Testing method for testing steel bar-concrete bonding and slipping performance

Abstract

The invention discloses a testing method for testing steel bar-concrete bonding and slipping performance. The testing method comprises the following steps: carrying out a testing design according to astress moment theory; determining a loading method, a section size of a test piece and a production method of the test piece; determining a load-deflection curve and calculating steel bar slipping strain, bonding stress, maximum slipping amount and bonding strength; then identifying a damage mode and processing a testing result. According to the testing method, measured bonding-slipping characteristic parameters eliminate influences, caused by various factors of the testing method, on the testing result; the bonding strength is close to the tensile strength of concrete; the testing method hasgood repeatability and stability. The testing method can be used for researching the bonding and slipping performance of concrete with different types and different strengths, and steel bar-concretewith different types; the testing cost is low and the testing precision is high; abundant results are obtained, and the testing method has a remarkable effect on structure analysis, design and new finding of steel reinforced concrete.

Description

technical field [0001] The invention belongs to the technical field of performance testing of reinforced concrete structures, and in particular relates to a test method for testing the bond-slip performance of reinforced concrete. Background technique [0002] The bond-slip behavior of steel-concrete is an important performance parameter in the analysis and design of reinforced concrete structures. At present, the test methods for determining the bond-slip performance of steel bars and concrete mainly include the direct pull-out test method and the beam-type specimen test method. The direct pulling test is easily affected by the end pressure of the concrete specimen and concrete cracking. It needs to use short-buried specimens and configure spiral stirrups. The measured ultimate bond strength is high and discrete, and is not suitable for deformed steel bars and Determination of the bonding strength between high-strength concrete; the pull-out test of the beam specimen is mo...

AI Technical Summary

Problems solved by technology

The direct pulling test is easily affected by the end pressure of the concrete specimen and concrete cracking. It needs to use short-buried specimens and configure spiral stirrups. The measured ultimate bond strength is high and discrete, and is not suitable for deformed steel bars and Determination of the bonding strength between high-strength concrete; the pull-out test of the beam specimen is more in line with the stress condition of the interaction between steel and concrete, but the preparation and test process of the specimen are very complicated, not only the axial force and displacement test during the test process Difficult, the bond stress measurement also needs to embed the strain gauge in the steel bar, and calculate the bond stress indirectly through the strain

The influence of these complex factors makes the test results very discrete, and it is difficult to accurately obtain the bond-slip performance parameters of reinforced concrete, which affects the reliability of structural analysis and the safety of structural design.

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