The effect of ferrophosphorus aggregate on physical and mechanical properties of heavy-weight concrete

Abstract

The compressive strength of heavy-weight concrete specimens made with different percentages of ferrophosphorus and normal aggregates, steel powder, and Nano silica powder was examined. A series of 60 concrete specimens (dimensions of 150 × 150 × 150 mm) with different percentages of the mentioned materials were made and their compressive strength was measured at the concrete age of 28 days at the same loading velocities. After determining the compressive strength, the linear attenuation coefficient of the specimens was determined by radiation with gamma ray from a caesium-137 source. The results showed the most effective factors in increasing the compressive strength respectively were ferrophosphorus aggregates, Nano silica powder, and steel powder. The most effective factors in increasing the linear attenuation coefficient were ferrophosphorus aggregate, steel powder, and Nano silica powder, respectively. The highest compressive strength was obtained at the concrete age of 28 days by the specimen made with 100% ferrophosphorus, 20% steel powder, and 5% Nano silica and equaled 52(MPa). The lowest compressive strength was 25(MPa) obtained with 25% ferrophosphorus, 10% steel powder, and without Nano silica. Moreover, based on the results of the specimens’ linear attenuation coefficient test, the highest linear attenuation coefficient belonged to the specimens made with 100% ferrophosphorus, 30% steel powder, and 5% Nano silica and equaled 0.295, while the lowest linear attenuation coefficient was 0.1514 cm−1 obtained by the specimen made without ferrophosphorus and steel powder with 8% Nano silica.