Eco-efficient Cementitious System Consisting of Belite-Ye’elimite-Ferrite Cement, Limestone Filler, and Silica Fume

Abstract

One of the main concerns in the modern cement industry is on reducing the CO2 emissions. As an alternative binder of Portland cement, belite-ye’elimite-ferrite (BYF) cement can reduce the CO2 emission by over 20% due to its benefits concerning the chemical composition and industrial processing. This paper proposed a ternary cementitious system consisting of BYF cement, limestone filler, and silica fume. The ternary system containing 10% limestone and 5% silica fume showed higher compressive strength than the BYF cement, while the CO2 emission factor further reduced by ∼13%. The effect of limestone and silica fume on the hydration was studied. It was found that the hydration reaction of limestone induced the formation of hemicarbonate and stabilized ettringite. This reaction formed dissolution rims around the limestone particles. At the early hydration ages, silica fume was bonded by aluminum hydroxide, forming aluminate silicate hydrate. During the hydration, the silicate dissolved and reacted with the hydration products in the dissolution rims of limestone. This reaction increased the Si content in the rims, and may potentially contribute to the compressive strength development of the ternary cementitious system.

CemGEMS – an easy-to-use web application for thermodynamic modeling of cementitious materials

“…The first paper on thermodynamic modelling applied to the hydration of CSA cements appeared in 2010 [44]. Since then, numerous studies used thermodynamic modelling to assess the hydration mechanisms of ye'elimite [40,[45][46][47][48], CSA cements [24,[49][50][51][52][53][54], blended systems with OPC [4,[55][56][57] or SCMs [58][59][60][61][62][63] and durability issues of CSA based systems [41,42,[64][65][66][67][68][69].…”

Understanding the sulfate attack of Portland cement–based materials exposed to applied electric fields: Mineralogical alteration and migration behavior of ionic species

“…The solid solutions of AFt and AFm were not considered. Siliceous hydrogarnet (C3AS0.8H4.4) and thaumasite usually form at slow kinetics at the ambient temperature [55,56]. The presence of electric fields does not significantly impact the slow formation kinetics of thaumasite [57], but it remains unknown whether the formation kinetics of C3AS0.8H4.4 will be influenced.…”

“…Almost no portlandite could be detected by 14 d, and the CaSO4 content remained almost constant afterward. Monocarbonate and hemicarbonate were observed due to the hydration of limestone [56,58]. These products had formed before the exposure to MgSO4 but started to decompose after the exposure.…”

Machine learning enables prompt prediction of hydration kinetics of multicomponent cementitious systems

“…Much of the research in the field, in the past several years, has been focused on designing, and optimizing the performance of, blended cementitious systems, which feature 10–60% mass replacement of cement with CO 2 -efficient mineral additives 1 – 4 ; so as to offset both carbon footprint and energy impact associated with cement production and concrete design-and-use 5 – 10 . Examples of the aforesaid mineral additives include: (1) Fillers: limestone (crystalline calcite: CaCO 3 ), and quartz (crystalline silica: SiO 2 ); and (2) Pozzolans: silica fume (amorphous silicate: SiO 2 ), and calcined clay such as metakaolin (dominantly amorphous Al 2 Si 2 O 7 ) 11 – 17 . When used to partially replace cement in concrete, fillers accelerate cement hydration rates 11 , 12 , 18 – 20 through provision of supplemental topographical sites for heterogenous nucleation of calcium silicate hydrate (C–S–H (In this manuscript, cement chemistry shorthand is used to represent cementitious compounds and the constituent oxides.…”