2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Gabriel Arce
Dr. Marwa Hassan, LSU (Presenter)
Dr. Tyson Rupnow
Engineered cementitious composites (ECC) are steady-state multiple cracking strain-hardening cementitious materials that significantly enhance ductility and tensile strength of traditional cement-based materials. This investigation focuses on the development of ECC utilizing locally available materials in the state of Louisiana. The influence of high contents of fly ash (up to 81% cement replacement) and low Polyvinyl Alcohol (PVA) fiber content (1.5% volume fraction) were investigated for cost-effectiveness of the composite. Compressive and third-point bending tests were conducted to characterize the mechanical properties of PVA-ECC mixes produced at different levels of matrix/interface tailoring. Experimental results demonstrated the feasibility of producing ECC exhibiting robust strain-hardening behavior with locally available materials in the state of Louisiana and low fiber content (1.5% volume fraction of PVA fibers). Furthermore, results suggested that increasing cement replacement with fly ash favored ductility of the composites. Yet, compressive, and flexural strength were reduced suggesting a trade-off between strength and ductility. Moreover, specimens with the highest cementitious matrix strength (specimens produced with the lowest fly ash content) did not exhibit strain-hardening behavior but a strain-softening performance similar to that of fiber reinforced concrete (FRC). Strain-softening behavior was attributed to an excessive matrix strength that did not allow the strength or energy criteria to be met.