabilization

267. Two tests are done in one lot sample. The test differs from each other, third test is taken. What will be this test? Answer: referee test

268. If no beam sample taken to determine the strength of concrete pavement, is it allowed in DPWH specs to use core samples to determine the strength. What is the required compressive strength?

Answer: Yes, 3,500 psi at 14 days

269. Tact coat must be at what condition

prior to the application of asphalt mix?

Answer: tacky

270. The use of sea water in reinforced

concrete may _____Answer: induce risk of

corrosion in reinforcing steel

271. Subgrade having a CBR value of 2% or

less is considered _____Answer: weak subgrade

272. Subgrade having a CBR value of 15%

or more is considered _____Answer: very stable

273. Subgrade other than those defined in

the two above categories is considered.

Answer: normal

274. What are the three (3) major groups of

soil?Answer: granular soil, fine

grained soil, organic soil

275. What is the significance of field density

test?Answer: to determine the degree of compaction of soil. It is also a control test in embankment construction to ensure adequate compaction.

276. Weighing hot sample is not advisable because it affects the accuracy of the result. True or false?

Answer: true

277. How to prepare or to come up with an

air – dried sample?Answer: air dry the sample

under the heat of the sun

278. If it is impossible to air – dry the sample under the heat of the sun, what alternative should be used?

Answer: oven – dry the sample @

60°C

279. Sample for compaction test should

pass to what sieve size?Answer: Method A & B – use

sample passing No. 4 Method C & D – use

sample passing ¾ inch

280. What is the difference between T – 99

and T – 180 compaction test method?

Answer: T – 99 uses 2.5kg (5.5lbs) rammer with a 12” drop while T – 180 uses 4.54 kg (10lbs) rammer with an 18” drop.

281. What is particle size analysis?Answer: It is the determination of particle size distribution in soils by sieve, hydrometer or a combined analysis

282. What kind of water shall be used in laboratory test especially if it deals with chemicals?

Answer: distilled water

283. Liquid limit brass cup w/ sample is raised and allowed to drop sharply on the base through a height of _____?

Answer: 10 mm

284. How many rotations per second will

the crank of a liquid limit be rotated?

Answer: 2 rps

285. In doing a plastic limit test, to what Ø

will the soil thread begin to break?Answer: 3.2 mm (1/8”)

286. What is specific gravity?Answer; It is used in a gravimetric – volumetric relationship in soils (or defined as the ratio of the wt. in air of an equal volume of water at a stated temperature)

287. What is the approximate area for density control strips?

Answer: 335 sq. m

288. What Item of work is embankment?

Answer: Item 104

289. What kind of material for Item 200?

Answer: Aggregate sub – base course

290. What is the required particle size for selected borrow for toppings under Item 104?

Answer: All particle size will pass sieve 75 mm or 3” openings and not more than 15 mass % will pass 0.075 mm. (AASHTO T 11)

291. What is the minimum degree of compaction for Item 200 and 201?Answer: 100%

292. What is the highest point in the moisture density curve of the moisture density relation test or compaction test?Answer: Maximum dry density (MDD) and Optimum moisture content (OMC)

293. What is the required size of calibrated sand used for field density test (FDT)?Answer: Any clean, dry, free – flowing, uncemented sand passing No. 10 and retained No. 200 sieve

294. What is the standard diameter of an orifice of an FDT sand cone?Answer: ½ inch (12.7 mm)

295. What are the apparatus used in FDT?Answer: sand cone, jug (at least 4 liters), guide plate, moisture cans, calibrated sand, weighing scale, oven with temperature control, chisel or digging tool, plastic bags and labeling materials (tag name)

296. How many hours does a fine aggregate tested for specific

gravity and absorption be soaked in water?Answer: 15 to 19 hours

297. How to determine if the fine aggregate reaches the saturated dry condition?Answer: It is determined by the use of cone test for surface moisture. If the molded shape of fine aggregate slumps slightly, it indicates that it has reached a surface dry condition

298. What are the tests required for concrete aggregates?Answer: Fine aggregate = grading, specific gravity, absorption, dry unit weight: Coarse aggregate = grading, specific gravity, absorption, dry unit weight and abrasion. Note: Soundness test is also performed as per request

299. What are the size or diameter and

weight of cast – iron spheres used in

abrasion test?Answer: Approximately 46.8

mm Ø and each weighing between 390 – 455 grams

300. What is the required total weight of sample for abrasion test of coarse aggregate, grading A with 12 as number of spheres?Answer: 5,000 grams ± 25

grams

301. What is significance of abrasion test?

Answer: It evaluates the structural strength of coarse aggregate. It gives an indication of quality as determined by resistance to impact and wear. It also determines whether the aggregates will have degradation during traffic or rolling.

302. What is the sieve used in sieving materials for abrasion test?

Answer: No. 12 (1.70 mm)

303. At what age should a concrete beam sample be tested for flexural test?

Answer: 14 days

304. How to compute the flexural strength of concrete beam sample tested at third point?Answer: R = PL

bd2

305. How to compute the flexural

strength of concrete beam sample tested at center point?Answer: R = 3PL 2bd2

306. What is the size of the tamping rod used is sampling concrete?

Answer: 16 mm Ø and 610 mm long with the tamping end rounded to a hemispherical tip of the same Ø as the rod.

307. Concrete masonry (hollow blocks) if subject to test, how many samples are required?

Answer: 6 pcs/10,000 units (12 pcs

if more than 10,000 units)

308. What is the strength requirement for load bearing concrete masonry units?

Answer:Individual = 5.5 MPa

(800 psi) minimumAverage (for 3 samples) = 6.9 MPa (1000 psi) minimum

309. What is the strength requirement for non – load bearing concrete masonry units?

Answer:Individual = 3.45 MPa

(500 psi) minimum

Average (for 3 samples) = 4.5 MPa (600 psi) minimum

310. What is the significance of testing reinforcing steel bars?

Answer: To determine the yield and tensile strength of the bar as well as its elongation and is used to classify the bars into grade.

