Physical and mechanical properties of sustainable vegetal concrete exposed to extreme weather conditions

Abstract

This paper studies the durability properties of vegetal concrete exposed to extreme environmental conditions including immersion weathering, outdoor weathering, salt attack, and freeze-thaw attack. Magnesium phosphate cement (MPC) binder containing high percentage of red mud and fly ash was mixed with the corn stalk based vegetal aggregates. It was found that all samples exposed to immersion weathering, outdoor weathering, and freeze-thaw attack showed a loss in mass, reduction in sample area, and decrease in compressive strength, which was associated with the dissolution and leaching out of the binder. Increase in the mass and swelling was observed for the vegetal concrete mixtures immersed into salt solution due to formation of salt layer on the surface of binder and vegetal aggregate. It was concluded that incorporation of fly ash, high compaction of samples, and pretreated aggregates improved the durability performance of vegetal concrete against extreme weather conditions.