Engineering

Materials science

Slump

Ceramic

Ultimate tensile strength

Aggregate (composite)

Durability

Waste management

Microstructure

Composite material

Absorption of water

Mechanical strength

Scanning electron microscope

Flexural strength

Properties of concrete

Compressive strength

Journal of Building Engineering

This paper investigated the combined utilization of recycled waste ceramic aggregate (RWCA) and waste carpet fibers (WCFs) in high strength concrete (HSC). Concrete mixes containing different percentages of RWCA including 20%, 40%, 60% (by weight) as partial replacement of natural coarse aggregate (NCA) were prepared. To enhance the tensile and flexural strength of concrete, 1.0% (by volume) WCF was added to the mixes. The slump and density of the fresh concrete were evaluated, both of which demonstrated a decreasing trend with incorporation of RWCA and WCF. With regard to the hardened concrete, replacing 40% of NCA with RWCA led to the optimum mechanical properties and increased the compressive, splitting tensile, and flexural strengths by 13%, 15%, and 3%, respectively, over those of the control concrete after 28 days. Adding WCF to the same mix enhanced the tensile strength up to 21% over that of the control concrete and reduced the crack width. Regarding the durability properties, the optimum RWCA concrete reinforced with WCF showed 19% reduction in the 28-day electrical resistivity and 48% increase in water absorption. The scanning electron microscopy (SEM) images of WCF-reinforced concrete confirmed the bridging effect of WCF, which led to an enhancement in the tensile and flexural strengths of concrete. Based on the findings of the present study, it is possible to produce fiber-reinforced HSC with superior compressive and tensile strength by using specific dosages of RWCA.

Green high strength concrete containing recycled waste ceramic aggregates and waste carpet fibers: Mechanical, durability, and microstructural properties