Fire resistance and thermal insulation properties of foamed concrete incorporating pulverized ceramics and mineral admixtures

Abstract

The effects of ceramics and mineral admixtures on thermal conductivity and fire resistance of foamed concrete were investigated in this study. The materials used for the study include: ordinary Portland cement, crushed ceramics, aluminum powder as foaming agent, river sand, plasticizer, and potable water. Ceramics were utilized as a particle replacement of river sand, while other materials were kept constant. In addition to physical property tests, the oxide composition and morphology of raw materials were studied using a Scanning Electron Microscopy (SEM) with Energy-Dispersive X-Ray Analysis (EDX). The workability of fresh-foamed concrete mixture was determined. Concrete specimens of 50 mm diameter × 150 mm height and 150 mm cubes were produced based on standard mix design, and they were used for the evaluation of thermal conductivity and fire resistance properties, respectively. Concrete specimens were cured by immersion in water for 28 days at a room temperature of 20 ± 1 °C. The concrete cubes were subjected to varying laboratory simulated temperature of 400, 500, and 600 °C, and both physical assessment and compressive strength of the cubes were subsequently assessed. SEM morphology and X-Ray Diffraction (mineralogy) of cured concrete were also obtained. Significant distress was noticed on concrete surface at 500–600 °C, evident by visible cracks development. A steady drop in compressive strength occurred as the furnace temperature rose from 400 to 600 °C. As compared to normal concrete, this study concludes that foamed concrete incorporating ceramics and mineral admixtures has a higher fire resistance.