Effect of PVA fiber on mechanical properties of cementitious composite with and without nano-SiO_2

摘要

The present study investigated the effect of polyvinyl alcohol (PVA) fiber content on flowability, compressive strength, flexural strength, tensile strength and fracture performance of cementitious composites. The PVA fiber volume content added in the composites was varied from 0 to 1.5%. The studied composites were made without nano-SiO2 (NS) and with NS incorporation to evaluate the combined effects of PVA fiber and NS. A water-to-binder (wpb) ratio of 0.38 was used for the cementitious composites. All specimens for mechanical tests were cured in the condition of 20 degrees C and 95% relative humidity for 28 days. The results indicated that both PVA fiber and NS addition reduced workability of cementitious composites. PVA fiber significantly increased flexural strength, tensile strength, ultimate tensile strain, fracture energy and unstable fracture toughness while its impact on compressive strength and initiation toughness was limited. PVA fiber content affected tension zone more than compression zone. The optimum contents of PVA fiber for these mechanical properties were obtained as well. NS incorporation mainly affected workability and tensile strength. (C) 2019 Elsevier Ltd. All rights reserved.