Research On Performance Of Compound Rubber Modified Asphalt Mortar And Mixture

Asphalt-rubber and its mixture have unique advantages in reducing pavementthickness, extending lifetime of pavement, delaying reflection crack, decreasingtraffic noise and so on. To prepare the compound rubber powder modified asphaltmortar (A). A is solid bitumen mucilage, and it could be transported, stored and usedat room temperature. The Product was good to solve the problems of poor storagestability and large energy consumption. However, because of the special properties ofasphalt-rubber and the differences of environmental conditions, pavement materials,and pavement structures at home and abroad, demestic awareness of the performanceof compound rubber power modified asphalt and its mixture is very lacking. In orderto solving above problem,this paper will study on the performance of compoundrubber power modified asphalt and its mixture and it has important significance incompound rubber power modified asphalt’s application in highway engineering inChina.Firstly, by using IR and TGA, this paper analyzed the composition of A which isdeveloped by the X company. The results showed that A has good storage instabilityat room temperature, its inorganic composition accounted for about50%of the totalmass and the physical blending reaction is the dominate reaction in its modificationwith chemical reactions.Secondly by Brookfield revolving viscosity test and dynamic shear rheometertest, this paper test the rheological properties of A. The results show that,comparedwith SBS asphalt mortar, Pelltpave improved the asphalt’s high-temperature stabilityand low-temperature cracking resistance and significantly, and reduced thetemperature sensitivity of asphalt at the same time.Then this paper through the Marshall method to determined the mixture ratio andgrading. According to orthogonal tests to define the most suitable forming process ofdense-graded bituminous mixtures of A asphalt: heat the aggregate to200℃, andsets the mixing pot temperature to195℃, mix with A90s, then mix with the mineralpowder another90s, finally compact the mixture at170℃.Finally comparing the A asphalt’s high-temperature performance,low-temperature performance, water stability and dynamic modulus with the SBS asphalt mortar. The results show that its high temperature stability is weaker thanthe SBS asphalt mixture, and the low temperature crack resistance and water stabilityperformance is superior to the SBS asphalt mixture. By analyzing the dynamicmodulus of asphalt mixtures at different grading, temperature and load frequency, thispaper finds that the dynamic modulus of A asphalt mixture and SBS asphalt mixtureincreases with the increase of frequency (decrease of temperature). The dynamicmodulus of A is bigger than SBS’s in low and medium frequency high temperaturesection.And in high frequency low temperature section, the dynamic modulus of A issimilar with SBS’s. CAM model can describe the dynamic modulus master curvewell.