Application Research On Cold Recycling Technique In Rehabilitation Project Of S345Zaozhuang-jining Highway

The growth of traffic and overloading vehicles lead to the increasing of roaddiseases, of which the pavement damage, especially the early damage is serious.Road construction steps into the development period in need of both constructionand maintenance. Considering the large amounts of rubble and waste produced bythe traditional grassroots maintenance approach, if the existing base material cannotbe fully used, the excavation and disposal of waste grassroots materials occupies theland and wastes human and material resources, part of which can also causeenvironmental pollution. The cold recycling grassroots technology can makeeffective use of waste base material, which improves the efficiency of waste, savesfare, and shortens the construction period. Therefore, relying on the project of S345Zaozhuang-Jining line overhaul, this paper conducts the following researches on therespects of overhaul program development, mix proportion design of coldregeneration grassroots, construction scheme and quality control technology and theanalysis of economic and social benefits:(1) Through the tests of pavement surface condition index (PCI), riding qualityindex (RQI), and pavement deflection of S345Zaozhuang-Jining line,comprehensive evaluation of road conditions and structural strength test results areconducted based on the testing results. Depending on the extent of the disease indifferent sections of the road, the overhaul and disease treatment program of S345Zaozhuang-Jining line is determined. Road sections with serious top grassrootsdamage but good condition in grass are selected for the grassroots cold recycling.(2) The performance requirements and influencing factors of cold recycled basemixture are discussed in detail; gradation of grass and cement milling performancetest results show that the performance of road base materials meets performancerequirements; based on the best moisture content and maximum dry density under different cement content, the impacts of the cement content on the unconfinedcompressive strength of the mixture of cold recycled base are analyzed to determinethe optimal dose of cement and present the best ratio of cold recycled mixture;finally, the mechanical properties of cold recycled base mixture with the optimumratio are tested and the results show that the strength and stiffness of cold recycledbase mixture meet the requirements of specifications and actual project.(3) Object to the cold recycled base construction of S345Zaozhuang-Jiningline, the corresponding construction process is put forward, and the dose of cement,degree of compaction, unconfined compressive strength as well as the thickness ofthe base construction are determined as the quality control indicators of the coldrecycled base. Engineering test results show: construction quality of the grass ofS345Zaozhuang-Jining line meets the requirements.