Numerical and experimental investigation of the hygrothermal properties of corn stalk and magnesium phosphate cement (MPC) based bio-composites

This study includes the experimental and numerical investigation of the hygrothermal properties of magnesium phosphate cement (MPC) and corn stalk (CS) based bio-composites. Bio-composites were formulated using large size and small size corn stalk aggregates. Corresponding numerical models were established to investigate the effect of corn stalk aggregate on the hygrothermal properties of bio-composites. The validity of the numerical models was confirmed by comparing the experimental and numerical results. Hygrothermal properties of bio-composites were predicted through the heat and moisture transfer models. It was observed that numerical results showed satisfactory and close results with the experimental values. Finally, by using the proposed model, the effects of aggregates with different shapes and different volume fractions on heat and moisture transfer were studied. Results showed that the presented model is promising, and it can well evaluate the aggregates effect. The numerical results also showed that the aggregates effect can significantly affect the heat and moisture transfer. At the same time, the temperature effect cannot be ignored when predicting the heat and moisture transfer of the material. With increasing temperature, the aggregate effect will be relatively weakened. Meanwhile, based on this numerical model, the effect of temperature on sorption isotherm and relative humidity distributions in the bio-composites can be well predicted.