Preparation and properties of pretreated jute fiber cement-based composites

In order to resolve the contradiction of poor compatibility between plant fiber and cement-based materials and improve the toughness and durability of cement-based composites, this paper takes jute fiber cement-based composites as the research object, and proposes the pretreatment method of jute fiber through mass loss rate and water absorption test. The influence of pretreated jute fiber on the properties of cement-based composites was investigated by means of mechanical properties and frost resistance tests. The strengthening mechanism of jute fiber in the pre-treatment of cement-based composite materials was revealed from a microscopic perspective using scanning electron microscopy and mercury porosimetry. The results indicate that the quality loss rate of jute fiber soaked in hot alkali solution ( 60 ℃, 4% NaOH solution) was the largest, which was 37.94%. After dipping in 10% chloroprene latex, the fiber water absorption was the smallest, which was 0.93%. Therefore, the jute fiber was pretreated by the combination of hot alkali solution soaking and chloroprene latex impregnation. The pretreatment of fibers will reduce the fluidity of the composites, but has little influence on the setting time of the composites. The flexural strength, splitting tensile strength, dry shrinkage and frost resistance of the composites are significantly improved by the pretreatment fiber, but the compressive strength is slightly insufficient. The jute fiber after pretreatment can achieve reinforcement, crack resistance and toughening, reduce the porosity of cement-based composites, and optimize the pore structure inside the cement-based composites.