Effect of low-modulus polypropylene fiber on physical and mechanical properties of self-compacting concrete

The article presents the results of laboratory experiments investigating the necessity and expediency of disperse reinforcement of self-compacting concrete (SCC) to increase its physical and technical parameters and the study of deformative properties of SCC with the use of fibers. For collaboration with manufacturers to improve physical and mechanical properties and durability, to deduce basic laws, researchers on the basis of previously published results, offered disperse reinforcement of SСС by polypropylene fibers of 6, 9, 12, 15 mm in size and quantity from 0.5 to 2 kg per 1 m3 of concrete mixture. From the work done it can be concluded that the addition of 1–2 kg per 1 m3 of fiber with 9÷15 mm in size improves the physical and technical properties of SCC, such as flexural strength by 10%, and shrinkage deformations reduced to 75% compared to the concrete without fiber. In the course of this study, it was found that the disperse reinforcement with low-modulus fiber increases the characteristics of SCC in production. Based on the results obtained, practical recommendations for the optimal size and amount of fiber in SCC were presented in order to derive the optimal price-quality ratio, as well as to improve the quality of concrete works at high temperatures > 20 °C.