Durability and strength characteristics of high-strength concrete incorporated with volcanic pumice powder and polypropylene fibers

In this paper, the partial replacement of volcanic pumice powder (VPP) was investigated for use as a supplementary cementitious material. High-strength concrete (HSC) was prepared using two sets of VPP (10% and 20%) incorporated with three sets of polypropylene fiber (PF) (0.20%, 0.35%, and 0.50%) to produce different concrete mixtures. Several tests, including slump, compressive strength, indirect tensile strength, flexural strength, water absorption, initial surface absorption, and sorptivity, were conducted to evaluate HSC performance. Results showed the prepared specimens with 10% cement replacement with VPP and 0.20% PF content indicated a slight increase in compressive strength compared with the control concrete at later ages. Indirect tensile and flexural strengths were optimized at 10% VPP replacement with 0.50% PF content. Furthermore, adding PFs to mixes increased indirect tensile and flexural strength but decreased slump. The sorptivity test indicated low water soaking due to VPP content in the mixes compared with the control mix (HSC); it declined as the replacement of VPP increased. The different standard tests on mixes depicted favorable results and good prospects for the inclusion of VPP in HSC structures.