Behavior of Laced Reinforced Concrete Beam under Static Load


Laced Reinforced Concrete T-beams which are used inclined continuous reinforcement of two layers on each side of the beam have been studied in this research. The inclination angles of lacing reinforcement with respect to the longitudinal reinforcement are 45o and 60o respectively. Laced Reinforced Concrete T-beams of cross sectional dimensions (300mm * 80mm) flange and (150mm * 220mm) web have been used. Results have shown that specimens with lacing reinforcement are more ductile than beams without lacing ( conventional vertical stirrups) and the ductility factor of laced reinforced beams ranges from 1.94 to 9.44, while it is 1.46 for unlaced ( stirrups) beams. Also, the support rotation of laced reinforced concrete beams are about six times higher than that of conventional reinforcement. It has been shown that the lacing reinforcement of 60o inclination angle with respect to longitudinal reinforcement has more stiffness i.e. less deflection than lacing reinforcement of 45o inclination angle with respect to longitudinal reinforcement, while the strength capacity of the first type above is about 14% more than that of 45o inclination angle. The study of effect of diameter size of lacing reinforcement shows that lacing reinforcement of 8mm diameter has less deflection about 15% than that of 6mm diameter, also the ultimate load of first type above is more about 3% than other type. The results show that beams with lacing reinforcement are stiffer than beams with conventional stirrup reinforcement.