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BACHELOR OF QUANTITY SURV
BUILDING MAT
BLD
Lee Kim Thiam 03171Na Yeow Sing 03203
Ng Jia Nan 03214
Parvesh Ferag 03207
Steven Chan Kai Tiong 03198
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Vebe Consistometer Test
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Vebe Consistometer Test
Measure the consistency of stiff toextremely dry concrete.
Consistency is the durationneeded for a specific mass of
concrete to be consolidated byvibrating in any shaped mould.
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Benefits?
ADVANTAGES The Vebe consistometer is adynamic test and can be used onconcretes that are too dry forthe slump test.
Test results are obtaineddirectly.
DISADVANTA Unsuitable for field uthe need to ensure thvibration is kept withdevice.
Only works for low slu
concretes. No analytical treatme
test method has beendeveloped.
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KINDLY REFER TO TIMES FOR VIDEO
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Concrete Strength and worka
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Concrete Strength and workability af
water-cement ratio as per required s
Extra water can lubricate the particles in mixture, the more th
easier the flowing. However, too much water will cause segrega
Water-cement ration increase, the fluidity increase
Abramslaw states that higher the water-cement ratio, lower is
of concrete.
Every 1% increase in quantity of water added, reduces the
concrete by 5%.
Every extra liter of water will approximate reduce the strengt
by 2 to 3 N/mm and increase the workability by 25mm.
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Concrete Strength and workability a
quality and quantity of water
Quality of water used in concrete: Water used for mixing and curing shall be clean and
injurious amounts.(ex: oils, salts, sugar, acids and etc
Potable water is generally considered satisfactory for
concrete.
The ph value shall not be less than 6.
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Quantity of water:The quantity of water in the mix plays a vital role on th
of the concrete.
The range of water cement ratio between 0.40 anshown to produce the strongest concrete.
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Concrete Strength and workability af
aggregate-cement ratio
Concrete is formed by mixing mainly water, aggregates and sadmixtures.
For a given cement and acceptable aggregates. The strength
developed by a workable is influenced by the following:-
Ratio of cement to mixing water.
Ratio of cement to aggregates, the strength of the mort
bond between the mortar.
Grading, surface textures, shape, strength and stiffness o
particles.
Maximum size of aggregates.
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So, strength of concrete is directly related to the structure of t
cement paste.
Air in concrete produces voids.
Excess of water in the concrete evaporate and leave the voids.
Consequently, as the W/C ratio increases, the porosity of the cein the concrete also increases.
As the porosity increases, the compressive strength of the conc
decreases.
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THE END