311. What is the significance of bending test for RSB?Answer: To evaluate the ductile properties of RSB

312. What is the required testing requirement for paints?

Answer: 1 can (gal or pail)/ 100 cans (gal or pail)

313. SS – l or SS – lh is what kind of asphalt?Answer: slow – setting

emulsified asphalt

314. For how many hours or how long shall a bituminous prime coat be left undisturbed?

Answer: 24 hours

315. What kind of asphalt is used as tack

coat?Answer: cut – back asphalt

316. One (1) set of concrete cylinder sample shall be taken for every how many pieces of RCCP?Answer: 25 pieces

317. What is being determined in a core

sample from asphalt pavement?Answer: thickness and density

of pavement

318. All records regarding quality control such as accomplishment, daily activities, weather, etc. are recorded in a _____

Answer: Materials logbook

319. The Standard Penetration Test (SPT) is

an in – situ test that measures what?

Answer: depth of soil layer

320. The main problem associated with wrong practice of conveying concrete is called _____Answer: segregation

321. A one – lane road with a pavement width of 3.5 m and shoulder width of 0.5 m on each side of the pavement was designed to have sub-base and base courses with a combined thickness of 300 mm. If the thickness of the sub-base is 125 mm, the spreading and compaction of the base and sub-

base courses shall be carried out in?Answer: three (3) layers over

the full width of 4.5 m

322. During the application of the first half of the anticipated load a _____ rate of loading shall be permitted?Answer: higher

323. Quality of factory – produced RCCP

may be best established through what?

Answer: Test of concrete pipe samples

324. Soft and unstable soils were encountered during the course of subgrade preparation. If you were the ME assigned to the project, what is the most effective and cheaper method that you would recommend to stabilize the soil prior to the construction of the sub base course?Answer: geotextiles

325. How many times per layer should a concrete specimen molded in a 6” x 6” x 21” beam mold be rodded?Answer: 63 blows/layer

326. Rolling of bituminous mix shall be discontinued whenever it begins to produce excessive _______ or _______. Answer: pulverizing of the aggregate, displacement of the mixture

327. In placing concrete, the required temperature should be less than ____

Answer: 29ºC

328. How many concrete cylinder samples is required for a 300 pcs RCCP?

Answer: 12 sets

329. If concrete cylinder is not available for a 300 pcs RCCP, how many pipes shall be subjected to test?Answer: 6 pcs RCCP

330. If there is a necessity to add water to the concrete mix in order to increase its workability (provided concrete does not

excced specified slump), how many minutes after the initial time of mixing does adding water be permitted?Answer: not exceeding 45 minutes and that water – cement ratio is not exceeded.

331. What are the two (2) types of bitumen that are commonly used in the bituminous mixture?Answer:

TAR – is a viscous liquid obtained from the distillation of coal or wood.PETROLEUM ASPHALT – are the products of the distillation of crude oil.

332. What are the three (3) major petroleum asphalts?Answer: Asphalt cement, cut – back asphalt, emulsified

asphalt

333. What are the solvents of cut – back asphalts?

Answer:GASOLINE – for rapid – curing

typeKEROSENE – for medium curing

typeDIESEL – for slow curing type

334. Emulsified asphalts are either _____ or _____.

Answer: CATIONIC EMULSION – works better with wet aggregates and in cold weather. It is a positively charge electron.ANIONIC EMULSION - adheres better to aggregates which have positive charge. It is a negatively charge electron.

335. What is the bituminous material used in Item 310?

Answer: asphalt cement

336. What greatly affects the service of

asphalt cement?Answer: grade and quantity of

asphalt

337. What influences primarily the grade of

asphalt selected?Answer: climatic condition

338. How many weeks do the producer of asphalt mix or the contractor shall submit the job – mix formula?

Answer: three (3) weeks

339. Who will approve the job – mix formula?Answer: DPWH PE and ME

340. The job – mix formula contains provisions the following:Answer:

a. grading of aggregatesb. percentage and type of

asphaltc. temperature of

aggregates and asphaltd. temperature of mixture

upon delivery or time of compaction

341. When tar is used, what is the temperature that the mixture shall

be placed? Answer: 66ºC to

107ºC

342. When is the right time to compact in

order to attain the required density?

Answer: when the mixture is still

hot and workable

343. What is to be done in order to determine the number of passes that would attain the required density?Answer: trial section

344. What needs to be controlled during the mixing and compaction and is of great significance in the strength of the resulting pavement?Answer: temperature

345. In Item 310, how is rolling be done?

Answer: It should begin from the sides and proceed longitudinally parallel towards the center line, each trip

overlapping one half the roller’s width.

