Study on the effect of wood admixture on the physical and mechanical properties of corn cob ecological recycled concrete

Abstract

This paper investigates the physical and mechanical properties of ecological concrete using corn cob pellets, shavings, and wood chips. Wood chips and shavings were partially used as substitutes for corn cob particles to enhance the physical and mechanical properties of the eco-concrete. The impact of substitution on the macroscopic physical and mechanical properties is examined based on various pore structures. The pore size distribution was analyzed using the non-destructive testing technique of nuclear magnetic resonance (NMR). The pore complexity is analyzed through fractal dimension analysis. The pore distribution was assessed using magnetic resonance imaging (MRI). The roughness of pore distribution was analyzed by combining gray theory and counting the box dimension. The addition of biomass particles results in a 22-fold increase in the content of harmful pores, which can be quantitatively and visually observed using NMR and MRI techniques. This is the reason of compressive strength deterioration. Additionally, the optimal substitution of wood chips is determined. With a maximum biomass admixture of 50%, the uniaxial compressive strength increased by 18.9% (to 2.565 MPa, which meets the strength requirements of self-bearing wall insulation blocks). This study aims to establish a foundation for utilizing ecological concrete in agricultural facilities and rural wall materials.