Implementation of natural and artificial materials in Portland cement

Abstract

For the preparation of modern cement and concrete, supplementary cementitious materials (SCM) have become essential ingredients. The technical, economic and environmental advantages of using SCM have become unquestionable. The main technical reasons for their use are the improvement of the workability of fresh concrete and durability of hardened concrete. Actually, SCM affect almost all concrete properties, while environmental and economic reasons may be more significant than technical reasons. These ingredients can reduce the amount of Portland cement used in cement composites, resulting in economic and environmental benefits. In addition, many of the SCM are industrial by-products, which can otherwise be considered as waste. This paper presents a literature review of the present knowledge on the impact of natural zeolite, waste construction brick and waste container glass on physical, chemical and mechanical properties of Portland cement as the most commonly used cement in the world.

Influence of Zinc-Saturated Zeolite on Portland Cement Hydration Kinetics

“…Comparing the results of the influence of natural zeolite and zeolite saturated with zinc on hydration, both curves retain a similar shape, which indicates that neither natural zeolite nor saturated zeolite affects main hydration mechanisms. In terms of decreasing the amount of heat released and the rate of heat release, saturated zeolite has a greater impact [11,28]. After mixing binder and water, a very sharp exothermic peak occurs due to the rapid dissolution of the clinker minerals and the rapid formation of ettringite and syngenite.…”

“…Once zeolite is saturated with heavy metals, it becomes a harmful waste itself and should be treated in a way that does not endanger the environment [9]. A practical method of disposing saturated zeolites is to dispose them in a cement matrix [10][11][12]. However, the e ect of zeolite saturated with heavy metals on the hydration process of Portland cement is still not clear.…”

Synthesis of novel chitosan/modified zeolite nanocomposites and their effect on the mechanical properties of cement mortars

“…Özsoy Özbay, A.U. Yazgan, Cement Wapno Beton, 26 (6) (2021), 531-544 doi: https://doi.org/10.32047/CWB.2021. 26.6.7 wodorotlenkiem wapnia, tworząc w procesie hydratacji dodatkowy żel C-S-H, co prowadzi do zagęszczonej mikrostruktury stwardniałego zaczynu (1,2).…”

“…W niektórych badaniach odnotowano negatywny wpływ zeolitu na wytrzymałość, szczególnie po przekroczeniu 10% udziału w zastąpieniu cementu, co przypisywano efektowi rozcieńczenia mieszanki cementowej, prowadzącemu do zmniejszenia ilości tworzącej się fazy C-S-H (3)(4)(5). Stwierdzono również, że dodanie zeolitu zwiększa zapotrzebowanie mieszanki na wodę, co prowadzi do zmniejszenia szybkości rozwoju wytrzymałości układów cementowych (6). W poprzednim badaniu, mimo że wytrzymałość na ściskanie betonu zawierającego zeolit była niższa niż próbek bez zeolitu, stwierdzono, że 10% zastąpienie zeolitu w betonie samozagęszczalnym o wysokiej wytrzymałości, było korzystne ze względu na lepszą odporność na penetrację chlorków, wykazując również akceptowalny poziom wytrzymałości (7).…”

“…In some of the studies, negative effects of zeolite on strength have been reported, particularly beyond 10% dosages of cement substitution, which was ascribed to the dilution effect on the blended cement, leading to a decrease in C-S-H formation (3)(4)(5). Also, the incorporation of zeolite was reported to increase the water demand of the mixture, leading to a decreased rate of strength development of the cementitious systems (6). In a previous study, even though the compressive strengths of concrete including zeolite, were lower than non-zeolite specimens, 10% of zeolite replacement in high strength self-compacting concrete was found to be benefi cial, due to the improved resistance to chloride penetration, also exhibiting an acceptable level of strength (7).…”