Continuously strong bridge structure with variable concrete density gradient

Abstract

The invention relates to a successive rigid-frame bridge structure with gradient variation of concrete density. The upper structure of the bridge uses three concrete materials, wherein, mid-span base material uses strong light aggregate concrete with dried apparent density of no more than 1950kg / m3 so as to reduce structure weight; the base material at the concretion position of a frusta and a beam uses strong common concrete with dried apparent density of no less than 2300kg / m3 so as to satisfy higher compression resistance and splitting resistance strength the concretion position of frusta and beam; the base material of primary beam between mid-span and the concretion position of frusta and beam uses strong light concrete of fiber toughening and splitting resistance with dried apparent density of 1950kg / m3-2300kg / m3 so as to reduce structure weight, improve concrete splitting resistance performance and reduce adverse impacts caused by constrict creep. The invention can handle the technical problem of serious cracking between the mid-span downwarp of successive rigid-frame bridge and a box girder through the optimized combining matching of the material and the structure and the collocating way of the optimized prestress bundle.

Description

technical field [0001] The invention relates to the field of bridges, in particular to a continuous rigid frame bridge structure with concrete density gradient changes. Background technique [0002] Long-span continuous rigid-frame bridges have a large number of constructions and have broad application prospects. However, more than 80% of the continuous rigid-frame bridges built in my country have various degrees of mid-span deflection and box girder cracking, which seriously affect the safety of bridge operation. Therefore, mid-span deflection and box girder cracking control technology have always been hot issues in the research of continuous rigid frame bridge construction. [0003] Since the 1980s, scholars at home and abroad have investigated and studied a large number of continuous rigid frame bridge diseases, and believed that the main causes of continuous rigid frame bridge span deflection and box girder cracking are: (1) The weight of ordinary concrete. Self-weight ...

AI Technical Summary

Problems solved by technology

High-strength lightweight aggregate concrete has large shrinkage and creep, low tensile strength, and oblique cracks still appear in the main beam between the mid-span of the bridge and the pier-beam consolidation; High maintenance cost; not only the maintenance cost is high, but also the mid-span deflection of the reinforced bridge and the cracking of the box girder cannot be effectively controlled, and the reinforcement technology cannot solve this problem

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