Feasibility of Using Pulse Velocity to Evaluate Asphalt ... · 2.6. Ultrasonic Pulse Velocity Test...

Journal of Advances in Civil Engineering and Construction Materials 2018; 1(1): 51-63

51

Research Article Open Access

Feasibility of Using Pulse Velocity to Evaluate Asphalt Concrete

Properties

Saad Issa Sarsam1*, Nazar Sajad Kadium2

1Professor, Department of Civil Engineering, College of Engineering, University of Baghdad, Iraq.

2MSc. Student, Department of Civil Engineering, College of Engineering, University of Baghdad, Iraq.

Abstract

The construction of asphalt concrete pavement is usually accompanied by the quality control measures during

spreading and after compaction. Samples are usually obtained to verify the various strength and volumetric

properties of the asphalt concrete mixture. Such sampling and testing are time and labor consuming. A desirable

method is the one which neither causes disruption to traffic, nor causes any damage to the existing pavement

structure. Highway transportation agencies are moving towards the use of innovative non-destructive testing

(NDT) methods for evaluating the in-situ condition of pavement structures. For quick acquisition of test data, a

reliable and consistent test technique is needed. NDT methods provide all these features and are ideally suited

for application to pavements. In this investigation, the feasibility of implementing non-destructive testing

technique was investigated using pulse velocity to investigate the strength and volumetric properties of asphalt

concrete wearing course. Specimens were prepared in the laboratory at various asphalt percentages and tested

for pulse velocity, then subjected to indirect tensile strength and punching shear strength determination. The

impact of moisture damage and testing temperature on pulse velocity were also investigated. Data were

analyzed and modeled. It was concluded that implementation of non-destructive testing with the aid of pulse

velocity is feasible for predicting the quality of asphalt concrete within the limitations of the testing program

implemented. The good correlation between the pulse velocity and the volumetric and strength properties

demonstrates the potential benefit of using the wave parameters for condition assessment of asphalt concrete.

The moisture damage exhibits negative influence on pulse velocity by 13%, while the testing temperature shows

JOURNAL OF ADVANCES IN CIVIL ENGINEERING AND CONSTRUCTION MATERIALS

Journal Home Page: https://uniquepubinternational.com/upi-journals/journal-advances-civil-

engineering-construction-materials-jacecm/

Copyright: © 2018 Unique Pub International (UPI). This

is an open access article under the CC-BY-NC-ND License

(https://creativecommons.org/licenses/by-nc-nd/4.0/).

Correspondence to: Sarsam SI. Department of Civil Engineering, College of Engineering, University of Baghdad, Iraq. Email: [email protected]

Funding Source(s): NA How to Cite: Sarsam SI, Kadium NS. Feasibility of Using Pulse Velocity to Evaluate Asphalt Concrete Properties.

Journal of Advances in Civil Engineering and Construction Materials 2018; 1(1): 51-63. Editorial History:

Received : 12-11-2018, Accepted: 21-01-2018,

Published: 18-03-2019


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no significant influence on pulse velocity.

Key words: Non-destructive test, pulse velocity, asphalt concrete, tensile and shear, volumetric properties.

1. Introduction

More recently, NDT methods, including lasers, ground-penetrating radar, falling weight deflectometers,

penetrometers, and infrared and seismic technologies, have been significantly improved and have shown

potential for use in the quality assurance of Hot Mix Asphalt (HMA) pavement construction [1]. Using non-

destructive testing (NDT) techniques to evaluate asphalt concrete mixtures have been investigated by several

researchers for the past few decades. Some examples are application of ultrasonic pulse wave velocity (UPV),

impact resonance (IR), resonant column (RC), and acoustic emission (AE) tests towards characterization of

asphalt concrete specimens [2]. Results from the study by [3] have shown that NDT is a viable technique for

evaluating the structural capacities and overlay requirements for roads and streets. Analysis of the deflection

test data has been shown to be a complex task with results depending on several factors including the selection

of criteria, climate, and traffic considerations. However, there are some limitations in each of NDT methods

when they are used individually [4]. These limitations have not been fully studied and understood. For example,

the UPV method is one of the most commonly used wave-based methods in NDT. Yet, its potential for assessing

the quality of materials is limited because of the different variables that affect the relationship between strength

and velocity. This may be the reason why a poor correlation between the wave propagation parameters

determined from the standard pulse velocity test method [5] and the field rutting was reported by the Federal

