Correlation between shear stress and strain measured on steel fiber reinforced concrete panels and walls

Abstract

Previous studies have reported that steel fibers increase concrete shear strength and energy dissipation capacity. Existing strength prediction models focus on Steel Fiber Reinforced Concrete (SFRC) beams since code requirements already allow steel fibers to increase shear strength in these structural elements. However, the advantages of the SFRC have stimulated the investigation of its use in concrete walls subjected to shear demands. Unfortunately, the shear behavior assessment in SFRC walls requires significant investment that is not accessible for all research studies. Diagonal tension tests on SFRC panels could result in a more economical and viable option. Still, the shear response of RC panels differs from that of walls because of the test setup and the loading protocol. This study aims to correlate the maximum shear stresses and displacements measured in SFRC walls and SFRC panels from a database that includes 20 diagonal tension tests on panels and 33 quasi-static cyclic tests on walls. The 20 panels tests include three monotonic and 17 quasi-static cyclic tests from two previous studies. The other 33 wall tests include six dynamic shake table tests and 27 cyclic quasi-static tests from 9 previous studies. The current study showed that the maximum shear stresses in SFRC panels are approximately 2.3 times greater than those in SFRC walls. Additionally, the displacements associated with the maximum shear stresses in SFRC panels were about six times less than those registered in SFRC walls. The differences are mainly because the walls are affected by flexural, shear sliding, and web shear stresses, and the panels are predominantly affected by shear forces. As a result, two correlation models for stresses and displacements of SFRC walls are proposed as an effective tool for research with limited resources to implement cyclic tests on SFRC walls. The study also proposed stiffness degradation values associated with limit states and performance levels in SFRC walls for low-rise housing.