Experimental studies on composite haunch beams

The paper is concerned with the behavior of steel–concrete composite haunch beams. Experiments were carried out to investigate the ultimate load behavior of haunch composite beams. Three continuous composite haunch beams were tested to failure. Two different proportions of slab reinforcements and two different haunch lengths were studied in order to examine the effects of these parameters on the ultimate load carrying capacity. Results obtained are presented in the form of load–deflection plots and different failure modes. It is found that through proper design and detailing optimum design of composite haunch beam can be achieved when plastic hinge occurs at haunch toes followed by a hinge at the mid-span to form a plastic collapse mechanism. Experimental results show that composite haunch beam exhibits a ductile moment–rotation behavior and is able to redistribute moment to the mid-span by loss of stiffness due to cracking of concrete slab and yielding of either steel reinforcement or cross section.

► Ultimate load behavior of steel–concrete composite haunch beams has been studied.
► Full scale tests were carried out on composite haunch beams.
► Slab reinforcement and haunch size varied to examine the effects of such variations.
► Results are presented in the form of load–deflection plots and failure modes.
► Ductile behavior and redistribution of moment to the mid-span are observed.