Highway Administration (FHWA) [6]. Field and laboratory studies using data derived from in-situ were estimated

by [7] to the value of Marshall Stability. To this aim, pulse, Marshall, deflection, elasticity modulus, wet density,

moisture, and air void data were used as input variables. The artificial neural network (ANN) approach was used

for estimation. Various combinations of network architecture were examined in order to develop the optimum

ANN model. Correlation values were obtained as 0.71 for the training set, and 0.75 for the testing set,

respectively, for the best configurations. These obtained values are good, but it is not perfect. These coefficients

may be related with aging of bitumen, the number of samples, and the core drilling locations. UPV test was

investigated by [8] for evaluation of the behavior of HMA mixtures. The effect of different mixtures parameters,

including gradation, bitumen and filler contents are studied by means of UPV test and its comparison with

experimentally derived values. It was concluded that a specific bitumen content could be determined at which

the wave velocities exhibit a marked rise and after which both velocities start to decrease. The dynamic modulus

of asphalt mix was determined using Ultrasonic Pulse Velocity by preparing Marshall Samples in laboratory scale,

considering sample’s geometric density and bulk density respectively. However experimental results reveal that

higher reliability has been obtained by considering its bulk density [9]. [10] discusses some of the emerging as

well as contemporary Non-Destructive Evaluation (NDE) methods which have found applications for structural

evaluation of asphalt pavements. Underlying principles and test set-up of various techniques along with their

scope and performance are discussed in detail. Discussion is confined to the NDE methods specific to the

estimation of in-situ thickness of asphalt pavement layers. It does not specifically cover the issues related to


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estimation of density, moisture content, etc. The effect of mix parameters on the UPV test was investigated by

[11]. It was concluded that for all the mixtures with different percentages of fractured particles and filler

content, a specific bitumen content could be determined at which the wave velocities exhibit a marked rise and

after which both velocities start to decrease. Finally, the UPV test was observed to be sensitive to the

compaction method. As stated by [12], seismic measurements provide a truly non-destructive alternative to

characterize material properties of asphalt concrete in both laboratory and field as stated by [13]. Therefore,

seismic measurements can be an efficient technique to improve the knowledge of the quality of roads by better

quality controls and quality assurance of pavement structures. This can lead to improved production and

maintenance of pavements. The UPV was measured by [14] on cylindrical HMA specimens prepared using 60/70

asphalt cement and crushed limestone at three different aggregate gradations (maximum nominal aggregate

size equal to 12.5, 19.0 and 25.0 mm). The UPV measurements were performed. The collected data were

analyzed for the possibility of using UPV to predict fatigue life of HMA. The results indicated that UPV was found

to be higher in HMA prepared using higher sizes of aggregate.

2. Experimental

2.1. Asphalt Cement

Asphalt cement was obtained from Dora refinery; the physical properties are listed in Table 1.

Table1. Physical properties of asphalt cement.

*SCRB Specification [15] Unit Result Test Procedure as Per [5]

40-50 1/10mm 43 Penetration (25 ºC, 100g, 5sec) ASTM D 5

≥ 100 Cm 156 Ductility (25 ºC, 5cm/min). ASTM D 113

50-60 ºC 49 Softening point (ring & ball). ASTM D 36

After Thin-Film Oven Test ASTM D-1754

< 55 1/10mm 31 Retained penetration of original, % ASTM D 946

> 25 Cm 147 Ductility at 25 ºC, 5 cm/min, (cm) ASTM D-113

- % 0.175 Loss in weight (163 ºC, 50g, 5h)% ASTM D-1754 *SCRB: State Commission for Roads and Bridges.

2.2. Coarse and Fine Aggregates

Coarse and fine aggregates have been obtained from Al-Nibaee quarry, Table 2 illustrates the physical

properties of coarse and fine aggregates.

Table 2. Physical properties of Al-Nibaee coarse and fine aggregates.

Fine Aggregate Course Aggregate Property

2.631 2.610 Bulk Specific Gravity (ASTM C 127 and C 128)

2.6802 2.641 Apparent Specific Gravity (ASTM C 127 and C 128)

0.542 0.423 Percent Water Absorption (ASTM C 127 and C 128)

- 20.10 Percent Wear (Los-Angeles Abrasion) (ASTM C 131)

2.3. Mineral Filler

The mineral filler passes sieve No. 200 (0.075 mm). The filler used in this work is limestone dust and was

obtained from Karbala governorate. The physical properties of the filler are presented in Table 3.


