Forced aging and ionic mobility of ternary cements exposed to aggressive saline marine environments and cryoclastic processes

Abstract

The most common supplementary cementitious materials used in concrete, in addition to Portland cement, are fly ash and silica fume; metakaolin, produced by controlled thermal treatment of kaolin, is also used in cementitious composites on account of its pozzolanic properties. This study forms part of an extensive research into the degradation of uncommercialized pozzolanic ternary Portland cement (TPC) exposed to different saline marine environments and cryoclastic processes. In marine environments, CSH gels from ordinary Portland cement fill the gaps between the grains and cover the surfaces. However, the porosity of ternary Portland cement is notably higher and permits the retention of ions. Cracking as a consequence of cryoclastic processes is found in the CSH gels and ettringite of ordinary Portland cement in continental climates. However, when ternary Portland cement is studied under similar conditions, the cracks are partially sealed by the gels without further rupturing due to the aforementioned processes.