346. After the final rolling, what will be checked?Answer: degree of compaction

347. The compacted pavement shall have a density equal to or greater than _____Answer: 95% of the laboratory compacted density

348. When will the traffic be permitted to utilize the pavement?Answer: when the pavement has cooled to atmospheric temperature

349. How do we take sample from the finish pavement?Answer: by the use of core drill or saw

350. What is the allowable slump of a workable concrete if not vibrated?Answer: 40 mm – 75 mm

351. What is the allowable slump of a workable concrete if vibrated?Answer: 10 mm – 40 mm

352. When concrete is mixed in a central mixing plant, what is the time of mixing?Answer: not less than 50 seconds or more than 90 seconds

353. In transporting concrete, what is the time elapsed from the time water is added to the mix until the concrete is deposited in – place at the site?Answer: It shall not exceed 45 minutes if hauled in non – agitating trucks and 90 minutes if hauled in truck mixers or agitators

354. How is concrete consolidated?Answer: by the use of vibrator inserted in the concrete vertically

355. If the lanes are concreted separately, what kind of joint in a form of a keyway is used?Answer: longitudinal construction joint

356. What kind of bar is placed perpendicular to the joint stated in the preceding problem?Answer: deformed steel tie bars

357. What is the depth of the weaken plane joint when sawed with a

concrete saw? Answer: not less than 50

mm

358. The width of the weaken plane joint is

_____. Answer: not less than 6 mm

359. What shall be done if cracks appear at or near the joint prior to the time of sawing?

Answer: sawing shall be omitted

360. Tie bars shall not be coated or painted with _____Answer: asphalt or other

materials

361. What is the material that is used as a load transfer device held in a position parallel to the surface and center line of the slab of pavement?

Answer: dowel

362. To protect dowels from corrosion and to facilitate sliding in concrete, it shall be coated with _____

Answer: thin film of bitumen

363. The surface of the pavement shall be

roughened by means of _____Answer: brooming

364. What is the depth of corrugation produced by brooming in the surface of the pavement?

Answer: 1.5 mm

365. The surface of a newly put concrete when has sufficiently set shall be cured for a period of _____

Answer: 72 hours

366. The curing of the pavement is done

by means of the following:Answer:

a. by covering the concrete with mats saturated with water

b. by thoroughly wetting the pavement

c. by pondingd. by applying curing

compound immediately after finishing of the surface

367. When is the right time to seal the

joints?Answer: after the curing

period or before it is opened to

traffic

368. What is the difference between Item

504 and Item 505 (bluebook ’95)?Answer: the placement of stone or boulders and the ratio of cement and fine sand

369. The ME of the contractor is directly

under the supervision of the _____?Answer: Materials Engineer of

the DPWH

370. The requisites in transporting samples

of the laboratory is _____Answer: Well packed in durable containers to avoid damages in transit, accompanied by a sample card filled up in detail and duly signed by the ME

371. Who has the power to recommend the acceptance or rejection of construction materials for use in the project based on test results?Answer: Materials Engineer of the DPWH

372. It is a chemical composition of asphalt that gives color and hardness.Answer: asphaltene

373. The mineral filler which is used in the bituminous mix is passing sieve?Answer: No. 200

374. Cold mix asphalt is used in _____Answer: pothole patching

375. VMA meansAnswer: Voids in Mineral Aggregates

376. The compaction temperature in molding the bituminous mixture specimenAnswer: 124ºC

377. The mixing temperature of bituminous mix is Answer: 163ºC

378. The heating temperature of bituminous mix isAnswer: 121ºC - 188ºC

379. The heating temperature of aggregates ranges fromAnswer: 177ºC - 191ºC

380. The maximum absorption content of CHBAnswer: 240 kg/m3

381. The maximum moisture content of CHBAnswer: 45%

382. SPT meansAnswer: Standard Penetration Test

383. A tube sampler is used in sampling undisturbed sampleAnswer: Shelby tube

384. Used in sealing undisturbed sampleAnswer: wax

385. A tube sampler used in sampling disturbed sampleAnswer: split spoon sampler

386. It is a dynamic test used in the field to obtain rapid empirical results which can be used to estimate shear strength and bearing capacityAnswer: Standard Penetration Test

387. A type of coring bit used in rock coringAnswer: diamond bit

388. CQCA meansAnswer: Certificate of Quality Control Assurance (submitted weekly)

389. The specific gravity of asphalt ranges fromAnswer: 1.01 – 1.04

390. The type of electron present in rapid curing emulsified asphalt?Answer: cationic

391. How many group of three in – situ densities are required if the compacted volume of embankment laid was estimated to be 1,500 cu. m with a thickness of 200 mm/layer?Answer: fifteen (15)

392. The allowable % variation in mass of deformed reinforcing steel isAnswer: 6% maximum under nominal stress

393. The maximum allowable % phosphorous content of a deformed and plain billet steel bar isAnswer: 0.06%

394. Tensile and yield strengths of steel bars?Answer:TENSILE STRENGTH YIELD POINTGRADE 40 483 MPa 276 MPaGRADE 60 621 MPa 414 MPaGRADE 75 689 MPa 517 MPa

395. Plasticity index is an indication of

percent. Answer: clay content

396. The condition of the soil to be tested in the laboratory compaction test isAnswer: air – dried condition

397. The method in the determination of density of soil in – placeAnswer: Sand cone method

398. Air –dry sand used in the density apparatus is passing

Answer: sieve No. 10 retained No. 200

399. Which of the following items does not need CBR?Answer:

a. subbase materialsb. surfacing materials c. base course materials

400. In abrasion test, the abrasive charge

shall consist of cast – iron spheres or

steel spheres.Answer:

GRADING A – 12 spheresGRADING B – 11 spheresGRADING C – 8 spheresGRADING D – 6 spheres

401. In truck mixing, the minimum number

of revolutions after all ingredients including water is in the drum is Answer: 100 rpm

402. A maximum time of _____ shall be

permitted for wet mixing, lay down and

finishing when this method is used (Item 206)Answer: two (2) hours

403. Traffic shall be prohibited from traveling at the speeds in excess

of _____ until the asphaltic material

has set. Answer: 40 kph

404. Mortar shall be used within _____ after its preparation. Answer: 90 minutes405. In placing concrete for slab, using

buggies, the correct method that should be followed isAnswer: concrete should be

dumped into the face of the previously placed concrete.