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Table 3. Physical properties of filler (Lime stone dust).

Value Property

2.617 Bulk specific gravity

94 % Passing Sieve No. 200

2.4. Selection of Asphalt Concrete Combined Gradation

The selected gradation in this work follows the SCRB [15] Specification for dense graded wearing course, with

12.5 (mm) nominal maximum size of aggregates. Table 4 exhibits the selected aggregate gradation.

Table 4. Gradation of aggregate for wearing course.

Percentage Passing by Weight of Total Aggregate Sieve Opening (mm)

Gradation Adopted Specification Limits (SCRB*) [15]

100 100 19

95 90-100 12.5

83 76-90 9.5

59 44-74 4.75

43 28-58 2.36

13 5-21 0.3

7 4-10 0.075 *SCRB: State Commission for Roads and Bridges.

2.5. Preparation of Hot Mix Asphalt Concrete

The aggregate was dried to a constant weight at 110 ºC, then sieved to different sizes, and stored. Coarse and

fine aggregates were combined with mineral filler to meet the specified gradation shown in Table 4. The

combined aggregate mixture was heated to a temperature of (150 ºC) before mixing with asphalt cement. The

asphalt cement was heated to the same temperature of (150 ºC), then it was added to the heated aggregate to

achieve the desired amount and mixed thoroughly using mechanical mixer for two minutes until all aggregate

particles were coated with thin film of asphalt cement. Marshall Size specimens were prepared in accordance

with American Society for Testing and Materials (ASTM) D1559, [5] using 75 blows of Marshall hammer on each

face of the specimen. The optimum asphalt content was determined as per the procedure above to be 5% by

weight of aggregates. The prepared Marshall Size Specimens were divided into three sets, the first set was

subjected to the indirect tensile strength test at 25 ºC and 40 ºC, while the second set was subjected to double

punching shear strength determination at 60 ºC. The third set was subjected to moisture damage as per the

procedure by American Association of State Highway and Transportation Officials (AASHTO) [16]. Additional

asphalt concrete specimens have been prepared using asphalt cement of 0.5% above and below the optimum

asphalt content. Specimens have been tested in triplicate, and the average value was considered for analysis.

Plate 1 shows part of the prepared specimens.

2.6. Ultrasonic Pulse Velocity Test

The portable ultrasonic non-destructive digital indicating tester (Pundit) was used in this study. The device

generates and receives ultrasonic waves and has a digital display of the results, and it can be used with piezo

electric transducers over a frequency range from 20 to 500 kHz, a frequency of 54 kHz and accuracy of 0.1 was

used through this study to measure the pulse velocity for the specimens. The direct transmission arrangement

was used in this study. The pulser and receiver were placed on opposite HMA specimen surfaces. The pulse


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velocity is one of non-destructive tests determined according to ASTM [5]; BS [17-19] before starting destructive

tests and to ensure the extent of possible induced cracks in the specimens. Calibration of the pundit was done

before testing to check the accuracy of the transit time measurements. This is achieved by the calibration with

the reference bar. Vaseline was used as couplet between the transducer and the HMA specimen’s surface. A thin

layer of grease was applied on the surface of the tested points to act as a couplet and to prevent dissipation of

transmitted energy. The pulse transit path length was measured accurately, and the time of its travelling was

recorded. The distance between the transducers, which was equal to the HMA thickness, was divided by the

time measured to calculate the wave’s velocity. Eight readings were performed and averaged for each specimen.

The pulse velocity is evaluated by using Equation (1), the ultrasonic pulse velocity test setup is demonstrated in

Plate 2.

V = L / T (1)

Where:

V: Ultrasonic pulse velocity (Km/sec),

L: The path length (mm), and

T: The transmit time (µsec).

2.7. Indirect Tensile Strength Test

The indirect tensile strength test was conducted following the procedure of ASTM [5]. Marshall Size Specimens

were stored in the water bath at 25 ºC and 40 ºC for 30 minutes and then each specimen was centered on the

vertical diametrical plane between the two parallel loading strips of 12.7 mm width. Vertical compression load at

rate of 50.8 mm/min by Versa tester machine was applied until the dial gage reading reached the maximum

load resistance. The indirect tensile strength (ITS) was calculated using the following equation 2 [5].

