Effect of Micronized Glass Fiber Additive on the Properties of Lightweight Aggregate Mortars

Abstract

This study investigates the effect of micronized glass fiber as a partial replacement for lightweight pumice aggregate on the physical and mechanical properties of cement-based mortars. A series of experimental mortars were prepared using Type I Portland cement, calcite, cellulose, and natural pumice, with the pumice gradually replaced by micronized glass fibers at ratios ranging from 5% to 40% by weight of cement. The samples were tested for density, compressive strength, and flexural strength according to the TS EN 998-1 standard. Results showed that fiber addition significantly improved the flexural strength, reaching an increase of 40.4% at 40% replacement, while compressive strength peaked at 25% replacement with a 48.5% increase compared to the control mortar. Density followed a similar trend, increasing up to 25% replacement and then slightly decreasing. These findings indicate that the optimal fiber content for balanced structural performance is around 25%, whereas higher dosages may be beneficial in applications where ductility and crack resistance are prioritized. The study highlights the potential of micronized glass fiber as a sustainable additive to enhance the performance of lightweight aggregate mortars.