Durability of Mortar Containing Coal Bottom Ash as a Partial Cementitious Resource

Nafissatou Savadogo,William Prince Agbodjan,François Tsobnang,Adamah Messan,Kinda Hannawi

doi:10.3390/su12198089

Abstract

This research work focuses on the study of the durability of composite cements based on coal bottom ash powder produced by SONICHAR in Niger. After a physicochemical and environmental characterization of the coal bottom ash powder, mortar test specimens were made. In these specimens, 10%, 15% and 20% of cement were replaced by identical mass percentages of coal bottom ash powder. Durability studies focused on the determination of the chloride ions apparent diffusion coefficient, the measurement of the depth of carbonation and the accelerated ammonium nitrate leaching. The influence of carbonation and leaching were examined using the following parameters: pore distribution, gas permeability, porosity accessible to water, capillary absorption and electrical resistivity. The results show that the incorporation of coal bottom ash powder into CEM I leads to an increase in the depth of carbonation. This increase is more significant when the substitution rate exceeds 10%. In the leaching test, the partial substitution of coal bottom ash powder in CEM I up to 20% does not significantly affect the durability parameters of the composites compared to the control mortar. Diffusion test shows that for mortars containing less than 15% substitution, there is no significant influence on the chloride diffusion coefficient. A slight decrease is observed for mortar containing 20% substitution.

Highlights

On the one hand, Portland Artificial Cement (CEM I) has for many years been the most widely used building material in the world
The objective of this work is to study the durability of a cementitious mortar made from a bottom ash powder
Some samples of the mortar were subjected to carbonation and ammonium nitrate leaching and the consequences of these treatments were examined

Summary

Introduction

Portland Artificial Cement (CEM I) has for many years been the most widely used building material in the world. Its production is very energy-intensive and emits a significant amount of carbon dioxide (CO2). CO2 emissions from the cement industry have been estimated to account for nearly 5–7% of global emissions, with 0.9 tons of CO2 emitted into the atmosphere to produce one ton of cement [1]. The vast majority of developing countries and in particular those in sub-Saharan Africa show the highest demographic trends. There is a great need for housing and construction, which encourages the establishment of new cement plants in Africa. Burkina Faso has seen the creation of three (03) new cement plants on its territory in the year 2015 alone

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