406. There is a failure of flexural strength in the pavement, if you are the ME of your firm, what will you recommend?

Answer: conduct recoring

407. When loads have been arriving at the spreader with the material

peaked or doomed up and a load suddenly appears in which the material lies flat, it indicates

Answer: excessive asphalt

408. Where and when was the first use of Portland cement?

Answer: Bellafontaine,Ohio (1893)

409. The curve in the logarithmic scale where the 25th blow is projected in order to determine the liquid limit of the soil.

Answer: Flow curve

410. Percentage of wear represents the value of _____. Answer: abrasion loss

411. In the design of concrete mix, what is the volume of water in the concrete mix that produces a slump of 76.2 mm?

Answer: 24.7 liters

412. The standard fineness modulus of sand is about _____. Answer: 2.75

413. The standard packaging weight of cement. Answer: 40 kg/bag

414. It is an impervious membrane applied to concrete pavement before its initial setting that prevents rapid evaporation of water from the mix. Answer: curing compound

415. The type of paint that is used for zone marking, traffic lanes and parking spaces which is rapid drying, resistant to abrasion and weather conditions and possess improved visibility at night.

Answer: reflectorized paint

416. An ingredient in the paint that gives reflection during night time.

Answer: glass beads

417. The paint which is used on concrete or masonry units. Answer: Latex

418. The average loss in weight of three specimens in zinc coating test.

Answer: Triple spot test

419. One the three specimens in the triple spot test with lightest coating.

Answer: Single spot test

420. The type of paint that is used in wood surfaces. It is a special type of paint made with varnish as the vehicle.

Answer: Enamel

421. Group index is an empirical number ranging from 0 to 20 under average conditions of good drainage and adequate compaction. The supporting value of a material as subgrade may be assumed as an inverse ratio to its group index, that is a group index of zero indicates

Answer: good subgrade material

422. It determines the target density which is constructed at the beginning of the work on each course of material to be compacted.

Answer: Control strips

423. The instrument used in placing concrete in water in a compact mass in its final position.

Answer: tremie with 250 mm Ø

424. The maximum specific gravity of thermoplastic paint. Answer: 2.15

425. The softening point of a thermoplastic paint. Answer: 102.5ºC

426. The maximum drying time of thermoplastic paint. Answer: 10 minutes

427. The rate of application of traffic paint.

Answer: 0.33 lit/m2

428. The maximum drying time of traffic paint. Answer: 15 – 30 minutes

429. The minimum weight of sample for reflectorized paint. Answer: 10 kg

430. The apparatus used to measure the thickness or height of compacted bituminous paving mixture.

Answer: vernier caliper

431. It is used in calculating the unit weight of the mixture of the degree of compaction of the asphalt pavement.

Answer: Bulk specific gravity of compacted bituminous mixtures using saturated surface dry specimens.

432. The solvent in the extraction of bitumen. Answer: gasoline

433. The percent of bitumen is computed based on

Answer: mass of dry aggregates

434. The method used to determine the grading of aggregate extracted from bituminous mixture.

Answer: Mechanical analysis of extracted aggregates

435. A device used to determine the relative hardness of asphalt.

Answer: penetrometer

436. Volatization test which measures the relative proportion of asphalt to oil.

Answer: Distillation

437. The measurement wherein the asphalt begins to melt.

Answer: Softening point

438. The Index of Retained Strength (IRS) is computed through the formula

Answer: (Wet Stability/Dry Stability) x 100%

439. The temperature requirement in initial rolling for Item 310.

Answer: 200˚F to 225˚F

440. What is the color of asphalt when it is overcooked?

Answer: yellowish brown

441. How many gradation ranges for Hot Plant Mix bituminous pavement are there in the blue book?

Answer: seven (7)

442. How many gradation ranges for Cold Plant Mix bituminous pavement are there in the blue book?

Answer: two (2)

443. The cored sample of asphalt pavement is measured at

Answer: approximately quarter points

444. Too much asphalt in the bituminous mixes causes

Answer: bleeding

445. What is the plasticity index of mineral filler?

Answer: not greater than 4

446. The wearing away of pavement surface caused by dislodging of aggregate particle.

Answer: raveling

447. The interconnected cracks forming a series of small blocks resembling an alligator’s skin or chicken wire.

Answer: alligator cracking

448. It is prescribed in each project based on estimated quantities and specifies the kind and number of test of each item of work.

Answer: Minimum Testing Requirements

449. If the coarse aggregates are subjected to five cycles of sodium sulfate soundness test, the weighted loss shall not exceed

Answer: 10 mass %

450. If the fine aggregates are subjected to five cycles of sodium sulfate soundness test, the weighted loss shall not exceed

Answer: 12 mass %

451. Additives used in concrete mixing.

Answer: admixtures

452. The test that determines the resistance of aggregates to disintegration by saturated solutions of sodium sulfate or magnesium sulfate.

Answer: Soundness test

453. The design of concrete mix specified in the bluebook is based on

Answer: Absolute Design Method

454. The initial setting time of Portland cement is not less than

Answer: 45 minutes

455. The final setting time of Portland cement

Answer: 10 hours

456. The standard sand used in testing the mortar strength of Portland cement

Answer: Ottawa sand

457. The apparatus used to determine the fineness of Portland cement by air permeability

Answer: Blaine Air Permeability Apparatus

458. A mixture of cement and water is

Answer: cement paste

459. The apparatus used to determine the initial and final setting of Portland cement in the laboratory.

Answer: Gillmore needle

460. The compressive strength of cement mortar samples in 7 days is

Answer: 19.3 MPa

461. What is the appearance of the molded cement paste which fails to meet the autoclave?

Answer: crumbled

462. The critical number of days of curing of concrete

Answer: first seven (7) days

463. It is equally as important as testing, and the sampler shall use every precaution to obtain samples that will show the nature and condition of the materials which they represent.

