Cotton knitted fabric waste as reinforcement in cement screed

Abstract

Cement screed consists of cement, sharp sand and water, laid as a thin layer over the concrete subfloor. Although the screed is strong, it can be additionally reinforced with fibres, most often polypropylene fibres. In this study, cotton knitted fabric waste (CKFW) was obtained from a local factory producing underwear to reinforce the cement screed. A total of eight mixtures were made: reference mixture, screed reinforced with polypropylene fibres and six mixtures reinforced with CKFW. CKFW was added in 1,25 %, 2,50 % and 5,00 % of the total volume. Before adding to the mixtures, the first CKFW group was saturated with tap water, whereas, the second CKFW group was saturated with dispersion that improves adhesion. The density and air content of the fresh mixtures were tested, and the compressive strength and flexural strength were determined when the specimens were 28 days old. The specific fracture energy is determined based on the curve from the plot of load vs. displacement. The CKFW increases the ductility of cement screeds, although it has no significant effect on the compressive and flexural strength of the specimens. The CKFW that was saturated with tap water achieved better results.