Fiber sensor-based reinforced concrete bonding and slipping constitutive test method and device

Abstract

The invention discloses a fiber sensor-based reinforced concrete bonding and slipping constitutive test method and device. The device comprises a reinforcement steel bar, concrete, a fiber grating, adisplacement transferring device, a thin wire, a displacement meter, a displacement meter support, a drawing device and an anchoring tool, wherein a stress monitoring grating, a slipping monitoring grating and a temperature compensation grating are arranged on a fiber and are fixed in reinforcement steel bar groove holes by welding glass, two ends of the reinforcement steel bar extend out of the concrete, the displacement transferring device and the drawing device are respectively arranged at the two ends of the reinforcement steel bar, the displacement transferring device is connected with the displacement meter by the thin wire, local slipping quantity is measured by combining the slipping monitoring grating, the stress monitoring grating is used for measuring local bonding stress of thereinforcement steel bar, and the drawing device is used for drawing and loading. With the monitoring device and method provided by the invention, accurate test on a local bonding and slipping constitutive model between a long drawing test piece reinforcement steel bar and the concrete can be achieved, an error of a short drawing test piece caused by average stress and a slipping value is reduced,and particularly, accurate measurement of a curve a bonding and slipping reduction segment under large slipping can be achieved.

Description

technical field [0001] The invention relates to a bond-slip constitutive model test technology between steel bars and concrete, in particular to a high-precision test method for bond-slip constitutive tests between steel bars and concrete based on optical fiber grating sensing, and belongs to the field of civil engineering concrete structure performance testing. Background technique [0002] The effective bond between concrete and steel bar is the fundamental guarantee to realize the joint stress and coordinated deformation between the two, and the local bond-slip constitutive model is the basic index to characterize the bond performance between steel bar and concrete. In the design of reinforced concrete structures, finite element analysis, the design of anchorage length and lap length of steel bars, the calculation of deflection of flexural members, the calculation of crack width, and the calculation and analysis of joint slippage under earthquakes, it needs to be applied t...

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Problems solved by technology

[0003] There are still some problems in the test of the local bond-slip characteristics of steel bars and concrete: since the steel bars are wrapped in the concrete, there is no direct and effective way to test the local bond stress of the steel bars and the relative slip between the steel bars and the concrete

However, the above method also has some disadvantages: firstly, there is a relatively large approximation error when calculating the local slippage of the steel bar by using the continuous strain data and the slip measurement value of the drawn end of the steel bar, and the calculation formula is complicated, which is not easy to be widely promoted; secondly, The fragility and reliability of strain gauges will also directly affect the test results and accuracy

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