Evaluation of Bond Strength of Tack Coat Materials in Field

Mohammad, Louay N.; Bae, Abraham; Elseifi, Mostafa A.; Button, J W; Scherocman, J A

doi:10.3141/2126-01

Cited by 45 publications

(44 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Findings from NCHRP Project 09-40 using three surface texture conditions (open graded friction course [OGFC], sand mixture, and stone mastic asphalt [SMA]) found a pronounced effect of texture, with a spread in ISS of approximately 20 pounds per square inch (psi) between surface texture extremes and at relatively similar residual application rates to those used in this study ( 1 ). The field prepared specimens tested during the NCHRP study exhibited substantially lower ISS values for the same application rate and the same mixture materials ( 1 ). Further, results of NCHRP Project 9-40A demonstrated that the ISS values measured with test method AASHTO TP 114 correlated well with short-term cracking performance at six field sites with different climatic conditions and traffic levels ( 5 ).…”

mentioning

confidence: 59%

“…This was required because the test fixture cannot hold the two parts of the sample without confinement. It is worth noting that the same confinement pressures have been used in other ISS Studies ( 1 , 10 ). The shearing load in all cases was applied at a constant rate of 2.54 mm/min on the sample until failure.…”

Section: Methodsmentioning

confidence: 99%

“…Tack coats, when properly selected and applied, can be effective in preventing premature failure in the form of debonding, mat slippage, and potentially fatigue cracking, which may lead to reduced pavement life. Conversely, applying too heavy of a tack coat has been reported to result in low shear strength between adjacent layers ( 1 , 2 ).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Factors Affecting the Interlayer Shear Strength of Laboratory and Field Samples

Sufian

Swiertz

Bahia

et al. 2020

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

Asphalt emulsion is the most widely used tack coat material in the U.S. The objective of this study is to investigate factors that may affect the interlayer bond shear strength of asphalt emulsion tack coats of both laboratory and field compacted samples. The laboratory study included six types of tack coat materials applied on two surfaces with two residual application rates. The field study phase involved validation of the interlayer shear performance findings using field cores extracted from paving projects. The field study included taking cores of the existing layer, emulsions used for interlayer bonding, and loose mixes of new asphalt layers. Materials were collected to produce the laboratory prepared specimens for comparison with the field cores. Results of the laboratory study demonstrate that there is a direct relationship between the roughness (texture) of the existing surface and the interlayer shear strength (ISS) between two surfaces. Statistical analysis provided a strong correlation and indicated that 79% of the data variance can be explained with surface texture, emulsion type, application rate, and replicate effects. Comparing field cores with laboratory produced samples showed no clear relationship between the shear strength of laboratory and field specimens. It is speculated that the difference in compaction of the upper layers in the laboratory and field, and effect of shearing during coring of the samples from the field, resulted in higher laboratory shear values relative to field core values. The study highlights major challenges in using laboratory prepared samples to predict field behavior of tack coats.

show abstract

mentioning

confidence: 59%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Factors Affecting the Interlayer Shear Strength of Laboratory and Field Samples

Sufian

Swiertz

Bahia

et al. 2020

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

show abstract

“…Illustration of the aluminum slice between upper and lower layer of asphalt mixture. (2) Direct Shear Apparatus Direct shear tests were carried out to measure the interface shear strength between upper and lower layers of asphalt mixture under the conventional and the double-decked paving method[25,26]. As shown inFigure 4, the test apparatus (Yaxing Equipment of Civil Engineering Limited, Xi'an, China) consists of a shear box, a loading rod, a load cell and a motor.…”

mentioning

confidence: 99%

Interface Behavior of Asphalt Pavements Constructed by Conventional and Double-Decked Paving Methods

Gao

Shi

et al. 2020

Materials

View full text Add to dashboard Cite

Asphalt pavement consists of multiple layers of asphalt with a progressive decrease of nominal maximum aggregate size from the bottom to the top, which can be constructed by the double-decked or the conventional paving method (i.e., layer by layer). Reliable interface strength between the fine- and the coarse-grained layer of asphalt mixture is prerequisite to ensure the serviceability of the asphalt pavement. This study aims to compare the interface behavior of the asphalt pavement constructed by the conventional and the double-decked paving methods through laboratory and trial pavement tests. Laboratory test results show that the interface strength of the specimen prepared by the double-decked paving method is mainly contributed by the interlocking of the coarse- and the fine-grained asphalt mixture, fundamentally different from the conventional paving method, in which the interface strength is mainly provided by the tack coat oil. More importantly, the interface shear strength and the uniaxial tensile strength of specimens prepared by the double-decked paving method are about 1.5–1.8 times larger than that of specimens prepared by the conventional paving method. To verify the applicability of laboratory experimental findings to the practical engineering, a trial road was paved in situ using both double-decked and conventional paving methods. Cored specimens were collected from the trial road and their interface strengths are tested. Comparisons of the interface strength obtained from cored specimens further prove that the asphalt pavement constructed by the double-decked paving method has larger interface strength than that of the asphalt pavement constructed by the conventional paving method.

show abstract

“…The performance of thin lifts of HMA placed on top of existing pavements depends on the quality of the bond between new and existing surfaces. The shear strength developed by tack-coated interfaces has been shown to be temperature dependent ( 16 ). The shear and tensile strength of the bond provided by tack coats is one of the factors potentially leading to debonding issues and associated cracking.…”

mentioning

confidence: 99%

Temperature Measurements with Depth and Physical Evidence for the Effect of High Temperature Gradients on Top-Down Fatigue Cracking

Archilla

2020

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

This paper presents the results of pavement temperature measurements with depth over a year obtained with a setup emulating the heat flow on a pavement with 305 mm (12 in.) of hot mix asphalt (HMA) and 152 mm (6 in.) of aggregate base. Several findings related to top-down fatigue cracking (TDFC) in Hawaii were obtained from these measurements. It was observed that pavement temperatures near the surface, which were both the lowest and the highest in the HMA depending on the time of day, were rarely below 20°C, and thus, that most cracking in Hawaii occurs at higher temperatures. It was also observed that passing rains can cause sudden temperature drops of the order of 15°C within short periods (15 min). HMA moduli estimated using measured temperature profiles indicate that high temperature gradients may lead to inverted moduli profiles that when loaded cause the highest tensile and shear strains to occur near the surface, and that these may be a main reason for TDFC in the state. The simulated stresses and strains under high temperature gradients also indicate they may be conducive to delamination problems related to large horizontal shear strains generated near the surface and combined with nearly vertical but small tensile strains at the layer interface. The observation that cracking suddenly and consistently stops under overpass bridges and immediately resumes after them provides strong evidence consistent with the findings of the stress/strain distributions generated from profiles with high surface temperature and high temperature gradients potentially causing TDFC. The paper provides recommendations for further study.

show abstract

Evaluation of Bond Strength of Tack Coat Materials in Field

Cited by 45 publications

References 2 publications

Factors Affecting the Interlayer Shear Strength of Laboratory and Field Samples

Factors Affecting the Interlayer Shear Strength of Laboratory and Field Samples

Interface Behavior of Asphalt Pavements Constructed by Conventional and Double-Decked Paving Methods

Temperature Measurements with Depth and Physical Evidence for the Effect of High Temperature Gradients on Top-Down Fatigue Cracking

Contact Info

Product

Resources

About