Experimental study on performance of cold in-plant recycling of asphalt mixtures and its testing road

To save capital and sources and to protect environment, the waste and scrap of material is recycled. By in-door experiment of Marshall under vacuum and freeze thawing and testing rods, performance of cold in-plant recycling and asphalt mixtures was studied. Experimental results show that regenerant with a higher aryl and hydroxy has a good effect on recycling old asphalt mixtures, and the performance of recycling mixtures at high temperature is good. Their performance at low temperature can meet the requirements of low grade pavement, whereas, the moisture susceptibility of recycling mixture is poorer. It is also suggested that cement has a marked effect on improving the moisture susceptibility of recycling mixtures; cement is also useful for improving the performance at high temperatures. However, cement is unapparent for the performance at low temperature. Through the investigation on the testing road, it is proved that cold in-plant recycling mixtures is fit for the construction of low grade pavement, and when the proportion of new mixtures to old ones is 1:6 or 1:7, the final mixture has a good pavement performance. Moreover, the testing road paved by pure recycling mixtures has an acceptability performance as well.