ITS = 2000 ×P

π×T×D (2)

Where,

ITS = indirect Tensile Strength, kPa.

P = maximum load resistance at failure, N.

D = diameter of specimen, mm.

T = thickness of specimen immediately before test, mm.

2.8. Double Punching Shear Strength Test

This test procedure was reported and cited by many studies [20, 22]. It was used to measure the resistance to

punching shear. Marshall Size Specimen used for this test was immersed in water bath at 60 ºC for 30 min. The

test was performed by centrally loading the cylindrical specimen, using two cylindrical steel punches placed on

the top and bottom surface of the sample. The specimen was centred between the two punches 2.54 cm in

diameter, perfectly aligned one over the other, and then loaded at a rate of 2.54 cm/minute until failure. The

reading of dial gage at the maximum load resistance was recorded as unconditioned Punching Shear Strength


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(PST). The punching shear strength was computed using equation 3. Plate 3 exhibits the tensile and shear

strength test setup.

𝜎𝑡 = 𝑝 / (1.2𝑏ℎ − 𝑎2) (3)

Where,

𝜎𝑡 = punching stress, Pa

P= maximum load, N

a= radius of punch, mm

b=radius of specimen, mm

h=height of specimen, mm

Plate 1. Part of the prepared specimens.

Plate 2. Ultrasonic pulse velocity test setup.


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Plate 3. Tensile and shear strength test setup.

Plate 4. Specimens under moisture damage process.

2.9. Testing for Moisture Damage

The third set of asphalt concrete specimens was subjected to moisture damage as per the procedure described

by AASHTO [16, 21-22]. The set was divided into two groups, the first group was denoted as unconditioned

specimens which was tested for Indirect Tensile Strength (ITS) at 25 °C. The second group of Asphalt concrete

specimens were immersed in water at 25 °C into the desecrator and subjected to saturation under vacuum

pressure of 3.74 kPa for ten minutes, then the specimens were removed from the water chamber and stored in

a deep freezer for 16 hours at (-18) °C. Specimens were withdrawn from the deep freezer and allowed for

thawing for 120 minutes in air then specimens were transferred into a water bath and stored for 120 minutes at

60 ºC. Specimens were denoted as conditioned specimens then stored at 25 °C for 120 minutes before testing

for ITS. Plate 4 exhibits the specimens under moisture damage process.


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3. Results and Discussion

In this study, a 50 kHz frequency ultrasound wave was implemented to test asphalt concrete specimens. Such

frequency was recently employed by [23]. Even though asphalt concrete is a viscoelastic material, the theory of

elasticity can be used since the displacements and corresponding strains are very small and the actual

movements are very short in duration. This is a reasonable assumption because the tests were conducted at 25

°C. For the sake of simplicity, the asphalt mixture can be assumed to be a homogenous, isotropic solid [24-25].

The ultrasonic device consists of a pulse generator and a timing circuit, coupled with piezoelectric transmitting

and receiving transducers. The use of the UPV test is simple, quick, and non-destructive and requires

inexpensive testing equipment and setup. In the UPV test, a pulse wave emitted by a transmitter propagates

through the material and is detected by a receiver. The propagation of the low-strain mechanical waves can

assess the state of materials without causing damage. The distance between transducers is divided by the

measured travel time of the stress pulse to compute the wave velocity, which is related to the modulus of the

asphalt concrete.

3.1. Influence of Volumetric Properties on Pulse Velocity

As demonstrated in Figure 1, the pulse velocity increases as the volume of voids filled with asphalt VFA increase,

this could be attributed to the blocking of voids with asphalt cement which reduces the total available air voids

percentages and allowing the ultrasonic pulse wave to traverse the specimen quickly. Figure 2 exhibits the

increment of pulse velocity with the reduction of total volume of voids in the specimen. Similar behavior could

be observed regarding the better propagation of pulse through the specimen as the voids decreases.

As demonstrated in Figure 3, the pulse velocity increases with the increment of bulk density. Such behavior may

be related to the reduction of total voids in the mixture due to the compaction process. On the other hand,

Figure 4 exhibits the increment in pulse velocity with the increase in asphalt cement. The asphalt cement will

cover the aggregates with a thin film in addition to filling some of the voids which facilitates the propagation of

the ultrasonic pulse through the asphalt concrete specimen.

