Pull-out tests of a new hooked steel-GFRP composite connector in precast concrete sandwich panels

Abstract

A new hooked steel-GFRP composite connector was proposed for precast concrete sandwich panels. The new connector consisted of a steel core and glass fiber-reinforced polymer (GFRP) as outer covering layers processed by injection molding machines. It was intended to connect the inner and outside layers of precast concrete sandwich panels with high structural performance, low thermal conductivity and ease of installation. To investigate the anchoring capacity of the new connector in concrete, pull-out tests were carried out on total 9 test specimens. Experimental results were analysed including pull-out strength, failure pattern, load-slip curve and load-strain curve etc. Results show that all the test specimens fail with the pattern of pulling out of concrete cone. Slippages between the connectors and concrete remain negative when the specimens were damaged. Hook of the connector linking the intersection of reinforcing bars improve the pull-out capacity significantly. The pulling-out capacity of the new connectors increase with the increment of concrete strength grade; and the average pulling-out capacity of the connectors become more than 5 times pulling-out load required by the Chinese code.