Cement is the binder at the base of one of the most important building materials, the concrete. Because of the large amounts involved in the global consumption, its production process is responsible for ingent quantities of CO2 emitted [1]. Nowadays, worldwide interest is becoming more and more focused in developing an eco-compatible cement and formulations based on reactive periclase (MgO) constitute one of the most promising emerging technologies [2]. In the presence of water, MgO/silicate mixtures hydrate and form a binder phase, M-S-H (magnesium silicate hydrate), a colloidal gel analogue to calcium silicate hydrate, C-S-H, present in traditional cements. A systematic study defining the relationship among composition, structure and properties of these binders is still lacking, but this knowledge is essential to optimize the properties of building materials and to modulate their perfomances to specific applications [3]. In this regard, the effect of mixing traditional cement and MgO-based eco-sustainable cement was evaluated. In this work, we considered the effect of changing percentages of Portland cement. The kinetics of hydration of the pastes prepared were monitored, as they give access to crucial informations for practical applications. Concurrently, pastes were characterized starting from molecular level up to the micro/macroscopic scale. The results show that both C-S-H and M-S-H gel phases have been obtained and the identification of the two binders confirm the idea that it could be possible to combine the ecological features of MgO-based cement with traditional cements. [1] Ellis M. Gartner and Donald E. Macphee. 2011. A physico-chemical basis for novel cementitious binders. Cement and Concrete Research 41: 736-749. [2] Stuart M Evans and Nikolas Vlasopoulos. 2010. Novacem: Carbon Negative Cement and the Green Cement Bond. [3] Francesca Ridi, Emiliano Fratini, Piero Baglioni. 2011. Cement: a two thousand year old nano- colloid. Journal of Colloid and Interface Science 357: 255-264. Acknowledgements: CSGI and FIR2013 (Project RBFR132WSM) for financial support.
Investigation of the structural properties of MgO-based eco-sustainable cements
Silvia Borsacchi;Marco Geppi
2015
Abstract
Cement is the binder at the base of one of the most important building materials, the concrete. Because of the large amounts involved in the global consumption, its production process is responsible for ingent quantities of CO2 emitted [1]. Nowadays, worldwide interest is becoming more and more focused in developing an eco-compatible cement and formulations based on reactive periclase (MgO) constitute one of the most promising emerging technologies [2]. In the presence of water, MgO/silicate mixtures hydrate and form a binder phase, M-S-H (magnesium silicate hydrate), a colloidal gel analogue to calcium silicate hydrate, C-S-H, present in traditional cements. A systematic study defining the relationship among composition, structure and properties of these binders is still lacking, but this knowledge is essential to optimize the properties of building materials and to modulate their perfomances to specific applications [3]. In this regard, the effect of mixing traditional cement and MgO-based eco-sustainable cement was evaluated. In this work, we considered the effect of changing percentages of Portland cement. The kinetics of hydration of the pastes prepared were monitored, as they give access to crucial informations for practical applications. Concurrently, pastes were characterized starting from molecular level up to the micro/macroscopic scale. The results show that both C-S-H and M-S-H gel phases have been obtained and the identification of the two binders confirm the idea that it could be possible to combine the ecological features of MgO-based cement with traditional cements. [1] Ellis M. Gartner and Donald E. Macphee. 2011. A physico-chemical basis for novel cementitious binders. Cement and Concrete Research 41: 736-749. [2] Stuart M Evans and Nikolas Vlasopoulos. 2010. Novacem: Carbon Negative Cement and the Green Cement Bond. [3] Francesca Ridi, Emiliano Fratini, Piero Baglioni. 2011. Cement: a two thousand year old nano- colloid. Journal of Colloid and Interface Science 357: 255-264. Acknowledgements: CSGI and FIR2013 (Project RBFR132WSM) for financial support.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