Answer: sampling

464. A soil sample received from the field for subsequent tests by reducing aggregations of particles into sizes which will pass certain sieves.

Answer: disturbed samples

465. A procedure to recover relatively undisturbed soil samples suitable laboratory tests of structural properties.

Answer: thin – walled tube sampling

467. The representative who will witness the testing of materials in an accredited laboratory.

Answer: government

468. Samples obtained from the field with minimum disturbance by using any drilling equipment that provides clean hole before insertion of thin – walled tubes that is, both the natural density and moisture content are preserved as much as practicable.

Answer: undisturbed samples

469. The type of additive that is used to delay the setting of fresh concrete.

Answer: retarder

470. The type of additive that is used to attain maximum early compressive strength of concrete.

Answer: accelerator

471. The best enemy of construction.Answer: water

472. The following are considered unsuitable materials:

Answer: a. Materials containing

detrimental quantities of organic materials such as grass, roots and sewage

b. Highly organic soils such as peat and muck

c. Soils with LL exceeding 80% and/or PL exceeding 55%

d. Soils with a natural moisture content exceeding 100%

e. Soils with very low natural density, 800kg/m3

f. Soils that cannot be properly compacted as determined by the engineer

473. What is the spec of mass % passing in sieve No. 200, grading A for aggregate base course?

Answer: 0 – 12%

474. The rate of application of special

curing agentAnswer: 4 liter per 14 sq. m

475. The method of measurement for

determining the depth of the river channel. Answer: sounding

476. If the type of soil in Item 200 is non – plastic, what Atterberg limit test can be performed?

Answer: Liquid limit test

477. The minimum penetration of the

preservatives into the surface of timber is

Answer: 20mm

478. The engineer shall be notified at least _____ before the treating process of timber.

Answer: 10 days

479. All grout shall pass through a screen

with a _____ maximum clear opening.Answer: 2mm

480. The allowable height of fall in driving piles to avoid injury using gravity hammer.

Answer: 2.5m – 3.5 (concrete) 4.5m (timber)

481. This increases the shearing strength of aggregates of any size, shape and gradation.

Answer: Compaction

482. In general, soils high value of this and plasticity index are poor as engineering materials.

Answer: liquid limit of fines

483. The recommended thickness of Hot Mix asphalt overlay depending on the expected traffic and the modulus of the cracked and seated pavement section.

Answer: 3” to 5”484. Stabilization and under sealing

are recommended if the mean deflection is ____ or the differential deflection is ____.

Answer: greater than 0.14”, greater than 0.002”

485. Super plasticizers can reduce the water content by _____ and increase the 24 – hour strength by _____.

Answer: 25% to 35%, 50% to 70%

486. Loose material is removed from all joints, cracks and areas that have previously patched by asphalt by _____ with nominal _____ air pressure.

Answer: power sweeping and air

blowing, 100 psi

487. Admixtures which can help incorporate a controlled amount of air on the form moist in concrete during mixing without significantly altering the setting or the rate of characteristic of concrete.

Answer: air entraining admixtures

488. It is the activity of monitoring planned scheduled against actual and by speed task to make – up for the past or future loss of time.

Answer: Delivery control

489. Bowl – shaped holes of various sizes in the pavement surface.

` Answer: potholes

490. A form of plastic movement typified by ripples (surface waves) across the pavement.

Answer: corrugation

491. A form of plastic movement resulting in localized bulging of the pavement.

Answer: shoving

492. Longitudinal surface depression in the wheel paths.

Answer: rutting

492. It is the chief load – bearing of gravel road?

Answer: base or subbase course

493. The maximum distance of the discharge point from the point of deposit by pneumatic means.

Answer: 3 meters

494. It reduces the vertical compressive stress induced by traffic in the subbase and subgrade.

Answer: base course

495. Minimum separation of splices when staggered.

Answer: 40 times bar Ø

496. Consist of furnishing, placing and finishing concrete in all structures except pavements conforming to the lines, grade and dimension.

Answer: Structural concrete

497. Minimum grouting pressure of bonding tendons.

Answer: 0.6984 MPa (100 psi)

498. The main cross member of Bailey bridge that carry the roadway structure.

Answer: transom

499. Coring sampling shall be done at _____ interval by using split spoon sampler and the depth needed is _____.

Answer: one (1) meter,. 30m

500. What is the diameter of split spoon sampler?

Answer: 50mm

501. The uniform sampling run in core drilling.

Answer: 1.50m length

502. The initial diameter of bore hole.

Answer: 76mm

503. What is the core bit diameter?Answer: 67mm

504. The required spacing of bore holes along centerline of roads for 300 VPD traffic.

Answer: 250m (1.5m below subgrade)

505. The required spacing of bore holes along centerline of roads for less than 300 VPD traffic.

Answer: 500m (along centerline)

506. The required spacing of bore holes along centerline for new road on swampy or marshy ground.

Answer: 100m (2m along the centerline of new road)

507. The required spacing of bore holes for bridge project

Answer: 1 deep drill for each

abutment (30m run)1 boring for each pier for

multi – span (3m into the bed rocks)

508. The required spacing and depth of bore holes over foundation area of dam.

Answer: 60m spacing, 30m intermediate along centerline

Depth = ½ times base width

509. For ports and harbors projects:Answer: 30m to 150m; 1m below dredged bottom (12m minimum for piers & wharves)

510. For buildings (large area – greater than 930 m2):

Answer: 1 bore hole at each corner of the structure and one on the interior (9m below lowest foundation)

