Influence of a bioadmixture on standardized parameters of cementitious materials

International audienceA lipopeptide bioadmixture was used to modify the surface bio-contamination of concrete and their durability. Experimental investigations were intended to establish the influence of this bioproduct regarding different properties of mortar and/or cement paste samples. Standardized tests, such as slump test, flexural and compressive strength measurements as well as porosity determination, aim to confirm the ability of this bioproduct to be used as an admixture in cementitious materials. The bioadmixture introduced an effect on the workability of fresh samples with a plasticizing action. The bioproduct can improve the mechanical strength of Portand cement mortars depending on its content in samples and allows to reach resistances consistent with the standard strength class of samples. If the bioadmixture does not influence the total porosity available to water of the cement pastes, the mercury injection porosimetry has revealed the existence of a threshold from which the porous network of samples changes. The evolution of the surface roughness is also impacted by the bioadmixture, due to both curing time and interactions of the surface with water. The bioadmixture inhibits the development and the formation of crystals on the sample surfaces and modifies hydric transfers within the porous network of the samples