چكيده به لاتين
In recent decades, to improve the shelf life of asphalt surfaces and prevent breakdowns such as rutting, Moisture Susceptibility and fatigue, stone matrix asphalt mixtures (SMAs) with larger aggregates, bitumen and filler were designed. In recent years, due to increased service, traffic congestion, gear loads and low maintenance, road structures in Iran have deteriorated and therefore fail faster. In order to minimize asphalt breakdowns such as rutting, Moisture Susceptibility and fatigue, the use of stone matrix asphalt is justified and needs to be modified with suitable polymers. Styrene-butadiene-rubber and ethylene-vinyl-acetate polymers are known polymers to modify the properties of bitumen and eventually asphalt mixtures that improve the performance characteristics of the produced mixture at high and low temperatures. Therefore, the main objective of this experimental study is to evaluate the performance of SMA asphalt mixtures modified by SBR / EVA polymer blend as a polymer blend consisting of two polymers with elastomer and plastomer properties. In this study, dolomitic calcareous aggregates, bitumen with penetration of 85-100 mm, and "styrene-butadiene-rubber" and "ethylene-vinyl-acetate" as polymer additives, as well as the "styrene-butadiene-styrene" polymer additive were compared. 4% and 5% by weight of bitumen was used. Resilient modulus, indirect tensile strength, dynamic creep, and indirect tensile fatigue tests were performed on specimens to control rutting, Moisture Susceptibility and fatigue behavior of asphalt mixes. Experimental results show a better effect of the styrene-butadiene-rubber polymer additive at intermediate temperatures and the effectiveness of the ethylene-vinyl-acetate polymer additive at higher temperatures. It is also observed that the samples containing the polymer blend have in most cases had similar or near effects to the "styrene-butadiene-styrene" polymer additive as a thermoplastic elastomer polymer.
