Study On Asphalt Pavement Structure Of Laibing To Mashan High Speed Concrete Bridge Deck

The operating conditions and the environment of bridge deck pavement are different from the common asphalt pavement.Currently,the project of concrete bridge deck asphalt pavement was relied on the experience or followed the main line design program due to the vague regulations in China,resulting in the earlier disease of bridge deck pavement.The operating condition of bridge deck pavement in Guangxi Laibing to Mashan expressway is harsh due to the high temperature and humid.Therefore,the concrete bridge asphalt pavement combination scheme and the setting of the waterproof adhesive layer are investigated,in order to avoid the serious disease bridge pavement in Guangxi Laibing to Mashan expressway.Firstly,the paper uses the indoor small-scale acceleration loading test system to simulate the effect of traffic load on the pavement structure and the complicated water and temperature conditions in Guangxi,by measuring the rut and depth of the different loading times to get the high temperature performance and anti-skid performance of the attenuation law.The results showed that:(1)The high temperature performance of the three pavement structures proposed in this paper is equal thickness structure>Flip structure>Straight structure,the maximum difference in rutting depth of the three structures after loading 600,000 times can reach 29.5%,which indicates that the high temperature performance of different pavement structures is very different;(2)The gradation type and the maximum nominal particle size have a great influence on the pendulum of the pavement,the initial value of the pendulum is mainly affected by the maximum nominal particle size,the attenuation level of the pendulum before and after loading is affected by the maximum nominal particle size and gradation type.In this paper,SMA-16 anti-skid performance is the best of the four kinds of surface layer.Secondly,the shear tests were carried out on the non-loaded specimen and the specimen after loading.The shear strength of the interface of different waterproof adhesive layers before and after loading was investigated.The results showed that:(1)This article selected the engraved groove,nap and the original three kinds of interface,the interface shear strength of the engraved groove is the largest,which is 30%higher than that of the original interface;(2)When the interface is the original interface,the interface shear strength of the synchronous gravel seal can reach more than twice that of SBS modified asphalt;(3)When the interface is the original interface,the maximum reductions of the interfacial shear strength of the synchronous gravel seal interface is only 7%before and after loading,the maximum reduction of the interfacial shear strength of the SBS modified asphalt is 40%before and after loading,which indicates that the simultaneous gravel seal can maintain the interface shear strength under the load.Finally,considering the convenience of the construction and the test results,the pavement of the test section is selected as follows:cement board engraved groove +synchronous gravel seal + 5cmAC-13C middle layer + 5cmAC-13C upper layer.In order to verify the feasibility of the program,relying on Guangxi Laibin to Mashan expressway construction project,built two bridge deck pavement test road,and carried out on-site road inspection,test results meet the specifications and program requirements.