The influence of mineral additives on the strength and porosity of OPC mortar

Mercury intrusion porosimetry study was carried out on samples of ordinary Portland cement mortars made with mineral additives such as fly ash, granulated blast furnace slag, phosphorous furnace slag, limestone, and lime sludge. The total porosity and compressive strength of all the blended cement mortar samples were determined at 7, 28, and 90 days of hydration. The porosity and mean pore diameter were found to increase with the addition of fly ash and slags, although the total pore volume was almost the same. The strength was found to decrease with the increase in porosity, but the extent of decrease in strength was more closely related to slags and fly ash addition than to limestone and lime sludge. Acceleration of the strength development of ordinary Portland cement was also observed with limestone and lime sludge addition. (C) 2000 Elsevier Science Ltd. All rights reserved.