511. For buildings less than 930 m2

Answer: two (2) boring at opposite corners

512. This reflector shall be the short type having a minimum base area of 180mm x 140mm.

Answer: Flush Surface Reflector

513. Occurs on PCCP when the cutting of weakened plane is delayed.

Answer: shrinkage cracking

514. What is the primary purpose in establishing design criteria in design?

Answer: consistency

515. Positional tolerance of duct tubes during casting operations.

Answer: ± 4mm

516. This method is usually adopted when there is no visible evidence of termite infestation.

Answer: Cordoning

517. This method is used when soil shows termite infestation.

Answer: Drenching

518. Moisture content of rough lumber should not exceed _____

Answer: 22%

519. Moisture content of dressed lumber should not exceed _____

Answer: 14%

520. Design pressure of glass in glazed position.

Answer: 244 kg/m2

521. The minimum pressure of testing water tank.

Answer: 1,033.50 KPa

522. The minimum energy per blow of diesel hammer on concrete/steel pile at each stroke.

Answer: 831.48 kg/m

523. The minimum distance allowed for the top portion of the splice below ground line or seabed.

Answer: 2.5 meters

524. Consist of the excavation of river beds, bottom of creeks or esteros and other bodies of water.

Answer: dredging525. The slope of batter piles

Answer: 1:6

526. Longitudinal gutter grades shall not be flatter than ____

Answer: 0.12%

527. Allowance for sediments or debris provided in design

Answer: 20%

528. It is the digging of soil after the final marking of the building outline has been established on the ground.

Answer: Minor excavation

529. It requires wide excavation of total extraction bearing capacity.

Answer: footing

530. This shall be conducted for buildings three (3) storey and above.

Answer: Boring test

531. The minimum depth of CHB wall footing of other minor structure on the ground.

Answer: 700mm

532. The minimum depth of footing on a well compacted fill.

Answer: 100mm

533. Typically a plain or reinforced concrete that is usually provided to support a column.

Answer: Spread footing

534. Gabion dimensions are subject to tolerance limit of _____ of the manufactured state.

Answer: ± 3%

535. A field density result of 88% degree of compaction obtained on the subgrade indicates that

Answer: compaction of the subgrade fails the compaction specs and needs additional compaction

536. Liquid limit is usuallyAnswer: greater than plastic limit

537. The blue book requires that the base course be compacted at least

Answer: 100% modified proctor

538. As construction work progresses, you noticed that the delivered materials are different from the on tested passed. If you are in doubt, what will you do?

Answer: conduct immediate re – testing for verification

539. Which of the following is not the responsibility of the Materials Engineer?

Answer: a. sampling of materialb. analysis of test result of

materialc. scheduling of delivery

of materialsd. design of concrete mix

540. Measure of construction materials for

concrete structure shall beAnswer: volume

541. The moisture density curve if different from each soil. Which of the ff statement is true?

Answer: a. granular, well graded

soil generally have fairly high maximum density at low optimum moisture content

b. clay soil have lower densities at OMC than granular, well graded soil

c. granular, well graded soil have greater densities than uniform soil at OMC

d. none of the above

542. What should be done on the subbase course with existing moisture content of 10% higher than the optimum moisture content?

Answer: dry out to reduce moisture, spread to the required thickness and compact

543. The DPWH specs provide _____ tolerance for asphalt pavement thickness

Answer: - 5mm

544. Geosynthetics may be used forAnswer: filtration or drainage,

reinforcement, erosion control

545. Which of the ff. is not included in determining moisture content?

Answer:a. beam balanceb. ovenc. moisture cand. extruder

546. Steel bars are considered undersize if

Answer: its nominal diameter as determined by caliper doesn’t meet the manufactured size

547. Samples of aggregates for base course when tested for quality the requirements

except grading. What will you recommend?

Answer: reprocess the materials by blending

548. Concrete curing refers toAnswer: procedure done to maximize concrete strength

549. What is the most inferior type of soil as to its engineering properties?

Answer: organic

550. What is the testing soil that involves the application of energy and addition of water as lubricant?

Answer: Moisture – Density relation test

551. The dividing line between gravel and sand in concrete pavement is

Answer: No. 10

552. What is the volume of the mold using 6” for AASHTO T – 180 D method in compaction test?

Answer: 0.002124 m3

553. A material resulting from the disintegration, grinding or crushing of rock and which will pass 2.00mm sieve and be retained on the 0.075mm sieve

Answer: sand

554. What is ASTM?Answer: American Society for Testing & Materials

555. What is AASHTO?Answer: American Association of

State Highway & Transportation Officials

556. DPWH thru Bureau of Research & Standards has prepared a revised laboratorytesting procedure manual, in order to have be consistent with the latest methods as prescribed under

Answer: ASTM & AASHTO

557. What is the category of contractor that are required by DPWH to have laboratory equipments or apparatus in pre – bidding qualifications?

Answer: large

558. What is the maximum size of aggregate used in Item 104?

Answer: ½ of the thickness

559. What kind of material that passes .001mm sieve?

Answer: colloids

560. In soaking sample for CBR, the water should at least _____ above the specimen

Answer: 25mm

561. A natural or prepared mixture consisting predominantly of stone, gravel or sand and containing silt – clay materials

Answer: soil aggregates

562. A rock fragment usually rounded or semi – rounded with an average dimension between 75mm – 305mm

Answer: boulders

563. The process of cutting the branches around a tree on the roadside to make them denser and grow straight.

Answer: Pruning

564. The road near or abutting a bridge.

Answer: Approach

565. Settlement of right of way problems should be done

Answer: before the construction

work

566. Material that has the greatest load carrying capacity

Answer: sand and gravel

567. In hydrographic survey, sounding joints should be made at a maximum interval of

Answer: 20 meters568. The use of geofabric material to increase the strength of the subgrade

material for road construction is classified as

Answer: Soil Reinforcement Method

569. What to recommend if the surface test of newly asphalted which showed a lump

Answer: remove and replace the

pavement area with irregularity570. Controlled Density Method in embankment construction involves

Answer: Depositing and spreading materials in layers

of not more than 225mm depth, loose materials and extending to the full width of the embankment

571. What type of cracks will appear on concrete if it was not cured immediately after final placement especially during the first seven days?

