چكيده به لاتين
Abstract
Asphaltic mixtures with Stone Matrix Asphalt (SMA) are a sort of mixture of hot asphalt with coarse skeleton and high percentage of bitumen and filler. In Asphaltic mixtures, due to the high amount of bitumen and to prevent bitumen falling and to maintain the Coarse Gravel Structure the use of additives, such as fibers, polymer materials, and etc., is needed. A sample of these polymer additives is SBS which has a good performance to improve the properties of asphalt, but this polymer is an imported product and its high price has led to a limited use of it in the road construction industry of Iran.
In the present study, in order to prevent bitumen loss as well as to achieve an economical polymer composition, with the minimum functional properties of SBS in asphalt, a mixture of two domestic production low-priced polymers in the asphalt mixtures was used. In this regard, to improve bitumen consumption, 5% styrene-butadiene-styrene (SBS) polymer and polymer blends derived from polypropylene (PP) and styrene-butadiene rubber (Compounds 30/70, 50/50 and 70/30 of SBR/PP) have been used by 3, 4 and 5%, respectively.
In this research, to determine the optimum granularity and bitumen, the samples were made using Marshall Hammer, and for performance testing the prototypes have been constructed using rotational densities. Finally, Marshall Resistance tests, Resilient Modulus, Indirect Tensile Strength, and Dynamic Creep on the samples were performed. The results have shown that the combination of 50% of the polymers in the mixture has the best performance against moisture sensitivity and permanent deformation.
Key words: Stone Matrix Asphalt, Polymer Blends, SBS, PP, SBR.
