The influence of water content on the optimum combination of micro surfacing mixture

Abstract

ABSTRACT In this study, the effect of initial water (IW) on the performance of the micro surfacing mixtures was evaluated. For this purpose, the wet stripping test, wet cohesion test, wet track abrasion test (WTAT), sand adhesion and lateral displacement by load wheel test (LWT) were conducted on the mixtures containing different water contents and aggregate types. It was indicated that the aggregate type affects the mix design and the sensitivity of the WTAT test to the water content of the mixture. The best water content in the WTAT test varied for different aggregate types. For some aggregate types, the best WTAT results occurred when their water content was 0.5% higher than the optimum initial water content (OWC), obtained based on TB 113, while for some other aggregate types, the OWC+0.5% resulted in the best WTAT results. The samples whose water content is 1% more or less than the OWC had lower adhesion resistance in the wet cohesion test than the samples containing OWC and OWC±0.5%. In brief, using excessive water content has an adverse impact on the performance of the mixtures. On the other hand, insufficient water content also results in a decline in the performance of the mixtures.