KnE Engineering
ISSN: 2518-6841
The latest conference proceedings on all fields of engineering.
Influence of Early Oven Curing on the Alkali Activated Binders with Reactive Magnesia Replacement
Published date: Apr 13 2020
Journal Title: KnE Engineering
Issue title: REMINE International Conference on Valorization of Mining and Industrial Wastes into Construction Materials By Alkali-activation
Pages: 207–214
Authors:
Abstract:
Magnesia is widely used an expansive agent in construction materials due to its delayed hydration, which will compensate for the thermal shrinkage. This study investigates the influence of magnesia and early oven curing on the mechanical performance and microstructures of alkali-activated natural clay samples under different curing regimes after 28 days. Microstructural analysis and pH measurements were conducted to assess the strength of the samples. Results indicate that the strength was greatly improved (in comparison with the control samples) by the incorporation of magnesia due to the formation of nesquehonite. Meanwhile, oven curing is an effective method in the fast strength development in alkali-activated natural clay. The results also demonstrated the possibility of CO2 curing in the strength development of the magnesia-modified alkali-activated natural clay.
Keywords: magnesia, natural clay, oven curing, compressive strength, microstructure
References:
[1] Kani, E.N., Allahverdi, A. and Provis, J.L. (2017). Calorimetric study of geopolymer binders based on natural pozzolan. Journal of Thermal Analysis and Calorimetry, vol. 127, pp. 2181-2190.
[2] Singh, M. and Garg, M. (2006). Reactive pozzolana from Indian clays—their use in cement mortars. Cement and Concrete Research, vol. 36, pp. 1903-1907.
[3] Gu, K., et al. (2015). Incorporation of reactive magnesia and quicklime in sustainable binders for soil stabilisation. Engineering Geology, vol. 195, pp. 53-62.
[4] Yi, Y., et al. (2016). Magnesia reactivity on activating efficacy for ground granulated blast furnace slag for soft clay stabilisation. Applied Clay Science, vol. 126, pp. 57-62.
[5] Jin, F. and Al-Tabbaa, A. (2014). Strength and hydration products of reactive MgO–silica pastes. Cement and Concrete Composites, vol. 52, pp. 27-33.
[6] Ruan, S. and Unluer, C. (2007). Influence of mix design on the carbonation, mechanical properties and microstructure of reactive MgO cement-based concrete. Cement and Concrete Composites, vol. 80, pp. 104-114.
[7] Neto, A.A.M., Cincotto, M.A., and Repette, W. (2008). Drying and autogenous shrinkage of pastes and mortars with activated slag cement. Cement and Concrete Research, vol. 38, pp. 565-574.
[8] Mo, L., Deng, M. and Tang, M. (2010). Effects of calcination condition on expansion property of MgO- type expansive agent used in cement-based materials. Cement and Concrete Research, vol. 40, pp. 437-446.
[9] Ruan, S. and Unluer, C. (2017). Effect of air entrainment on the performance of reactive MgO and PC mixes. Construction and Building Materials, vol.142, pp. 221-232.
[10] Ruan, S., et al. (2017). Performance and microstructure of calcined dolomite and reactive magnesia- based concrete samples. Journal of Materials in Civil Engineering, vol. 29, p. 04017236.