Answer: Plastic shrinkage cracks

572. What is commonly used as curing media for fresh concrete?

Answer: Liquid membrane forming

573. What is the work sequence on cylinder specimen?

Answer: cylinder shall be prepared, cured and tested at the specified date

574. When to remove the false work of continuous structure?

Answer: when the 1st and 2nd

adjoining span on each side have reached the specified strength

575. It is generally either a soft soil composed largely of silt, clay, organic deposit or loose sand having high void rather and usually not high water content

Answer: Weak Subgrade

576. What is Twelve – Inch Layer Method Embankment?

Answer: the material shall be deposited and spread in layers not more than 300 mm in depth (12”) loose measure, parallel to the finished grade and extending to the full width of the embankment

577. What is Rock Embankment Method?

Answer: the material shall be deposited on the fill and push over the end of the fill by means of bulldozer. This method is only applicable to fill ≥ 1.2 m in depth. It shall not be placed within 600 mm of the other grade

578. What is Hydraulic Fill Method Embankment?

Answer: the material shall be taken from borrow locations and shall be deposited so as to form the grade and cross section and shall be thoroughly compacted

579. What is the principal factor used in determining the thickness of the pavement?

Answer: STRENGTH OF SUBGRADE (deterioration due to frustration move also be considered)

580. What is Placing and Removing Surcharge Method Embankment?

Answer: were unsuitable material is present under the embankment corrective work consists of placing a surcharge constructed to the full width of the road bed. The surcharge shall remain in place until the embankment has reached stability or the required settlement

581. What is Hydraulic Construction Method Embankment?

Answer: this involves the introduction of water into the embankment to accelerate consideration

582. Mixture of fine – grained aggregates, bituminous binder and water for surface sealing

Answer: slurry seal (bituminous slurry)

583. What is the formula for percentage of wear?

Answer:Percentage of wear, % =

(orig wt. – wt. retained @ sieve # 12) x 100

original wt.

584. Free bitumen on the surface of the pavement which creates a shiny, glass – like reflecting surface that usually becomes quite sticky

Answer: bleeding

585. Occurring usually at the transverse cracks joint caused by

excessive expansion of the slabs during hot weather

Answer: buckling

586. The splitting of concrete surface material from the concrete pavement

Answer: crushing

587. The authorized hauling of materials in excess of the free haul distance

Answer: Overhaul

588. If slurry (wet) lime is employed, what is the typical slurry ratio?

Answer: 1 tonne lime : 2 cubic meter of water

589. What is the amount of cement to be added to the soil aggregates in Item 204?

Answer: 6 – 10 mass % of the dry

soil

590. Who is the father of Soil Mechanics?

Answer: Dr. Karl Terzhagi

591. What is quality?Answer: It the degree of

excellence

592. What is control?Answer: Is to regulate

593. What is quality control?Answer: It is conformance to

requirements

594. What is assurance?Answer: it the degree of

certainty

595. What are the two kinds of control activities?

Answer: Inspection and Testing

596. What is the minimum distance of water table from subgrade level?

Answer: 4 – 5 feet

597. What is the process of combining two or more soil in suitable properties to produce good grading on gravel, sand, silt and clay?

Answer: Mechanic Stabilization

598. What is the common material employed in stabilizing the moisture content of soil or liquid and hydroscope in nature? It is an aid in the compaction process by slowing the rate of evaporation of moisture from the soil

Answer: Calcium chloride or rock salt

599. When do clay and granular soils become unstable?

Answer: Clay soil becomes unstable if moisture content increases. Granular material becomes unstable if it has dried

600. Why do liquid asphalt was introduced in road construction aside from asphalt cement?

Answer: It was introduced in order to save heating costs and from convenience in road – mixing or priming

601. The theory of concrete design mix is to

Answer: Optimize aggregate packing and optimizes properties of cement mortar

602. To optimize the properties of the cement mortar, one has to depend on

Answer: cement type, cement content and water content

603. What type of cement is the Ordinary Portland Cement (OPC)?

Answer: Type I

604. What type of cement is the Moderate Sulphate Resistant Portland Cement?

Answer: Type II

605. What type of cement is the Rapid Hardening Portland Cement?

Answer: Type III

606. What type of cement is the Low Heat Portland Cement?

Answer: Type IV

607. What type of cement is the High Sulphate Resistant Portland Cement?

Answer: Type V

608. What type of cement is the Portland Blast Furnace Slag Cement?

Answer: Type 1S

609. What type of cement is the Portland Pozzolan Cement?

Answer: Type 1P

610. Type I is for general use such asAnswer: pavements & sidewalks, buildings & bridges and tanks & water pipes

611. Type III cement is used forAnswer: early stripping of forms & high early strength

612. Type IV is used forAnswer: massive structures such as dams

613. Type V cement is used forAnswer: when sulphate content of groundwater is very high

614. The inventor of Portland cement was

Answer: Joseph Aspdin

615. Portland cement is composed of blended materials containing

Answer: calcium, alumina, iron and silica

616. The simple recipe of Portland cement is

Answer: 2 parts of crushed limestone, 1 part clay/pulverized shale, 1 pinch of iron ore, then 1 pinch of gypsum added to clinker

