Improving Moisture Susceptibility Of Asphalt Mixtures Using Lime And Other Additives

At present, moisture damage, the main pattern of early damage of asphalt pavement in our country, which has greatly influenced traffic capacity of road, safety traffic, effect of investment. Meanwhile, it causes directly and indirectly economic loss and negative social influence. With the further development of road construction, it's necessary to solve the problem of moisture susceptibility of asphalt mixtures, which is also the inevitable trend in construction of road. In rational foundation, it's very of great significance and urgeny to improve the quality and service performance of asphalt pavement, increase the life span, improve the traffic capacity, ensure the traffic safety, maintain effect of investment and society.This project, through a great amount experiments, systematically and quantificationally discuss the different methods by which additives, including hydrated lime, protland cement, and anti-stripping agent, improve various moisture susceptibility of asphalt mixtures,and also have been evaluated effectively. Results of test indicate that different additives can significantly improve the moisture susceptibility of asphalt mixtures, however, the optimum content of additives is different. The optimum content of hydrated lime and protland cement is about 1% and 2% respectively. Mineral aggregate is the most important factor to influence the moisture susceptibility of asphalt mixture while without additives, the granite is the worst which can't meet the specifications, the basalt is good which can meet the specifications in some cases, the limestone is the best which can meet the specifications all time. The different adding method of additives result various effects in the moisture susceptibility of the asphalt mixture, the slurry method is better than the dry method, however, there is no significant difference between the following two adding methods, joining to the cold aggregate and joining to the mixing machine with mineral filler. Limited data indicate that MS0 and TSR are in a relationship of 1:0.93 on average, that is the value of MS0 is larger than TSR. Inorganic additives is better than organic anti-stripping agent in terms of the effect of short and long term ageing.