Sulfate Resistance and Hydration Products of Steam Cured GGBFS Blended Cement Mortar

摘要

To meet the requirements of building industrialization of construction, steam curing is widely used to produce concrete elements in factories in China. However, there are few reports relating to the properties of steam cured concrete under dry-wet cycle and sulfate attack. The performance of steam cured (80°C (176℉) for 7h) GGBFS blended cement mortar (20% cement is substituted by GGBFS) under sulfate attack and dry-wet cycle condition were investigated. Under dry-wet cycle, both steam cured and standard cured GGBFS mortar present worse sulfate resistance compared with those of pure cement mortar. However, early age steam curing improves the sulfate resistance of GGBFS mortar, but decreases the sulfate resistance of pure cement mortar. The formation of hemicar-bonate and C-A-S-H under steam curing seems to be beneficial for protecting against the sulfate attack of cement mortar, but the coarse pore structure caused by steam cuing is harmful to the sulfate resistance of cement mortar.