Tragverhalten von Verbunddübeln unter zentrischer Belastung im ungerissenen Beton - Gruppenbefestigungen und Befestigungen am Bauteilrand [article]

Bernhard Lehr, Universität Stuttgart, Universität Stuttgart
Since about 30 years bonded anchors were used for fixing loads in concrete. In the last years the loadbearing and the load-displacement behavior and the design of the bonded anchors were investigated. About 1200 single bonded anchors and about 350 bonded anchor groups were tested. Three dimensional numerical analysis were performed with the program MASA. In the calculations four types of failure modes are obtained. The group effect can be clearly observed. With the critical spacings scr1 and
more » ... pacings scr1 and scr2 a model from FE-calculation is found. To control the FE-analysis a lot of experiments with quadruple bonded fastenings and bonded fastenings at the corner were performed. Several injection mortars were used. Single anchors with the same embedment depth like the quadruple fastenings were tested too. The model found from FE-calculations in relation of the anchor diameter is verified with these tests. If the diameter of the anchors is large and the bond strength of the mortar is high, the failure loads predicted according the model for bonded anchors will be higher than predicted according to the CC-method. Special quadruple tests with bonded anchors were carried out. It can be recognized, that the failure loads of these tests are lower than the failure loads according the model for bonded anchors. Therefore concrete cone failure must be checked. If the concrete cone failure load predicted by the CC-method is lower than the calculated value according the model for bonded anchors, this load will be correct. Fastenings with bonded anchors in thin concrete slabs are not discussed. The load bearing of bonded anchors in cracked concrete is not improved.
doi:10.18419/opus-170 fatcat:hdvf6oslt5gzzh2a6vx473qm7i