Cement-based new and old concrete interface bonding strengthening material and preparation method thereof

Abstract

The invention discloses a cement-based new and old concrete interface bonding strengthening material and a preparation method thereof. The material is prepared by stirring Portland cement, a polycarboxylate high-performance superplasticizer, silica fume, I-grade fly ash, a micro-expansion agent, river sands and water. The material has the advantages of high initial fluidity, no water segregation under the action of a pressure, high bonding strength, excellent and stable tensile strength and compressive strength, good self-stability and strong penetrability of a slurry, abundant sources of rawmaterials, and simple preparation process. The material is mainly used for structure reinforcing engineering needing to improving the bonding strength between new concrete and original concrete by especially increasing the area of the cross section in the reinforced concrete structure reinforcement process, and can also be used as a grouting material for post-tensioned prestressed reinforced concrete.

Description

Technical field [0001] The invention relates to the technical field of building materials, in particular to a cement-based new and old concrete interface bonding strengthening material and a preparation method thereof. Background technique [0002] Reinforced concrete beams, columns, slabs in industrial and civil building structures, or secondary concrete structures in tunnel engineering, or in-service structures such as caps, pier columns, cap beams, and load-bearing beams in bridge engineering, should be designed and constructed For reasons such as insufficient strength, insufficient load-bearing capacity, cracking or even damage under overload, it is a normal state. When these phenomena are not serious, structural reinforcement is generally used for reinforcement, such as increasing the area of ​​the cross section. The bonding performance between the new composite layer concrete and the existing concrete is the key factor that restricts the reinforcement effect; in addition, f...

AI Technical Summary

Problems solved by technology

Currently commonly used bonding materials and grouting materials are either organic polymer materials or inorganic non-metallic materials, among which cement-based materials are the most important interface bonding materials or grouting materials. Their common characteristics are: relatively simple preparation, The sources of materials are wide, the compressive strength is not stable, bleeding is more likely to occur under pressure, organic polymer materials are more likely to oxidize and become brittle and cracked, the early strength development is slow, and the relative cost is relatively high, etc.