Experimental Investigation On Pullout Behavior Of Embedded Steel

In recent years, as economic development and the development of structure engineering,Embedded reinforcement has been widely used in the tunnel engineering, masonry structure and glass curtain wall. The affect factors of the bonding properties is very complex and it affects project quality, so, it is important to make a further study of bonding between embedded steel bars and surrounding medium.Paper based on theoretical analysis and laboratory test, make a systematic study of the mechanism between reinforced and ambient medium. Make an all-round analysis about its breach of the mechanism. Made some significant achievements:1. Establish a embedded steel hyperbola destruction model in theoretically. Determined cohesive force and shaft force's calculated value. Verify the validity of data model with the experiment.2. Based on the test of loading curve-displacement. Summary of the embedded reinforced of drawing process can be divided into the five stages: slide smooth passage, snowflake smooth passage, cleavage passage, decline passage and remains passage, and then point out bonding slip of the characteristics of sound energy and loads moving synchronize changes in relationship with the emission testing technology. Further verify that the advance in drawing the reinforcement of the five destruction stages.3. According to the intensity of adhesion to the formula, point out influence the cohesive strength factors are anchorage length, anchorage diameter, surrounding medium strength. With the experiment data, use the least square method to curve fitting. Get the relationship between the cohesive strength and influence factors.4. In theory, we get the fixing length of the formula when Damage occurred in the heaving and mapping data validation. Arrive at use the bar diameter, characteristic value of strength of steel bar, sectional area of bar, tensile strength of concrete. When actual destruction happened, we can calculate the fixing length with four parameters.5. According to the actual destruction surface and using Mohr-Coulomb guidelines, derive the test strong formula of maximum condition. Compare the theoretical calculation the pressure on the strength of the surrounding medium in experiment. Arrive at in the applicable range can use actually pulls force to determine the strength of the surrounding medium.