SUPERSULFATED CEMENTS BASED ON VOLCANIC RAW MATERIALS

Author(s): K. Cabrera-Luna, E.E. Maldonado-Bandala, D. Nieves-Mendoza, J.I. Escalante García
Paper category: Proceedings
Book title: ICBBM 2017 Proceedings of the 2nd International Conference on Bio-Based Building Materials
Editor(s): Sofiane AMZIANE and Mohammed SONEBI
e-ISBN: 978-2-35158-192-6
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 234-238
Total Pages: 5
Language : English

Abstract: Research efforts worldwide have focused on developing alternative binders that would help to reduce the Greenhouse gas emissions associated to the production of Portland cement. Various raw materials, natural or byproducts, have been studied for the development of several types of binders. One of those greener cements are the so called supersulphated, which are commonly formulated using about 80% blast furnace slag and a source calcium sulphate and an alkaline activator that is commonly clinker of Portland cement. This paper presents results from an investigation on a novel supersulphated-type binder which contains at least 60% volcanic pumice; the sulphatic activators were hemihydrate and waste anhydrite, while the alkaline activator was portland cement (PC). The Taguchi method was used for the experimental design, which included variation in the composition of the binder and curing temperatures within the range of 20 to 60°C; a selection of 4 factors using 2 and 3 levels led to an orthogonal array L18 (21x33). The compressive strength was the response variable. After 28 days, the optimal composition showed 20.16MPa for a paste made of 70%pumice-20%PC-10%Anhydrite cured for 22 h at 60°C then at 20°C. In general, the pastes showed a trend towards higher strengths. The effect of higher curing temperatures and higher PC content were favorable for the strength. The microstructures showed that the pumice reacted although not very actively. Thermal analysis evidenced the formation of C-S-H, ettringite and gypsum. Some of mortars were cured under water and showed strength stability, which further evidenced the formation of C-S-H. A general discussion on the effects of the experimental parameters on strength and reaction products will be discussed

Online publication : 2017
Publication type : full_text
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