Study On Technology Of Reflective Cracking Resistance Of Composite Pavement Under Heavy Load Conditions

In recent years, with increasing axle load and traffic volume, the long-life structure of composite pavement has gradually been promoted. Composite Pavement not only has strong bearing capacity advantage of Cement Concrete Pavement, but also has flatness and driving comfort advantages of Asphalt Pavement. But it has a fatal flaw--reflective cracking problem. And it’s almost impossible to avoid in the life cycle. From previous experience, the reflective cracking of Composite Pavement can prevent and mitigate, though not completely eradicated.In view of this, the reflective cracking problem of new Composite Pavement was deeply studied. We intend to develop a new material that mainly used to Composite Pavement under heavy traffic conditions. In order to achieve targets, the paper analyzes the generation and propagation mechanism of reflective cracking first, mainly focused on the action of prevention and treatment about pavement cracks. Such as reinforcement effect, the role of stress absorption, thickness of asphalt overlay and the way of paving asphalt surface. Secondly, MTS fatigue loading test and rolling load test were designed to evaluate reflective cracking resistance of paving asphalt surface directly, fiberglass grating, fiberglass-polyester cloth, warp knitting fiberglass-polyester paving mat, waterproofing membrane of SBS, road crack paste YN-25, road crack paste YN-50, anti-system of HZ/ZD-4 and galvanized wire. Mechanism of each material was deeply analyzed through test results. And they were sorted according to the performance of reflective cracking resistance. Thirdly, this paper proposes a new structure of double effects on reflective cracking resistance, and its performance was profoundly researched with different paving ways. At last, strong-reinforced materials and stress absorbing materials were selected to compound a new material which used to heavy traffic conditions. Reflective cracking resistance of the new material was proved through indoor tests. And its Construction Quality Control was also studied.The results show the following conclusions.(Ⅰ)Taking final loading times as the evaluation criteria, the reflective cracking resistance of eight materials were sorted in galvanized wire, anti-system of HZ/ZD-4, road crack paste YN-50, road crack paste YN-25, warp knitting fiberglass-polyester paving mat, waterproofing membrane of SBS, fiberglass-polyester cloth, fiberglass grating and paving asphalt surface directly. The key factors of preventing reflective cracking are reinforcement effect and stress absorption effect,and it should be a priority to choose strong reinforcement material especially in heavy traffic conditions.(Ⅱ)The reflective cracking resistance of the new composite material is significant. Three functions of “strong reinforcement, stress absorption, waterproof” were set in one. Materials of strong-reinforced(recommended using stainless steel mesh) play an important role in reflective cracking resistance which stress absorbing materials protect strong-reinforced materials not to be corroded and plays a role in stress absorption and facilitating construction.(Ⅲ)When selecting polyurethane glue or epoxy glue as adhesive material between the new material and cement board, it has good adhesive properties and the construction can be done at room temperature.(Ⅳ)The new composite material is cost-effective. It will have a good application prospect because it has a significant social and economic benefit.