Performances of cementitious mortars containing recycled synthetic fibres under hot-dry climate

Abstract

The use of recycled synthetic fibres in cementitious materials can be considered as resources conservation and an adequate solution to some environmental problems. In this investigation, numerous tests have been carried out to study the performances of cementitious mortars reinforced by recycled synthetic fibres under hot-dry climate. These tests considered parameters such the consistency, the free and endogenous shrinkage, the flexural and the compressive strengths. The results revealed that recycled synthetic fibres can be successfully used as reinforcement for mortars exposed to hot-dry climate. The addition of recycled synthetic fibres to mortars leads to a lack of consistency for the mixture but reduces considerably the shrinkage and contributes to maintaining the mechanical behaviour. Indeed, mortars reinforced by 1% of recycled synthetic fibres and cured for a period of more than six months in hot-dry climate had their shrinkage reduced by 50% and their flexure and compressive strengths relatively maintained compared to the mortar without fibres. It is found that high temperature and low humidity conditions, which characterise a hot and dry climate, amplify the free shrinkage and decrease the long-term mechanical strengths of cementitious mortars, particularly in tension.