Device with stirrup and for testing binding force of reinforcing steel bar and concrete

Abstract

The invention relates to a device with a stirrup and for testing binding force of a reinforcing steel bar and concrete. The device comprises a reinforcing steel bar, a cylindrical substrate PVC (Poly Vinyl Chloride) pipe, an internal round steel board, an external round steel board, a base PVC pipe, a framework, a stirrup, an adhesive tape and a thin wire. The external round steel board is fixedly connected with the bottom of the cylindrical substrate PVC pipe through the adhesive tape, so as to form a cylindrical barrel device; the base PVC pipe is arranged on a horizontal surface; the cylindrical barrel device is arranged on the base PVC pipe; the reinforcing steel bar passes through the external round steel board and the base PVC pipe in sequence, and reaches the horizontal surface; the stirrup is arranged in the cylindrical substrate PVC pipe; a circle center of the stirrup is consistent to the center of the cylindrical substrate PVC pipe; the framework is connected with the stirrup through the thin wire; and after concreting is completed, the internal round steel board is arranged inside the upper part of the internal route steel board, so as to perform center correction on the reinforcing steel bar. Compared with the prior art, the device provided by the invention has the advantages of being simple in manufacturing, high in precision, low in cost and the like.

Description

technical field [0001] The invention relates to the field of an experimental test device for the performance of civil engineering materials, in particular to a test device for the bonding force between steel bars and concrete with stirrups. Background technique [0002] Reinforced concrete structure is one of the most widely used structural forms in modern civil engineering structures. With the passage of structural service time and the erosion of the service environment, the materials continue to age, the structural performance degrades, and the service life decreases. The durability of reinforced concrete structures It has become a key issue for the sustainable development of buildings. A large number of studies have shown that there are many factors that affect the durability of reinforced concrete structures, such as steel corrosion, concrete freeze-thaw damage, and concrete alkali-aggregate reaction. The most important factor of deterioration. The bonding force between...

AI Technical Summary

Problems solved by technology

The bonding force between steel bars and concrete is the key factor to ensure their work together. Corrosion of steel bars in concrete reduces the mechanical properties of steel bars, destroys the interface bonding force between steel bars and concrete, and seriously reduces the safety and applicability of reinforced concrete structures. and durability, how to scientifically and effectively evaluate the degree of cohesion loss, domestic and foreign scholars have adopted various forms of specimens to carry out steel bar pull-out tests, the arrangement of steel bars in the concrete matrix and the position of stirrups are the most restrictive test measurements A CRITICAL FACTOR FOR ACCURACY AND SUCCESS

[0003] At present, there are two types of devices for testing the bonding force between steel bars and concrete: squares and cylinders, and squares are mostly made of wooden formwork. The wooden formwork is processed into squares of the same size, and then assembled. Under the condition of ensuring the overall strength of the square device, it is difficult to ensure the dimensional accuracy, and it is difficult to accurately fix the position of the steel bars. During the concrete vibration process, the formwork is easy to crack. The rectangular stirrups are fixed on the wooden formwork with iron wires, and the stirrups are prone to misalignment. Inclined, the thickness of the concrete cover varies greatly, so the experimental error is relatively large; cylindrical devices, steel and plastic cylindrical devices are used in domestic and foreign experiments, and the steel bars are fixed by hoisting and bottom embedding methods to ensure that the steel bars are in The center position of the cylinder

The hoisting method is to place the formwork equidistantly on the level ground, tie the steel bars to the cross bars respectively, and place the steel bars at the center of the formwork respectively. During the concrete pouring process, the formwork and the steel bars are prone to misalignment, and the test accuracy is relatively low. Poor, the stirrups are usually hoisted. Place parallel steel bars on the upper part of the cylindrical formwork and hoist the stirrups inside the formwork. It is also difficult to ensure the position of the stirrups; Process the round hole with the diameter of the steel bar, fix the steel bar in the round hole, then place the cylindrical formwork, pour the concrete, when the concrete is poured to the design position of the stirrup, put the circular stirrup in, and then continue to pour the concrete, and Vibration is performed, so it is difficult to ensure the center position of the steel bar, and the position of the stirrup is prone to misalignment and inclination, and the test error is large

According to the above analysis, the above experimental devices have the characteristics of complicated manufacturing steps, low test accuracy, and difficult practical application. Therefore, a device is needed to ensure that the steel bar is in the center of the cylindrical concrete and the stirrup can be accurately fixed at the designed position, and The experimental test has high precision and is easy to operate and apply to meet the current large-scale test test work

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