Ali Rahman

State-of-the-art review of interface bond testing devices for pavement layers: toward the standardization procedure

Abstract During the past thirty years, interface bonding between pavement layers has been a topical subject worldwide to research. In this context, many researchers have developed and utilized their own devices to investigate the properties of pavement interfaces. In the absence of an international standard procedure for interface bonding, it is inevitable that testing results are not comparable in all cases. In addition, various conducted studies reveal that parameters such as temperature, loading conditions, materials and so on exert an influence on interface properties. This paper aims to deal with the matter effectively via a thorough and comprehensive review of interface bond testing to lay the groundwork for standardization procedure. For this purpose, first, a general overview of interface bond function and its impact on pavement performance is presented. Then, different types of interface bond test methods according to loading conditions are explained; furthermore, the configuration of various setups is discussed and their function is compared together. Finally, given the prior experiences, a framework for a methodical approach to a standard evaluation of pavement interfaces is presented.

Analysis of measured strain response of asphalt pavements and relevant prediction models

Abstract In order to investigate the actual strain response of asphalt pavement under real condition, three types of asphalt pavement sections with typical surface structures are built. The effects of axle configuration, axle load, speed and testing temperature on strain response of asphalt pavement were analysed through in situ dynamic loading. Experimental results indicate that the strain response at the bottom of the asphalt surface layer increases with increasing axle load and temperature, but decreases with the rise of speed. On the other hand, the temperature exerts different influence levels on pavement sections with different structures. It is also concluded that the tandem axle load could lead to a greater strain response than that of single axle load. Applying the analysis of variance, the effects of pavement surface temperature, axle load, speed and their double interactions are studied as well. Finally, the paper proposes prediction models of the strain response at the bottom of asphalt layer by means of multivariate regression analysis.

Characterization of Interface Bonding in Asphalt Pavement Layers Based on Direct Shear Tests with Vertical Loading

AbstractThe interface bonding condition between asphalt concrete layers is unquestioned as one of the significant factors influencing pavement performance. In order to research the interface charac...

Experimental study of a new modified waterproof asphalt concrete and its performance on bridge deck

The employment of asphalt concrete on the bridge surface paving has been widely used in long-span bridges owing to its merits such as light weight, seamless, good performance and simple maintenance. Currently, three types of asphalt materials – namely Guss asphalt , stone mastic asphalt and epoxy asphalt concrete – are principally applied in bridge deck pavement. However, these asphalt pavements have their own disadvantages. In order to further enhance the overall performance of asphalt concrete and its engineering applicability on bridge surface, in this research a new modified waterproof asphalt concrete is produced. The new modified asphalt from two aspects of the asphalt binder material and mixture were developed. To evaluate the performance of the new asphalt material and verify the feasibility of its application, a series of tests on bitumen and asphalt mixture were conducted. In addition, a comparative evaluation between the newly developed asphalt mixture and traditional ones was conducted. All in all, the results of this research could make a great contribution to the application of asphalt concrete technology on bridge surface paving.

Using combined Avrami-Ozawa method to evaluate low-temperature reversible aging in asphalt binders

This paper aims to reasonably evaluate the reversible aging resistance of asphalt binders and comprehend the effects of low-temperature gradually hardening on fundamental properties of asphalt binders. To do so, extended bending beam rheometer (ExBBR) test with prolonged different conditioning times were performed on different kinds of asphalt binders, and viscoelastic mechanics model (Burgers model) was employed for describing the rheological properties. The combined Avrami-Ozawa equation was applied to characterise the non-isothermal crystallization process of asphalt binders which have a significantly different degree of physical hardening. The results showed that stiffness or m-value obtained from extended BBR test with logarithmic conditioning time has high coefficient of determination. Predicted stiffness and m-value from proposed empirical formula can be used to estimate extended BBR low temperature limiting grade (LTPG) that could be applicable for quality control (QC) purposes in the future. Lastly, the combined Avrami-Ozawa method can be successfully used to describe the non-isothermal crystallization process of asphalt binders used in this study.