Study On Fiber Strengthened Asphalt And Mixture Performance

Performance of the binder which can decide mixture is an important factor.So performance of fiber asphalt has important influence to the performance of mixture of fiber asphalt. It is of important significance that intensive studying on crack resistance at low temperature and stickiness at high temperature of fiber asphalt,analyzing the relation between the performance of fiber asphalt and the performance of mixture of fiber asphalt.The author summarizes the characteristic fiber asphalt cracking at Low temperature and gets bringing stress measuredvalue after stretching and crack test on the jumbo size fiber asphalt at low temperature. Then creates the mechanics model of tensile resistance of single fiber which been pulled out of the asphalt,and improve bridging stress of evenly distributed brief fibers in bridging stress formula computation space when asphalt cracking.The bridging stress measuredvalue calculated from the mechanical model and formula is fitting for bridging stress measuredvalue of fiber asphalt.This proves the rationality of the mechanical model and the formular. Relativity between bridging stress measuredvalue of fiber asphalt and crack resistance at low temperature of mixture is been finded out after greyrelation entropy of mixture through bending crack test at Low temperature. If the bridging stress measuredvalue of the used fiber asphalt is higher,the crack resistance at low temperature of mixture will be better.After analyzing the stickiness of fiber asphalt through tests, it can ben finded that wimble penetration test is fit for studying the stickiness offiber asphalt.Then analyze stickiness of fiber asphalt using shear strength value from wimble penetration test and propose a to be sensibility coefficient of shear strength. It is finded that it is interrelated between the index a, i3o℃from stickiness of fiber asphalt test and wheel rutting test result on mixture after greyrelation entropy of mixture wheel rutting test at high temperature.The dynamic stability of the mixture will be higher if using the fiber asphalt whose absolute value of a is less,or using the fiber asphalt whose shear strength t30℃is higher.The author designs the method on how to confect mixture of fiber asphalt to guarantee performance of fiber asphalt at low temperature or at high temperature. First crack resistance index at low temperature of fiber asphalt is the primary consideration to get the best constitute of fiber asphalt.At the same time stickiness at high temperature index should be considered.Then determine the dosage of the fiber asphalt after mixture testing.