3.2. Influence of Strength Properties on Pulse Velocity

Figure 5 exhibit the increase in pulse velocity with the increase in Marshal stability, this could be attributed to

the fact that Marshall stability increases as the density of asphalt concrete increase. On the other hand, Figure 6

Shows that the pulse velocity increases as the flow value increase, this could be related to the fact that the

increase in asphalt content could increase the flow values.

Figure 7 exhibits the influence of shear strength on the pulse velocity, it can be observed that as the punching

shear increases, the pulse velocity increase. This may be attributed to the fact that shear strength is mainly

depended on the particle interlock and adhesion of the binder with aggregate. Such adhesion requires more

asphalt cement which will block the voids and facilitates the propagation of the ultrasonic pulse through the

asphalt concrete specimen.


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Figure 1. Pulse velocity-VFA relationship. Figure 2. Pulse velocity- Total Voids relationship.

Figure 3. Pulse velocity- bulk density relationship. Figure 4. Pulse velocity- Asphalt content relationship.

Figure 5. Pulse velocity- Marshal stability relationship. Figure 6. Pulse velocity- flow relationship.


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3.3. Influence of Testing Temperature and Indirect Tensile Strength on Pulse Velocity

As demonstrated in Figure 8, asphalt concrete specimens were tested for indirect tensile strength ITS. Two

testing temperatures (25 and 40) °C have been implemented. It can be observed that the testing temperature

has no significant impact on pulse velocity in general, although the lower testing temperature of 25 °C exhibit

higher ITS as compared to that at 40 °C.

Figure 7. Punching shear-Pulse velocity relationship. Figure 8.Tensile strength-Pulse velocity relationship.

3.4. Influence of Moisture Damage on Pulse Velocity

Figure 9 exhibit the influence of moisture damage on pulse velocity, it can be noted that asphalt concrete

specimens after practicing the moisture damage cycle (conditioned) shows lower pulse velocity by 13% than

that of (unconditioned) case. This could be attributed to the possible micro cracks initiated during the freezing

stage of the test and to the possible stripping occurred during the thawing stage of the test. The mathematical

models affixed to the previous relationships of pulse velocity with volumetric and strength properties and their

coefficients of determination indicate that the models can significantly explain the variation in ultrasonic pulse

velocity during its propagation through the asphalt concrete specimens. It can be concluded that implementing

the NDT in the determination of asphalt concrete properties is feasible.

Figure 9. Influence of moisture damage on pulse velocity.


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4. Conclusions

Based on the testing program, the following conclusions are drawn.

4.1. The ultrasonic pulse velocity increases as the asphalt content, bulk density, and volume of voids filled

with asphalt VFA increase, while it decreases as the volume of voids increases.

4.2. The ultrasonic pulse velocity increases as the Marshal stability, flow, shear and tensile strengths

increases.

4.3. The moisture damage exhibit negative influence on pulse velocity by 13%, while the testing temperature

shows no significant influence on pulse velocity.

4.4. The mathematical models relating pulse velocity with volumetric and strength properties indicates that the

models can significantly explain the variation in ultrasonic pulse velocity during its propagation through

the asphalt concrete specimens.

4.5. Implementing the NDT in the determination of asphalt concrete properties is feasible.

5. Conflicts of Interest

The author(s) report(s) no conflict(s) of interest(s). The author along are responsible for the content and writing

of the paper.

6. Acknowledgments

NA

7. References

1. Quintus H, Rao C, Minchin R, Nazarian S, Maser K, Prowell B. NDT Technology for quality assurance of

HMA pavement construction. NCHRP Report 626, 2009.

2. Tavassoti-Kheiry P, Boz I, Chen X, Solaimanian M. Application of ultrasonic pulse velocity testing of asphalt

concrete mixtures to improve the prediction accuracy of dynamic modulus master curve. Proceedings of

Airfield and Highway Pavements, ASCE, 2017.

3. Grau R, Alexander D. Nondestructive testing, evaluation, and rehabilitation for roadway pavements:

Warren County, Mississippi, Cincinnati, Ohio, and Berkeley, California. IWR REPORT 94-FIS-ll. The Federal

Infrastructure Strategy Program. U.S. Army Corps of Engineers, Water Resources Support Center, Institute

for Water Resources, 1994.

