Engineered Cementitious Composites for Improved Crack-Width Control of FRC Beams -A Review

摘要

Although, concrete has proven its performance in resisting compressive loads as a construction material, its increased brittleness and tendency to crack under small tensile forces and the lack of ductility of un-reinforced concrete elements has led to the development of new cementitious materials that address these limitations. Even though the introduction of short fibers in concrete (leading to Fiber Reinforced Concrete, FRC) has somewhat addressed the performance deficiency of this material under tensile forces, the FRC material itself was shown to soften in tension, leading to the continuous opening of cracks once formed. In response, high performance fiber reinforced cementitious composites such as Engineered Cementitious Composites (ECCs) have been introduced in recent years as an alternative to ordinary concrete and FRC in applications requiring crack width control, high ductility, high energy absorption, and damage tolerance. The use of ECC (instead of FRC) in these applications leads to the development of cracks that tend to spread all over the loaded element due to its strain-hardening property under sustained tensile stresses, a feature that is seen mostly in ductile metals. This paper presents a review of the effectiveness of ECC in controlling the crack width and crack growth in various reinforced concrete elements.