Research On Treatment Technology For Void Beneath Cement Concrete Slab Based On Preventive Maintenance

Due to the stiffness and stability of concrete slabs, cement concrete pavement has been widely applied in highway engineering. However, as the cracked slab is difficult to deal with, how to avoid or postpone cracking is significant to cement concrete pavement. Therefore, preventive maintenance is more pressing to cement pavement than asphalt pavement. In this paper, the main content of preventive maintenance of cement pavement were analyzed first, and then standard of preventive maintenance of cement pavement was established on this basis. Finally, in view of shortcomings of conventional maintenance measures, polyurethane grouting was proposed as a new preventive maintenance measure. Specifically, the main content of this paper is as follows:Firstly, the characteristic of preventive maintenance of cement pavement was analyzed. Based on the survey data of diseases of cement pavement, the relationship among diseases of cement pavement was studied using association analysis theory. According to the relationship among diseases of cement pavement, the main content of preventive maintenance of cement pavement was defined as the maintenance of void and faulting.Secondly, a field test was conducted in service area of expressway in Jiangsu Province, with the purpose of determining the criteria of void beneath cement concrete pavememt in service area of expressway, and its accuracy was verified by a pratical case. According to the result of pavement investigation, preventive maintenance standard of cement pavement was determined, and a decision tree for preventive maintenance of cement pavement was established subsequently. As one feature of preventive maintenance of cement pavement was the locality of maintenance area, preventive maintenance standard was divided into two parts:macro-criteria and specific criteria. Macro-criteria was use to determine the region of preventive maintenance, while specific criteria was designed for determining the specific slabs for preventive maintenance in the region.Lastly, according to the characteristic of polyurethane, polyurethane grouting was proposed as a new preventive maintenance measure. Then the field test was launched in service area of expressway, and the result was evaluated from three sides, the degree of faulting, deflection and the change of pavement structure obtained by ground penetrating radar (GPR). The overall construction technology of preventive maintenance measure based on polyurethane grouting was formed finally.