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

In Kyu Jeon,Hong Gi Kim,Sadam Hussain Jakhrani,Jae Suk Ryou

doi:10.3390/ma12182874

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.

Highlights

Ordinary Portland cement (OPC) is a common raw material for concrete structures.the cement manufacturing process is considered to be a major factor in global warming and air pollution because it emits a large amount of carbon dioxide [1]
For the OPC replacement levels, a reduction of OPC content in the mixture enhanced the ground granulated blast furnace slag (GGBFS) content and decreased the fluidity value, which is a similar trend to that seen in a previous paper [39,40]
OPC, GGBFS, and light-burnt dolomite (LBD) as binder materials, with solid sodium sulfate powder as the alkali activator. These experiments were conducted to investigate the effects of LBD incorporation on setting, strength, and drying shrinkage of an activated slag (AAS) system

Summary

Introduction

Ordinary Portland cement (OPC) is a common raw material for concrete structures. The cement manufacturing process is considered to be a major factor in global warming and air pollution because it emits a large amount of carbon dioxide [1]. In alkali-activated cement (AAC), all or part of the cement binder is replaced with supplementary cementitious materials (SCM); AAC is a potential eco-friendly alternative that can reduce carbon dioxide emissions [2,3]. AAC is generally obtained from two-part reactions with solid aluminosilicate precursors and concentrated aqueous alkali activators [4]. Recent studies have focused on the development of user-friendly one-part AAC, in which only water is added [7,8,9] Two-part reactive AAC with corrosive and viscous alkali activators, such as sodium silicate solution has high costs, due to handling and application problems [5,6].

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