An overview of moisture damage performance tests on asphalt mixtures

This paper presents a review of moisture damage performance tests on asphalt mixtures. The moisture damage remains to be a detriment to the durability of the Hot Mix Asphalt (HMA) pavement. Moisture damage can be defined in forms of adhesive failure between bitumen and aggregates and cohesive failure within bitumen. Aggregate mineralogy, bitumen characteristics and anti-stripping additive dominantly influence the performance of asphalt mixtures towards moisture damage alongside construction methods, climate and traffic loading. Various laboratory test methods have been developed to quantify the moisture damage performance of asphalt mixtures by resembles the action in the field, including qualitative test such as Boiling Water Test (ASTM D3625) and quantitative tests such as Modified Lottman Test (AASHTO T283). Both of these tests consist of two phases, which are conditioning and evaluation phase. This paper will review the effectiveness of the selected available tests based on various asphalt mixtures materials. Generally, this study indicates that asphalt mixtures consisted of limestone aggregates, modified bitumen and addition of anti-stripping additives will provide more resistant towards moisture damage

Sustainable pavement: a review on the usage of pavement as a mitigation strategy for UHI

Urban Heat Island (UHI) phenomenon is currently affecting many millions of people worldwide. The higher temperatures are experienced in urban areas as compared to the surrounding countryside. The UHI effect has been a great threat to human habitation, and the way to mitigate this problem has been a global concern over decades. Artificial and manmade pavements have been recognised as one of the major origins that deteriorate the thermal environments for living. On the one hand, commonly used pavement materials could lead to a reduced latent heat flux and an increased sensible heat flux to the environment. Following this, there is a series of experiments and numerical analysis that has been conducted by researchers. The selection of pavement type requires an understanding of a local context of an area and characteristics of the pavements. This current study emphasises on reviewing the features, factors and impacts of different type of pavements, as well as determining the suitability of different types of pavements. It is expected that the outcome from this study can assist in further understanding of pavements and its effects on UHI, as well as can ultimately assist in reducing the effect of UHI on human population