Low‐Carbon Composite Cement Mortar Incorporating Local Raw Materials as SCMs: Performance and Life Cycle Analysis

Abstract

Performance and life cycle analysis of composite cement mortars developed using local conventional (blast furnace slag and fly ash) and novel non-conventional (stone wool, glass wool, calcined Finnish clay, volcanic pozzolan Iceland, and ladle slag) raw materials as supplementary cementitious materials (SCMs) was investigated. The SCMs and the prepared mortars were characterized using x-ray diffraction, FTIR, TG-DTG, SEM-EDS, flowability, compressive strength, ultrasonic pulse velocity (UPV), water absorption, permeable porosity, and life cycle analysis (LCA). Experimental results showed a difference in the physical, chemical, and mineralogical composition of the SCMs, which in turn influenced the properties of the composite cement mortars developed. Ladle slag (30 wt.%) as SCM performed better, resulting in mortars with comparable mechanical, UPV, water absorption, permeable porosity, and microstructural properties but lower flowability values compared with reference mortars. In contrast, the use of other SCMs resulted in mortars with slightly lower mechanical properties, increased workability, and higher water absorption and permeable porosity than the reference mortars. The better performance of ladle slag may be attributed to the increased amount of precipitated hydration phases and formation of supplemental pore-filling hydration products, such as C3AH6 and Al (OH)3, attributed to the dissolution and participation of alumina from the SCM in gel formation. LCA results revealed a reduction in the environmental impact of the composite cement mortars (except those containing Finnish clay as SCM) when compared to PC-based mortars.