Experimental investigation on two new corn stalk biocomposites based on magnesium phosphate cement and ordinary Portland cement

This paper reports a comparative investigation of two new corn stalk (CS) biocomposites based on magnesium phosphate cement (MPC) and ordinary Portland cement (OPC). Two composites with identical corn stalk contents and different binders were prepared. The porosity, water absorption, drying kinetics, compressive strength and thermal properties of the biocomposites were measured. The experimental results show that the lower open porosity of the CS-MPC concrete results in lower water absorption and weaker evaporation performance. In addition, the open porosity and closed porosity play important roles in the effect of temperature on the thermal properties in the dry state and moist state. The dry and moist thermal conductivities of CS-MPC concrete is slightly higher than that of the CS-OPC concrete, which can meet the thermal insulation requirements. Due to the excellent bonding between the MPC binder and corn stalk plant aggregates, the compressive strength of CS-MPC concrete is significantly higher than that of CS-OPC concrete. These results indicate that MPC binder is more suitable for producing plant aggregate concrete.