Device for testing binding force of reinforcing steel bar and concrete

Abstract

The invention relates to a device 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 and an adhesive tape. The external round steel board is fixedly connected with an outer wall at 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; and after concreting is completed, the internal round steel board passes through the reinforcing steel bar, and is arranged in the base PVC pipe, so as to correct a center position of 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. 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 steel bars an...

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 loss of cohesive force, scholars at home and abroad have taken various specimens to carry out the pull-out test of steel bars, and the cylindrical concrete matrix is ​​the most suitable test piece for the stress distribution around the steel bar, but how to Ensuring that the steel bars are vertically arranged in the concrete matrix is ​​a key factor that restricts the accuracy and success of the test measurement

[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 processed with wooden formwork, which is processed into squares of the same size and then assembled. Under the condition of the overall strength of the square device, it is difficult to ensure the dimensional accuracy, and it is difficult to fix the position of the steel bar accurately. During the concrete vibration process, the formwork is easy to crack, so the experimental error is relatively large; And the plastic cylindrical device, the steel bar is fixed by the hoisting method and the bottom embedding method to ensure that the steel bar is in the center of the cylinder

The hoisting method is to place the formwork equidistantly on the level ground, bind and fix the steel bars on the cross bars respectively, and place the steel bars respectively at the center of the formwork. Poor; the bottom embedding method uses thick wood as the base, and processes a round hole the size of the diameter of the steel bar on the thick wood, fixes the steel bar in the round hole, and then places the cylindrical formwork and pours concrete, also during the concrete pouring process , it is difficult to ensure the central position of the reinforcement

According to the above analysis, the above experimental devices all have the characteristics of complicated manufacturing steps, low test accuracy, and difficulty in practical application. Therefore, a device that ensures that the steel bar is in the center of the cylindrical concrete, has high experimental test accuracy, and is easy to operate and apply is needed. To meet the testing work of the current large-scale trial

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