Cement-based composite material reinforced concrete interface shearing test device and test method

Abstract

The invention discloses a cement-based composite material reinforced concrete interface shearing test device. The device comprises reinforced old concrete, a cement-based composite material reinforcing layer sample, a base, a fixing mechanism, a loading mechanism and a supporting threaded rod, wherein the fixing mechanism comprises a movable front baffle plate and a fixed back baffle plate which are connected through a connecting threaded rod, and the old concrete is partially fixed on the base; the loading mechanism comprises a lifting type sliding rail, an orbit type sliding frame, a tension steel cable and a fixed pulley; the bottom of the orbit type sliding frame is level to the combining surface of the cement-based composite material reinforcing layer; the lifting type sliding rail is fixed on the supporting threaded rod in a free lifting way; the orbit type sliding frame can be fixed on the lifting type sliding rail in a sliding manner; the fixed pulley is fixed on one end of the lifting type sliding rail and is integrated with the orbit type sliding frame through the tension steel cable. The device disclosed by the invention is simple and easy to operate, convenient to assemble and test; the testing method based on the device can effectively determine the interface adhesive property of the cement-based composite material reinforced concrete structure.

Description

technical field [0001] The invention belongs to the technical field of building test equipment, and in particular relates to a cement-based composite material-reinforced concrete interface shear test device and method. Background technique [0002] Existing building structures are vulnerable to damage and deterioration after being subjected to long-term environmental and load effects. Reinforcement and repair of them can effectively guarantee the safety and use functions of the original structure. Using high-performance cement-based composite materials (such as fiber mesh, steel mesh-reinforced cement-based composite materials) to strengthen concrete structures is a new reinforcement method that is widely concerned in the field of reinforcement engineering. In this method, the reinforcement layer is usually a thin layer structure. This is conducive to maintaining the original structural cross-sectional size without increasing its own weight. [0003] Compared with the tradi...

AI Technical Summary

Problems solved by technology

Although it is relatively simple to use the above method to measure the interface shear strength, this method focuses on the bonding of the joint surfaces of two different materials, and does not directly consider the real stress of the actual reinforcement layer, different bond failure modes, and the reinforcement layer. The influence of factors such as medium reinforcement (fiber mesh or steel mesh) and thickness on the interfacial bond performance, which is particularly important for the effective application of high-performance cement-based composite materials to strengthen concrete structures

Although some researchers have configured simple "concave" or "convex" bases on the pressure testing machine, the concrete reinforcement specimens pasted with cement-based composite materials on both sides under the action of vertical pressure are in the concave or convex shape. The inside and outside of the base are staggered, and the double-sided shear test between the reinforced layer and the old concrete is completed, but the test results are controlled by the dimensional accuracy of the reinforced specimen when pouring, the construction quality of the reinforced layer on both sides, and the treatment of the joint surfaces on both sides The situation and loading eccentricity have a great influence. In the test, it is very easy for the reinforcement layer on one side to be debonded or destroyed first due to the uneven force of the reinforcement layer on both sides in the test, so that the interface resistance between the reinforcement layer and the old concrete cannot be accurately measured. shear strength

[0004] Therefore, for the bond performance test between the cement-based thin plate reinforcement layer and the original concrete interface, it is necessary to use a special shear test device to test the interface shear strength, but such test devices have not been reported yet

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