Setting characteristics of natural cellulose fiber reinforced cement composite

Abstract

In this study, the setting characteristics of natural cellulose fiber-reinforced cement composites were investigated based on the hemp and jute fiber dosages (0, 0.25, 0.5, 1, and 2%) as the main variables. The fiber cross-section was observed to have a hollow bundled tube structure via scanning electron microscopy. The compressive strength of the composite with a fiber mix proportion of 0.25% was greater than that of the plain sample. The compressive strengths of the other composites decreased gradually with increased fiber mix proportion, presumably an effect of agglomeration of fibers. The ultrasonic pulse velocity (UPV) and heat of hydration over time were measured to verify the effect of fibers on the cement hydration reaction. Further, the initial and final setting times were calculated based on the measurement results. The experimental results indicated that the higher the dosage of the hemp and jute fibers, the longer the initial and final setting times become. This appears to be the effect of cellulose and pectin comprising the fiber. In the case of the specimen with high fiber content, it was difficult to predict the setting performance by measuring UPV owing to the fiber network configuration and the chemical reaction between fiber and cement. © 2020 Elsevier Ltd