617. Pozzolan cement is composed of a raw material called

Answer: volcanic earth

618. The 75% compressive strength of Portland cement is composed of

Answer: C3S and C2S

619. The 25% setting time of Portland cement is controlled by

Answer: C3A and C4AF

620. When water is added to Portland cement, _____ process is developed

Answer: hydration

621. Calcium Silicate Gel (C–S–H) and lime [Ca(OH)2] are developed when _____ is added to Portland cement

Answer: water

622. When Portland cement contains a low C3A, it means

Answer: the setting time is larger

623. Surplus lime [Ca(OH)2] in Portland cement when mixed with water takes care of the concrete’s

Answer: alkalinity

624. Coarse aggregates can be taken from

Answer: crushed rock, slags and river gravel

625. The water required for concrete mix should be

Answer: fresh water

626. Sea water is deleterious to concrete mix unless on admixture is added because it contains

Answer: chloride627. The entrapped air in concrete is

Answer: accidental and unwanted

628. The entrained air in concrete isAnswer: deliberate and desirable

629. We use aggregate in concrete as

Answer: filler materials in concrete

630. Aggregates are important in concrete because they strongly influence:

Answer: the properties of concrete, its mix proportion and its economy

631. Which of the following is not deleterious material to concrete?

Answer:a. calciumb. chloridec. coald. sulphate

632. Over sanded and under sanded mixture require more water to be workable, but making it so will only result to sacrifice in

Answer: strength

633. Concrete in the area represented by the cores will be considered adequate if the average strength of the cores is equal to or at least _____ of the specified strength, fc’ and no single core is less than _____

Answer: 85% of f’c, 75% of f’c

634. Fine aggregate shall be rejected when it fails in the _____ for organic impurities

Answer: Colormatic Test

635. Portland cement may be/shall be rejected if:

Answer: it has partially set, it contains lumps of cake cement and it comes from a discarded or used bag

636. A measurement of the coarseness or fineness of aggregates

Answer: fineness modulus 637. An excess water needed for

absorption of coarse aggregatesAnswer: free water

638. What do you mean by SSD?Answer: Saturated Surface Dry

639. A general term relating to the character of a mix with respect to its fluidity

Answer: consistency

640. More silt and clay content to fine aggregates is

Answer: objectionable

641. Type A admixture is classified by ASTM C494 as

Answer: Water – reducing admixture

642. For core specimens, each lot will be divided into how many equal segments?

Answer: five (5)

643. The unit pressure greater than which progressive settlement occur leading to failure

Answer: bearing capacity

644. The recommended thickness of hot mixed asphalt overlay. Answer: 2”

645. In the test to determine the moisture content of samples, the beam balance should be sensitive up to. Answer: 0.1g646. If a sample can not be weighed

within the prescribed time after being removed from the oven, it will placed inside a

Answer: dessicator647. Plastic and finely grain soil will

require at least how many hours to dry at constant weight/mass

Answer: 4 hours648. A sample may be cooled at

room humidity and must be weighed after it has been removed from the oven within

Answer: 1 hour649. Drying the material sample in

the oven to constant weight at a prescribe temperature; the drying time depends on the kind of soil and size of sample. A 25-gram sample of sandy material will be dried in about

Answer: 2 hours650. Test conducted for buildings 3

storeys and aboveAnswer: Boring Test

651. A test to determine the moisture content of soil

Answer: calcium tri – chloride652. The aggregate crushing value

of strong aggregate is. Answer: low

653. The kind of asphalt used in overlaying seated pavement

Answer: hot – mix asphalt654. The minimum width of paved

sidewalk. Answer: 1.5 m655. The limit of water – cement

ratio of concrete. Answer: 0.50 – 0.60

656. A cement which has a cementitious effect. Answer: Portland cement

657. A concrete where compression is induced before the application of working load so that tension under these loads is reduced

Answer: Pre – stressing658. What laboratory test is used in

determining the phosphorus content of steel materials?

Answer: Phospho - molydate

659. What chemical property in the composition of steel material that will cause brittleness or cold shortness when its content goes beyond 0.05% to 0.10%. Answer: phosphorous

660. Base or sub base is extended beyond each edge of proposed concrete pavement

Answer: 0.60 m661. If you want to adjust the slump and the air content, how do you it?

Answer: ± 10 mm slump = ± 2

kg/m3 from (water)

± air entrapment = ± 3 kg/

m3 of average (water)662. In non – entrained concrete, what is

the range of % air entrained? Answer: 3% - 0.2% (small – bigger aggregates)663. In air – entrained concrete, what is

the range of air entrained?Answer: 8% - 3% (small –

bigger aggregates)

664. For a constant water – cement ratio, what will happen if air content is involved?

Answer: the strength of concrete is reduced665. What will happen if you lower

the water – cement ratio and maintaining other values of its ingredients?

Answer: it will acquire strength666. What is the mixing time of concrete?

Answer:1.5 m3 capacity mixer, T ≥

60 secondsAbove1.5 m3 capacity

mixer, T ≥ 90 seconds

667. When cement is in contact with moist aggregates, batch made by mix will be disallowed beyond ____

Answer: 1 ½ hours

668. How many hours should an aggregate be washed and stockpiled before batching starts?

Answer: 12 hours prior to batching shall be stockpiled or binned for draining

669. When will truck mixing start?Answer: mixing shall begin

within 30 minutes upon cement has due added 15 minutes when wet aggregates is used, as 32ºC temperature is present

670. Concrete delivered by agitation of truck mixer must be discharged within 1 hour or 250 revolutions of the drum or Olader. Why?

Answer: to avoid over mixing and initial setting of concrete

671. In final computation of concrete in road to be paid, what is the maximum size of pipe that is negligible in the volume computation?

Answer: pipes with Ø of 4” or less