Research On Slab Breaken Mechanism And Prevention Of Cement Concrete Pavement

In the paper the factors that may cause slab breaking of cement concrete pavement are analyzed thorougly and systematically. It is believed that slab breaking is closely related to material quality, material composition, concrete vibrating, curing, evironmental condition, joint sawing, construction competence and management of contractor and employer, and others. From analysing to in-situ experiments high slab breaking ratio is mainly caused by the following.1. Sawing time is improperly controlled, sawing time being too late;2. Water-cement ratio is inaccurately mntrolled, very serious in exceeding that as specified;3. Slab breaking induced by thermal stress;4. Incorrect curing methods are adopted. Curing with water spreading is not handled in time. With regard to the afore-mentioned problems, corresponding preventive measures, qulity control indices and site control approach are presented based on expeeriments and analysing worlx. Application in test roads has received prominent effects. The research work of this project is of great significance in actively improving the construction quality and decreasing the slab breaking ratio for cement concrete pavement construction in the province.Furthermore considering that cement concrete pavement is developing rapidly in the province and that we are soon facing with remedial and mantenance problems, detailed study was also performed on remedial and maintenance methods for broken slabs. Mix design, construction method and techological procedure for fast-setting concrete are proposed. The research findings will act as a guidance for repairing broken slabs of cement concrete pavements in the province.