Mechanical properties of seawater sea-sand concrete reinforced with discrete BFRP-Needles

Abstract

To recycle the fiber-reinforced polymer (FRP) waste, a new type of discrete slender FRP element reinforced seawater sea-sand concrete (SWSSC) was proposed in this paper. This element, referred to as “Basalt-FRP (BFRP)-Needles”, is produced by cutting BFRP bar waste into 100 mm rod-shaped elements. BFRP-Needles were incorporated into SWSSC to partially replace the coarse natural aggregate by volume. Test results indicate that there was no significant difference in the compressive strength for SWSSCs that incorporated 6 mm, 8 mm or 10 mm BFRP-Needles with the same volume replacement ratio. When the volume replacement ratio was less than 15%, the compressive strength decreased with the increasing replacement ratio, and the maximum decrease was 10%. The splitting tensile strength of specimens with a 5%, 10%, 15%, and 20% volume replacement ratio was increased by 4%, 11%, 2%, and 32%, respectively, compared to that of the NA (Control) specimen. The flexural strength of specimens with a 5%, 10%, 15%, and 20% volume replacement ratio was decreased by 6%, 14%, 10%, and 6%, respectively, compared to that of the NA (Control) specimens. The incorporation of BFRP-Needles in SWSSC resulted in significant increases in the fracture toughness, especially for the high volume replacement ratio of 20%.