Effects of Light-Burnt Dolomite Incorporation on the Setting, Strength, and Drying Shrinkage of One-Part Alkali-Activated Slag Cement

Abstract

This study investigates the potential of light-burnt dolomite (LBD) as a supplementary cementitious material with ground granulated blast furnace slag (GGBFS) and Ordinary Portland cement (OPC). In this work, LBD was substituted for up to 20% of GGBFS in sodium sulfate-activated slag systems. The effects of LBD incorporation on the flow, setting time, compressive and flexural strength development, and drying shrinkage were explored with, X-ray diffraction and thermogravimetric analyses. LBD incorporation resulted in greater strength development of an alkali-activated slag system. The optimum LBD content for strength development was 10%, regardless of ordinary Portland cement content. In addition, LBD decreased the drying shrinkage, accelerated the hydration process, and induced hydrotalcite formation, which can be attributed to the reactive MgO inside LBD.

Strength, Shrinkage and Early Age Characteristics of One-Part Alkali-Activated Binders with High-Calcium Industrial Wastes, Solid Reagents and Fibers

“…The alkali cations present in the binding gels (C-S-H/C-A-S-H) of alkali-activated slag cements have been found to create instability in their stacks and thus have facilitated the collapsing of these gels, leading to additional autogenous shrinkage in drying conditions [28]. Jeon et al [29] reported that the formation of ettringite in GGBFS-based geopolymer binders counteracts shrinkage in GGBFS-based geopolymer binders effectively [29]. Research on low-calcium FA and bottom ash-based geopolymer concrete, a part of the mixing water, was found to remain associated with the binding gels (N-A-S-H/N-C-A-S-H) [30].…”

Evaluation of the Hydration Characteristics and Anti-Washout Resistance of Non-Dispersible Underwater Concrete with Nano-SiO2 and MgO

“…The isothermal calorimetry method is used to investigate the effects of temperature on the reaction kinetics of cementitious materials [ 40 ]. Figure 7 shows the calorimetric curves of heat release from the UWC specimens with (a) NS and (b) MgO.…”

“…The viscosity values of the UWC mixes with NS and MgO were assessed with a rheometer (Rheometer R/S Plus, Brookfield, WI, USA). To observe the setting time of the fresh UWC mixes, paste samples were obtained after mixing the UWC concrete, and the initial and final setting times were investigated using Vicat needles [ 39 , 40 ] according to ASTM C 191 [ 41 ].…”

Utilization of Waste Polysilicon Sludge in Concrete

“…Fresh properties i.e., air content and slump of the concrete mixes were examined. Paste specimens were made using a W/B ratio of 0.40 and investigated for heat flow using a semi-adiabatic calorimeter [30,31]. For Fourier transform infrared spectroscopy(FTIR) and XRD analyses, paste specimens were made using a W/B ratio of 0.4 and cured for 3, 7, and 28 days.…”