Research On Key Technologies Of Low-grade Highway Reconstruction And Extension Project In Chongqing Area

Many original low-grade highways in Chongqing area due to the narrow riding surface, lower traffic speed and other reasons, original low-grade Highway has been unable to meet the present transport demand. Therefore, low-grade highway reconstruction and extension project is imminent. By survey of low-grade pavement condition in Chongqing area, combined with application environment and design condition of WanLi Highway reconstruction and extension project, posing problems in WanLi Highway reconstruction and extension project and make a concrete technical research of each specific question.This paper focuses on specific projects, makes a research from the pavement diseases investigation and genetic analysis, pavement diseases treatment measures, research on pavement performance of asphalt concrete and pavement construction key technology, research. The purpose is offers good technical support and feasibility construction technology for backing project.Research indicates that:low-grade highway exists different pavement forms, which including cement concrete pavement and asphalt pavement, to a mostly cement concrete pavement one; in the reconstruction and extension project, for maximum using original pavement, can on original pavement for disease treatment, guarantee its using performance; on original concrete pavement which exists of pothole, cracking, and broken plate arch up subsidence some structure destructive disease needs plate treatment, then pave cement concrete again; original concrete pavement which exists of crack and pockmark apparent destructive disease such as reinforcement treatment measures can be taken; original asphalt pavement which exists of the pit and loose can take replacement treatment diseases.This paper carries indoor experiment based on practical engineering materials, including design of mineral aggregate gradation and determination of the asphalt mixture best asphalt aggregate ratio.For AC-20C, AC-13C asphalt mixture, modified bitumen asphalt mixture test results, this paper presented the applicable scope of the mineral aggregate gradation and the best asphalt aggregate ratio, and with SBS modified bitumen content proposed a scope for4%-6%.This paper concludes the key construction technology and the problems needing attention in the construction process of asphalt pavement in reconstruction and extension project, from raw material quality control, asphalt mixture production, asphalt pavement construction and quality control in the construction process on four aspects.