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Carbon dioxide sequestration is crucial for targets limiting global warming could be achieved. This paper discloses results of an investigation concerning the performance of fly ash/waste glass alkaline-based mortars with two additives and recycled aggregates exposed to accelerated carbon dioxide curing. Mechanical properties as well as water absorption, drying shrinkage and carbon sequestration potential were studied on it. The results show that the mixtures with calcium hydroxide and sodium hydroxide concentration of 8 M leads to the highest compressive strength (10 MPa) which is high enough for the production of masonry blocks. Significant correlations between the flexural strength and the compressive strength were noticed. The mixtures show a low water absorption by immersion (9%) as well as by capillary (1.4 kg/m 2 H 0.5 ). The results of the modulus of elasticity show that increasing the sodium hydroxide molarity increased the stiffness of the mixtures. The results of drying shrinkage are in line with the results of the capillary water absorption and of the elastic modulus. A maximum CO 2 sequestration (164 kgCO 2 eq/m 3 ) is noticed for the mixture with a sodium concentration of 8 M based on the additive calcium hydroxide. [ABSTRACT FROM AUTHOR]

Abstract: This study has investigated the joint effect of several factors on the workability and mechanical strength of alkali-activated metakaolin based mortars. The factors analysed through a laboratory experiment of 432 specimens, pertaining to 48 different mortar mixes were, sodium hydroxide concentration (10M, 12M, 14M, 16M), the superplasticizer content (1%, 2%, 3%) and the percentage substitution of metakaolin by calcium hydroxide in the mixture (5%, 10%). The results show that the workability decreases with the concentration of sodium hydroxide and increases with the amount of calcium hydroxide and superplasticizer. The results also show that the use of 3% of superplasticizer, combined with a calcium hydroxide content of 10%, allows improving the mortar flow from less than 50% to over 90%, while maintaining a high compressive and flexural strength. [Copyright &y& Elsevier]