Improved Supplementary Cementitious Materials in Hybrid Fibre Reinforced Concrete

Abstract

As a part of the fundamental investigation to evaluate the compressive fatigue damage of ?ber-reinforced lightweight concrete using high-volume supplementary cementitious materials (SCMs), the stressestrain response of the concrete was examined under cyclic loading within maximum stress levels of 0.9, 0.8, and 0.75 f ’ and a minimum stress level ?xed at 0.1 f ’, where f ’ is the concrete compressive strength. To produce a high-volume SCM binder, 20% ?y ash and 50% ground granulated blast-furnace slag were used as a partial replacement for cement. Amorphous steel (AS) and polyvinyl acetate (PVA) ?bers were added individually or in combination considering their conventionally recommended volume fractions. The fatigue tests were carried out by controlling the load between two limits with a sinusoidal variation at a frequency of 1 Hz. Test results showed that PVA ?ber was preferable to AS ?ber in enhancing the fatigue life of HVS-LWC, whereas the fatigue damage of the PVA ?ber concrete was lower than that of the AS ?ber concrete. This trend was more notable under a higher maximum stress level. To improve the fatigue life and fatigue damage of concrete, hybridization of both ?bers rather than monolithic use is recommended.