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Substituting part of the cement with GGBS is a magnificent way to solve the problems of environmental pollution and resource consumption caused by cement manufacture. However, the use of high volume GGBS could retard the pozzolanic reaction at an early age due to their slow reactivity as the most important factor drawback in the properties of concrete. Thus, the improvement in the early strength could be achieved via an accelerated temperature of 60°C. Cement as a primary binder containing high volume GGBS was also prepared with RHA for property improvement of the Pozzolanic binders designed for high-strength cementitious concrete (HSC). The effects of increasing the amount of RHA pretreated as a replacement level of the primary binder with 5%, 10%, 15%, and 20%, with a constant amount of GGBS (50% of slag) on the hydration reaction were analyzed. The reaction products were characterized using X-ray diffraction analysis (XRD) analysis. The findings showed that cement containing no more than 50% GGBS exhibited the highest amount of CSH content than plain cement. The inclusion of RHA can successfully be used as a secondary source of SiO2 in cement containing high volume GGBS production. The main reaction products were calcium aluminate silicate hydrate (C-S-A-H) and hydrotalcite-like cementitious gels. The inclusion of highly reactive RHA into GGBS-OPC binders provides a synergistic effect that improves the properties of HSC, especially at later ages. [ABSTRACT FROM AUTHOR]

Making geopolymers from industrial waste such as calcinated local material like VA has not been fully developed. Some extensive studies are needed in this area to identify important aspects of achieving strength and resistance targets applicable to natural weather in Indonesia. Consider the strength and durability of a VA geopolymer mortar, for example. The curing technique applied in this investigation was a high temperature (550°C) curing period. This study's curing procedure comprised of a high-temperature curing duration (550°C) followed by compressive strength testing. The compressive strength of geopolymer concrete with calcination is higher than that of geopolymer concrete without calcination, according to this study. At 28 days of curing, the compressive strength of geopolymer concrete with calcination was up to 10% higher than that of geopolymer concrete without calcination, and at 45 days of curing, the compressive strength of geopolymer concrete with calcination was up to 15% higher than that of geopolymer concrete without calcination. [ABSTRACT FROM AUTHOR]