Tensile Strength Improvement of Concrete Slabs Using Polyurea Spray

Abstract

Ductility is a desirable trait in an otherwise brittle concrete which is conventionally achieved via methods like introduction of steel reinforcement. While thin spray-on liner (TSL) is a material used in underground support systems to enhance the strength and ductility of rock and shotcrete, its application in concrete is a promising prospect. The study in this paper was conducted to observe the effect of application of Polyurea TSL on the flexural properties of unreinforced and lightly reinforced concrete slabs of varying strengths applied with varying thicknesses of Polyurea. The study used three-point flexural tests on slabs of uniform dimensions, simply supported on all sides, until failure or limit of test setup. Deflection was measured underneath the slab midpoint via a linear displacement sensor. Comparative analysis indicated that for the same strength and steel reinforcement, Polyurea application was significantly associated with an increase in stiffness, peak load, yield load, ductility, and energy dissipation in the specimens. Increasing Polyurea thickness also produced the same trend in the observed parameters.