Experimental Study Of The Bonding Performance Of Post-implantation Structures On Composite Concrete Substrates

Planting reinforcement is one of the most widely used reinforcement methods.In actual engineering,the beams,columns and other components that do not meet the requirements of bearing capacity need to be reinforced with enlarged cross-sections.For the composite concrete matrix post-reinforced structure that needs to increase the cross-section and then reinforce,different planting depths and rebars are required.The ratio of the length of the embedded lower base layer and the upper base layer will have a certain impact on the bearing capacity of the planted bar specimens.At present,most of the researches are on the failure mode and ultimate bearing capacity of the single-substrate implanted bar bonding and anchoring.There are few researches on the bonding and anchoring performance of the composite concrete matrix post-implanted bar structure.This article expands from the following three aspects the study:At present,most of the researches are on the failure mode and ultimate bearing capacity of the bonding and anchoring of ordinary reinforced concrete chemical planting bars,and there are few researches on the bonding and anchoring performance of the composite concrete matrix post planting bar structure.This article carries out research work from the following three aspects:Taking the embedded depth of the planting bar and the ratio of the length of the planting bar embedded in the concrete to the length of the embedded grouting material(length ratio coefficient)as parameters,14 composite concrete matrix planting bar anchoring specimens were designed.The pull-out test was conducted on 14 specimens of planted bar,the failure form and characteristics of each specimen were observed,the load-displacement curve of each specimen was measured,the change of pull-out bearing capacity of the planted bar structure under the influence of different parameters was studied,and the planting The effect of the bar depth and length ratio coefficient on the bonding and anchoring performance of the planted bar.The test shows that when the upper base of the composite concrete base material adopts a higher strength level(C60),the lower base level is C35,and the composite concrete matrix planted bar specimens are planted.When the depth is 4 to 9 d,compound failure generally occurs;under the same conditions as the diameter and depth of the reinforcement,the length ratio coefficient of the composite concrete matrix specimen is increased,and the corresponding peak load displacement increases accordingly,and the overall stiffness When the length ratio coefficient is 0.5,the ultimate bearing capacity of the composite concrete matrix implanted bar specimen increases with the increase of the implanted bar depth,because of the bonding between the two materials and the implanted bar glue There is little difference in strength,and the depth of the planted bar is still the most important factor that affects the ultimate bearing capacity of the planted bar.Analyzed the influencing factors of the composite concrete matrix planted bar,and established the composite failure calculation model of the composite concrete matrix planted bar based on the failure form of the composite concrete matrix planted bar pull-out test,and established the ultimate pull-out bearing capacity of the composite concrete matrix planted bar The calculation formula,the calculated value is in good agreement with the test value.Some specimens of this test were analyzed and verified by ABAQUS finite element software,and the simulated load-displacement curve was compared with the test load-displacement curve,and the agreement was good.This model is reasonable.And change the parameters on this model to study the influence of different parameters on the ultimate bearing capacity of the composite concrete matrix implanted bar.The analysis shows that: when the composite concrete matrix planting bar structure is compositely damaged,when the upper base layer strength level(C60)remains unchanged,the lower the base layer(concrete)strength level is higher,the adhesive strength between the glue and the base body is greater,and the drawing The load-bearing capacity is also greater;under the same conditions of other influencing factors,the pull-out load-bearing capacity increases with the increase of the length ratio coefficient.