Influence of treated bio-fibers on the mechanical and physical properties of cement mortars

Abstract

Alfa plant (Stipatenacissima L.) and wheat straw fibers were investigated as reinforcement in cementitious matrix. The fibers were used separately in three states: raw, wet (by immersion in water) and alkali treated. A reference mortar without fibers and mortars with 1% and 1.5% by volume of the two different bio-fibers were used. The mechanical and physical properties of mortar specimens were studied as well as the morphological analysis was carried out after 28 days of curing. The results exhibit that both Alfa and Straw fibre addition changed the mechanical performance of mortars in comparison to the reference mortar. A higher porosity and water absorption were observed after the addition of raw and wetted fibers. The alkali treatment caused morphological changes that were proved more efficient. This treatment provided a good result in terms of mechanical and physical properties. Furthermore, the addition of 1% by volume of alkali treated fibers affords both mechanical and physical properties better than the control mortar. SEM micrographs confirmed the good fibers/matrix adhesion of the alkali treated fibers.