Evaluation of CO2 sequestration efficiency by Pozzolime concrete

Abstract

Reducing CO2 emissions from cement industry is vital. Portland cements manufacturing is responsible for 5 – 8 % of global greenhouse gases. Therefore, using alternative binders in concrete is necessary to reduce the environmental impact of cement. This work goals to investigate the efficiency of Pozzolime concrete in CO2 sequestration from the environment and then to convert it into calcium carbonate inside the concrete. The Pozzolime concrete was tested at the ages of 14, 28 and 56 days with two moist-curing ages; 14 and 28 days. The studied mixes were exposed to 15 and 25 % of CO2 concentration for a period of 24 hours. The efficiency was evaluated through compressive strength, carbonation depth, CO2-uptake and weight change. The results showed that higher concentration of CO2 for exposure of 24 hours caused a significantly higher carbonation depth. The maximum CO2 uptake was recorded at the age of 14 days for Pozzolime concrete, when exposed to 25% concentration of CO2.