Mechanical Properties of Fiber-Reinforced High-Volume Fly-Ash-Based Cement Composite—A Long-Term Study

This article presents the long-term mechanical properties of a novel cement composite, no-aggregate concrete (NAC), containing 80% low-calcium (class F) fly ash (F-FA) and 20% ordinary Portland (OPC) without aggregates. The study investigates effect adding polypropylene fibers (PPFs) in varying volume fractions to NAC by conducting compressive, splitting tensile, flexural, bond strength, sorptivity tests, emphasizing morphological features over curing duration up three years. results indicate that PPF has an insignificant on compressive strength. However, strength improve with increasing fraction PPF. addition achieves ductile failure which is desirable. initial final water absorption rate (sorptivity) reduces Further, scanning electron microscopy (SEM) images reveal dense precipitation C-S-H, while energy-dispersive X-ray spectroscopy (EDS) quantifies hydration products. ultrasonic pulse velocity (UPV) affirms composite’s excellent quality.