The effect of limestone on the heat resistivity of high-strength lightweight foamed concrete

Abstract

Lightweight foamed concrete (LWFC) is typically a cementitious substance that includes a minimum of 20% (by volume) of mechanically restricted foam within the mortar blend. It has a higher pore content than conventional concrete. fifteen concrete mixtures were studied in this thesis. The first section included a reference mixture of cement, sand, water, fly ash, superplasticizer, and foaming agent in different proportions between (1-5) liter/m3 to obtain different densities ranging from (1520 - 1820). kg/m3 A compressive strength of 19.8 MPa has been obtained at 1680 kg/m3 density. The second section consists of a foaming agent of 3 liters/m3 with the reference mixture and limestone in proportions (10%-30%) replaced by sand. The specimens were cured with water. The third section consisted of the same components as the mixtures of the second section, but the specimens were cured with air. The Specimens were exposed to a temperature of 400 C° for six hours in an electric oven. The compressive strength of the reference mixture decreased after being exposed to a temperature of 400 C° by (10%-13%). As for the mixtures of the second part, the compressive strength of the samples increased by (2.5-3.5) after exposing them to a temperature of 400 C° for six hours. As for the mixtures of the third part, the compressive strength of the specimens increased by (5%-6%) after exposing them to a temperature of 400 C°.