Continuously strong bridge structure with variable concrete density gradient

Abstract

The invention relates to a continuous rigid frame bridge structure with concrete density gradient changes. The upper structure of the bridge adopts three kinds of concrete materials, wherein: the base material in the mid-span adopts high-strength lightweight aggregate concrete with a dry apparent density not greater than 1950kg / m3 , in order to reduce the weight of the structure; the base material of the pier-beam consolidation is high-strength ordinary concrete with a dry apparent density of not less than 2300kg / m3 to meet the high compressive and cracking strength of the pier-beam consolidation; the mid-span and pier The base material of the main beam between the beam consolidation places adopts fiber-toughened and crack-resistant high-strength lightweight concrete with a dry apparent density of 1950kg / m3-2300kg / m3 to reduce the structural weight, improve the crack resistance of the concrete, and reduce shrinkage and creep. Negative Effects. The present invention can solve the technical problems of continuous rigid-frame span mid-span deflection and serious cracking of box girders through the optimized combination and matching of materials and structures and the optimized arrangement of prestressed beams.

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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