Interface concrete and construction method

Abstract

An interfacial concrete comprises the following components in weight: water 1-1.5 parts, interface sealing agent for combining new and old concrete 7-9 parts, fine aggregates 2-3 parts, and coarse aggregates 10-14 parts. The components are mixed uniformly to obtain the interfacial concrete. The construction method comprises: pouring the interfacial concrete having the thickness of more than 50 cm on the surface of the old concrete; and pouring new concrete on the interfacial concrete. Through the above steps, the interface combining new and old concrete has high bonding strength and no cracks. Through the super retarding performance of the interfacial concrete with respect to the curing, in the stage when the new concrete is just poured and the volume changes dramatically, the harm to the bonding effect resulting from the deformation of the new concrete is eliminated by using the plastic state of the interfacial concrete. At the same time, a transition layer is formed between new and old concrete by taking advantage of the property that the performance of the interfacial concrete is between those of the new and old concrete, thereby reducing the deformation constrain between the new and old concrete, reducing the stress gradient at the joining parts of the new and old concrete, and improving the combining effect of the new and old concrete.

Description

technical field [0001] The invention relates to a material and a construction method used for bonding surfaces when pouring new concrete on old concrete of various buildings, in particular to an interface concrete and a construction method for improving the bonding strength of the new and old concrete bonding surfaces. Background technique [0002] Under the action of man-made and natural environment, a large number of buildings deteriorate every year and need to be repaired and reinforced. Many buildings also face the problem of reinforcement and renovation due to the change of environmental conditions and the extension of service life. . In the process of repairing, strengthening and transforming concrete structures, the bonding state of new and old concrete is the key to the quality of concrete structures after repairing, strengthening and transforming. There are differences in the construction process, and the adhesive must be used as the interface material in the const...

AI Technical Summary

Problems solved by technology

The joint surface adhesives commonly used in engineering mainly include cement slurry, expansion cement slurry, epoxy glue, etc. However, the use of such interface agents to repair or reinforce new and old concrete has low bond strength, poor corrosion resistance, and poor durability. Some interface agents Toxic to people and the environment, will cause harm to human health and pollute the environment

[0003] Chinese patent "200710051814.8" provides a "new-old concrete bonding interface sealant", which can be applied to the bonding of new and old concrete bonding interfaces, and provides a method of use for painting 1-3mm on the old concrete surface The new and old concrete is combined with the interface sealant slurry, and then new concrete is covered on it; the problems that still exist after using the sealant are: 1. Due to the thin thickness of the new and old concrete joint interface sealant slurry, the new concrete Late shrinkage may cause rapid deformation and stress concentration at the bonding interface, thereby affecting the bond strength of the bonding interface; 2. The bonding agent between the new and old concrete becomes an interlayer with a large difference in mechanical properties from the new and old concrete; at the same time Due to the large difference in age and material between new and old concrete, their mechanical properties will inevitably have a large difference. When the structure is under load, the interlayer is likely to cause damage to the bonding performance due to stress concentration and large deformation differences.

Images