THE INFLUENCE ON THE PEAK LOAD OF PULL-OUT FORCE AND ITS DISPLACEMENT BY THE EQUIPMENT FOR THE PULL-OUT TESTING

摘要

Drilled-hole methods has beenadopted in order to estimate the compressive strengthof structural concrete. By the development of theexpanding drill in recent years, the anchor boltscould be involved by the expanding part.In this study, under the application of two post-anchoring methods that were carried out by using theexpanding drill. We considered the influence on thepeak load of pull-out force and its displacement bythe change of the bearing devices (bearing ring,tripod bearings) and diameter of them and deducedthe expression for estimating the compressive strength of structural concrete.As a test results,(1) Peak of pull-out force of 80mm diameter and 100mmdiameter with bearing ring is greater than other diameterwith bearing device because concrete deformation is boundto the bearing device. And stiffness area is great by this effect.(2) 150mm diameter and 300mm diameter with bearing deviceare born outside of the area of resisting pullout force. Andstiffness fall area is not formed great difference not toinfluenced the effect that concrete deformation is bound to the bearing device.(3) 100mm diameter with bearing ring is higher correlationbetween peak of pull-out force and compressive strength ofconcrete than other diameter with bearing device becausefracture area of 100mm diameter with ring is small and stable.