Behavior of hybrid-synthetic fiber reinforced cellular lightweight concrete under uniaxial tension - Experimental and analytical studies

This paper investigates the effect of hybrid-synthetic fiber reinforcement on uniaxial tension behavior of low strength cellular lightweight concrete (CLC). Low strength CLC material is increasingly used for structural and non-structural masonry applications. These masonry units of low compressive strength typically offer little resistance to tensile stresses under lateral loading resulting in the collapse of CLC walls. A unique experimental setup was developed to test CLC under uni-axial tension. Dog-bone CLC specimens of length 600 mm and 150 mm × 100 mm cross section (test region) were cast with different synthetic fiber dosages and tested under uni-axial tension. Digital Image Correlation (DIC) technique was used to understand the crack-bridging mechanisms of the fibers. Experimental surface strains and crack openings were inferred using DIC technique. Presence of fibers prevented the premature fracture and led to improved post-cracking stiffness and ductility. Restricted crack localization and improved ductility were also observed due to addition of fiber reinforcement. Analytical models were used to predict the behavior of fiber reinforced cellular lightweight concrete (FRCLC) in tension based on the matrix and fiber parameters. The predictions had a good correlation with the experimental results.