EXPERIMENTAL RESEARCH ON COLLAPSE RESISTANCE OF RC SPACE FRAME WITH SPECIALLY SHAPED COLUMNS

It is very important to understand the failure mechanism and alternative load paths for the collapse resistance design of a RC specially-shaped-column frame under accidental loading. The collapse tests were carried out for a 1/3-scale 2-story 3multiplied 2-bay reinforced concrete specially-shaped-column space-frame with a sudden side column removal or a sudden corner column removal. Then the test was carried out by a quasi-static load method. The test phenomena, crack distribution, failure process and load-displacement of a specially-shaped-column space frame was studied. The loading process of a specially-shaped-column space frame was analyzed. The transmission process of loading mechanism of the frame was analyzed. The results show that the dynamic effect is not significant to a RC specially-shaped-column frame. There is no pullout reinforcement. The cracks are mainly focus on the vertical member supports. The specially-shaped-column space frame experiences an elastic stage, an elastic-plastic stage, a plastic stage and a catenary stage during a side column test or a corner column test. The catenaries action in a side column is more obvious than that in a corner column. The reinforcement in a slab and a beam is very important to resist the collapse of a specially-shaped-column space frame.