Study On The Material Properties And Engineering Application For TLA Modified Asphalt

With increasing of national economy and modern highway transportation industry, the disease of the asphalt pavement is becoming more and more serious on account of traffic volume, traffic channelization,heavy loading and overloading. The requirement of asphalt pavement is becoming higher.Therefore,the modified asphalt technology has become the main means to improve the performance of asphalt and asphalt mixture and has been paid more and more attention.First of all, in order to ensure the quality of TLA modified asphalt, carries on performance test for the selected asphalt and TLA according to "Standard Test Methods of Bitumen and Bituminous Mixtures for Highway Engineering"(JTJ 052-2011) method. The effect of TLA on the common asphalt and its dosage have a close relationship, On the basis of the blending test, according to the TLA formula and the penetration of TLA modified bitumen, using the iterative method to calculate and determine the content of TLA. After the content of TLA has been determine, choosing 2 or 3 different dosages under the ranging from the content of TLA. Using the aggregate determined by engineering to mixing asphalt mixtures and evaluating the TLA modified asphalt pavement performance and construction performance, the final accurate dosage of TLA modified asphalt is 35%.Secondly, with the orthogonal experiment,the gradation range of surface layer(AC-13C) was optimizing the design. Taking 4 factors such as the passing rate of 0.075 mm, 2.36 mm, 4.75 mm, 9.5mm into consideration. at the same time, the gradation range of each sieve passing rates take lower, lower median, median, median and upper limit of 5 levels under the technical specifications; AS for TLA modified asphalt mixture AC-13 C type asphalt aggregate ratio factor,choosing the 5 level of 4.5%, 5%, 5.5%, 6% and 6.5%. With the methods of range analysis, the paper analyzed the effect casued by each factor such as stability, flow value, void, voids in mineral aggregate and asphalt saturation. The results show that: the passing rate of 2.36 mm is the key factor to the stability, flow value and f voids in mineral aggregate; asphalt aggregate ratio is a key factor to the porosity and saturation; 0.075 mm passing rate is the lowest influence to the stability, and the effect of 9.5mm passing rate to the flow value, void, voids in mineral aggregate and asphalt saturation is the smallest.Then making a comprehensive analysis of the result of the orthogonal test, carrying on the Marshall test according to the technical specification for construction of regulations.combined with the practical engineering experience for similar groups of indoor Marshall test to make the comparison of test results, select synthetic gradation which meet the technical requirements of current specification. According to the gradation gradation optimization, designing the surface layer(AC-13C) of TLA modified asphalt mixture. And through the Marshall test to determine the TLA modified asphalt mixture is 5.9%.According to "Technical specifications for Aonstruction of Highway Asphalt Pavement"(JTG F40-2004) to determine the surface layer of AC-20 C gradation range, combined with the practical engineering experience for similar groups of indoor Marshall test to get the best proportion is 4.8%.According to the "Technical Specifications for Construction of Highway Asphalt Pavement"(JTG F40-2004) regulations, the road performance of 35% dosage of TLA modified asphalt mixture AC-20 C and AC-13 C were analysised. According to the requirements of the asphalt mixture Technical Specification,the modified asphalt mixture’s high temperature stability, low temperature crack resistance, water stability, permeability coefficient, scattering Kentabao immersion test were examined, the test results show that the mixture ratio design meet the requirements of the specifications.Therefore, the researches such as ratio of mixture, road performance analysis and construction quality control standards for the TLA modified asphalt and its mixture provide the reasonable reference for the further applications of TLA modified asphalt and its mixture.