Treatment of date palm fibres mesh: Influence on the rheological and mechanical properties of fibre-cement composites

摘要

An experimental study was conducted on the influence of different treatments of date palm fibres on the properties of mortars in both fresh and hardened states. Three types of treatment were discussed: boiling water treatment, sodium hydroxide treatment and a polymer surface treatment based on linseed oil. As a first step, tests of water absorption, setting times and direct tensile strength were performed on single fibres to assess the relevance of the predominant parameter for each treatment. Thereafter, unreinforced mortar and mortars reinforced with raw and treated date palm fibres were made and tested using a flow table test, as well as for porosity accessible to water, three-point bending strength, compressive strength and capillary water absorption. The results for individual fibres show that treatments with a 3-hour boiling of the fibres, a 3% NaOH concentration, and a 1.5% linseed oil/fibre ratio yield the lowest absorption kinetics, the shortest setting times, and the most interesting tensile properties. However, the results for fibrous composites indicate that the workability of mortars reinforced with linseed oil treated fibres was improved compared with raw fibres. In the hardened state, boiling and sodium hydroxide treatments improve the flexural strength of the composites. The same trend was observed for compressive strength. Therefore, the mortar reinforced by fibre treated with linseed oil does not improve the strength and is the most porous. The incorporation of date palm fibres decreases the kinetics of the capillary absorption of mortars compared to unreinforced mortar. The lowest absorption coefficients are obtained after the treatment with linseed oil. (C) 2020 Elsevier Ltd. All rights reserved.