The Hydration and Volume Expansion Mechanisms of Modified Expansive Cements for Sustainable In-Situ Rock Fragmentation: A Review

Abstract

This review provides the hydration and volume expansion mechanism of expansive materials, with the goal of utilizing them in the development of sustainable mining methods. The main focus of the review will be the newly developed non-destructible rock fragmentation method, slow releasing energy material agent (SREMA), which is a modified soundless chemical demolition agent (SCDA). The review aims to address one of the main gaps in studies related to SREMA, by presenting a thorough understanding of the components of SREMA and their mechanisms of action, leading to volume expansion. Thus, this review would act as a guide for researchers working on using expansive materials for rock breaking. As many literatures have not been published regarding the recently discovered SREMA, studies on cements, expansive cements, and soundless chemical demolition agents (SCDA) were mainly considered. The chemical reactions and volume expansive processes of these materials have been studied and incorporated with the additives included in SREMA, to understand its behavior. Literature containing experimental studies analyzing the heat of hydration and microstructural changes have been mostly considered along with some of the heavily discussed hypotheses regarding the hydration of certain components, to predict the volume expansive mechanism of SREMA. Studies related to SREMA and other similar materials have shown drastic changes in the heats of hydration as the composition varies. Thus, SREMA has the capability of giving a wider range of expansive energies in diverse environmental conditions

Green demolition technology of reinforced concrete slab: Application of soundless chemical demolition agents and its evaluation system

“…The feasibility of SCDAs in the demolition industry has been fully proved. CaO is the component with the highest proportion of SCDAs, which results in the volumetric expansion as an impact of the hydration products 19–21 . MgO, Al 2 O 3 , SiO 2 , etc., as the minor constituents, are used to improve the performance of SCDAs 13 .…”

“…CaO is the component with the highest proportion of SCDAs, which results in the volumetric expansion as an impact of the hydration products. [19][20][21] MgO, Al 2 O 3 , SiO 2 , etc., as the minor constituents, are used to improve the performance of SCDAs. 13 After the mixed slurry is poured into the hole, the increasing self-expansion is constrained by the medium around the hole.…”