4. Jiang Z, Ponniah J, Cascante G. Improved ultrasonic pulse velocity technique for bituminous material

characterization. Proceedings of Assessment and Rehabilitation of the Condition of Materials Session of the

2006 Annual Conference of the Transportation Association of Canada, September 17-20, 2006.

5. ASTM, Road and Paving Materials, Annual Book of ASTM Standards, Volume 04.03, Standard test method

for pulse velocity through concrete. ASTM C597-09, American Society for Testing and Materials, West

Conshohocken, USA, 2009.

6. Witczak M, Kaloush K, Pellinen T, El-Basyouny M, Von Quintus H. Simple performance test for superpave

mix design, NCHRP Report 465, Transport Research Board, Washington D.C., 2002.


62

7. Terzi S, Karasahin M, Gokova S, Tahta M, Morova N, Uzun I. Asphalt concrete stability estimation from

non-destructivetest methods with artificial neural networks. Neural Computing & Applications 2013; 23(3-

4): 989-997.

8. Arabani M, Kheiry P, Ferdowsi B. Use of ultrasonic pulse velocity (UPV) for assessment of HMA mixtures

behavior. IJST, Transactions of Civil Engineering 2012; 36(C1): 111-114.

9. Majhi D, Karmakar S, Roy T. Reliability of ultrasonic pulse velocity method for determining dynamic

modulus of asphalt mixtures. ICEMS 2016, Materials Today: Proceedings 4, 2017, pp. 9709-9712.

10. Goel A, Das A. Nondestructive testing of asphalt pavements for structural condition evaluation: state of

the art. Nondestructive Testing and Evaluation 2008, 23(2): 121-140.

11. Arabani M, Kheiry P, Ferdosi B. Laboratory evaluation of the effect of HMA mixt parameters on ultrasonic

pulse wave velocities. Road Materials and Pavement Design 2009; 10(1): 223-232.

12. Gudmarsson A. Laboratory seismic testing of asphalt concrete. Licentiate Thesis KTH Royal Institute of

Technology, School of Architecture and Built Environment, Department of Transport Science Division of

Highway and Railway Engineering, SE-100 44 Stockholm, 2012.

13. TDOT quality management of flexible pavement layers with seismic methods: Test methods. Texas

Department of Transportation and the Federal Highway Administration, Project Number 5-1735-01, 2006.

14. Abo-Qudais S, Suleiman A. Monitoring fatigue damage and crack healing by ultrasound wave velocity.

Nondestructive Testing and Evaluation 2005; 20(2): 125-145.

15. State Commission of Roads and Bridges SCRB, Standard Specification for Roads & Bridges, Ministry of

Housing & Construction, Iraq, 2003.

16. AASHTO, Standard specification for transportation materials and methods of sampling and testing,

American Association of State Highway and Transportation Officials, 14th Edition, Part II, Washington,

D.C., 2013.

17. BS 1881-203:1986-Testing concrete. Recommendations for measurement of velocity of ultrasonic pulses

in concrete, 1986.

18. Krautkrämer J, Krautkrämer H. Ultrasonic testing of materials, 4th Edition, Springer-Verlag, New York,

1990.

19. Sarsam S, Al-Raw A, Abdul Rahim A. Non-Destructive evaluation of roller compacted concrete pavement.

Proceedings of International scientific conference of Salahaddin University-Erbil (SU-ERBIL2011), October

18-20, 2011.

20. Sarsam SI, AL-Shujairy A. Assessing tensile and shear properties of recycled sustainable asphalt

pavement. Journal of Engineering 2015; 21(6): 146-161.

21. Tarefder RA, Yousefi SS. Laboratory evaluation of moisture damage in asphalt. Canadian Journal of Civil

Engineering 2012; 39(1): 104-115.

22. Sarsam SI, Alwan A. Properties of super pave asphalt concrete subjected to impact of moisture damage.

Journal of Engineering 2015; 21(1): 1-14.


63

23. Arabani M, Kheiry TP. Evaluating the use of ultrasonic pulse velocity test for determination dynamic elastic

modulus of HMA Mixtures, Asphalt institute of Iran, 3rd national Congress on Asphaltic Materials, Iran,

2006.

24. Birgisson B, Roque R, Page G. Ultrasonic pulse wave velocity test as a tool for monitoring changes in HMA

mixture integrity due to exposure to moisture, Annual Transportation Research Board Meeting,

Washington DC, 2003.

25. Arabani M, Kheiry TP. Characterizing engineering properties of asphalt concrete using UPV test,

international conference on advanced characterization of pavement and soil engineering materials,

Athens, 2007.

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