Research On The Mesh Reinforcement Influence On The Post-bonded Rebars Method To Test The Strength Of Concrete Slab

The quality of concrete directly determine the performance of engineeringstructure. With the growing complexity of engineering structures, the concrete qualityinspection is becoming more important. There are mainly three kinds of concretequality inspection methods: rebound method, coring method and pullout method, Thispaper mainly researches the effect of mesh reinforcement on inspecting the strength ofconcrete slab with the post-bonded rebars method. The theory of this method is quitesimilar to the pull-out method except for the difference that the high-strength fast-setbonding agency is applied between anchorage bar and concrete. The bonding strengthof this agent can not only satisfy the pull-out test requirement, but also ensure that thedamage origins from pull-out force rather than unproper bonding of the anchorage.This method overcomes shortcomings nicely in the embedded pull-out test which hasa long inspection cycle and the post pull-out test which is complex to operate. Thus, itgives a new method, which is convenient and has academic guidance meaning, to thescene test method of cast-in-place concrete.The raw materials for the test is provided by the laboratory of School of CivilEngineering. There are two types of concrete slabs(C30and C45) which are designedand casted, six different mesh reinforcement cases (non-reinforced, C10@200、C10@150、C10@120、C10@100、C10@80) are considered in each type. Based onStandard for test method of mechanical properties on ordinary concreteGB/T50081-2002and Technical specification for inspection of concrete compressivestrength by rebound method JGJ/T23-2011, the main contributions of this paper arelisted as follows:1. Post-implanted rebar pullout test, rebound test and compressive test arecarried out toward the concrete slabs, take record of the relevant test data, observeand describe the destruction process of the post-bonded rebars pullout test.2. To compare test data and regression analysis, comparative analyze the impactof varied spaced mesh reinforcement on the pullout strength.3. To carry out the contrast rebound tests on top surface and side flank of theconcrete slab respectively. Due to the energy lost, the errors of the rebound result teston the top surface are increased. Verified the cause of Technical specification forinspecting of concrete compressive strength JGJ/T23-2011in the class member should not be used on the board surface rebound method, and lead to the anchorage of thisthesis post-bonded rebars method.4. Use finite element software ABAQUS for numerical simulation of reinforcedconcrete slab, to analyze the concrete internal stress-strain progress and to contrastthe impact of varied spaced mesh reinforcement on the test result of post-bondedrebars test. When the spacing of rebar less than or equal to100mm, the meshreinforcement will influence the failure surface, by increasing the ultimate pulloutstrength; when the spacing of the rebar more than or equal to120mm, the meshreinforcement has little influence on the failure surface due to the proper distancebetween mesh reinforcement and failure surface. By analyzing the concrete stresscondition around the failure surface, it is deemed that the failure surface is caused bythe tensile stress. As a result, there is a good agreement between the ABAQUSanalysis results and the field test results.