A method for treating the bonded surface of old and new concrete

Abstract

The invention discloses a treatment method for the bonding surface of fresh and old concrete. The method mainly comprises the following steps of uniformly spreading 80 to 150 kilograms dry gravels with particle sizes of 5 to 25mm into the surface of every cubic meter of self-compacting concrete instantly after the concrete is poured when the self-compacting concrete is produced, and performing standard maintenance on the self-compacting concrete, wherein the dry gravels are preferably spread in a way that a half of the gravels are sunken into the surface of the self-compacting concrete, the newly-spread gravels are free of deposition and contact; when fresh concrete is required to be poured, cleaning floating dust on the bonding surface of the old concrete at first, performing spraying wetting treatment on the bonding surface, removing explicit water on the surface of the bonding surface, dipping a brush in a common concrete interface agent, uniformly coating the surface of the bonding surface with the common concrete interface agent, and instantly pouring the fresh concrete; performing standard maintenance on the newly-poured concrete. According to the method, a later dabbing process of the surface of the old concrete can be reduced, damage to the surface of the old concrete can be avoided, the bonding performance of a concrete interface can be improved, and the construction progress can be accelerated.

Description

technical field [0001] The invention belongs to the technical field of concrete, in particular to a bonding method for new and old concrete. Background technique [0002] At present, the interface between the bridge deck pavement and the bridge deck is often damaged due to the poor bonding quality of the new and old concrete interface and the low shear force, which causes the bridge deck pavement to be damaged by interlayer movement. The roughness of the bonding surface of new and old concrete is one of the important factors affecting the bonding quality of new and old concrete. Researchers at home and abroad have done a lot of research on the treatment methods of new and old concrete bonding surfaces. Murray MA. et al reported in the title "Surface preparation for adhesives" (Concrete International 1989, No. 11, P69-71) that the high-pressure water jet technology was used to treat the new and old concrete bonding surfaces, with high work efficiency and remarkable results. ...

AI Technical Summary

Problems solved by technology

The acid etching method is to pickle the surface of the old concrete with a certain concentration of acid solution to improve the microscopic roughness of the old concrete surface, but the acid etching method will produce acid pollution, and some acid etching solutions contain chlorides, which will corrode the steel bars

Xu Ouming and others reported that the use of exposed stone bridge decks can significantly improve the stability of bridge deck pavement in the title "Study on Improving the Stability of Bridge Deck Pavement Structure with Exposed Stone Concrete" (Journal of Wuhan University of Technology, 2010, No. 01, P22-24). Structural stability, but exposed concrete requires complex and strict construction techniques, so it is not widely used in actual engineering