Incorporation of Disposed Face Mask to Cement Mortar Material: An Insight into the Dynamic Mechanical Properties

Incorporating masks into building materials offers a potential solution to the environmental threat of disposable masks with promising material performance. However, research on their dynamic properties is lacking to further determine the application range of the new composite. This study addresses this gap by shredding face masks into strips and incorporating them into mortars at varying volume ratios. The integrity and compactness of the mortar was measured and characterized by P-wave velocity, while dynamic compression properties were explored using a split Hopkinson pressure bar (SHPB) system. Subsequently, sieve analysis was conducted on the fractured specimens. The results indicate that incorporating masks generally improves the mortar integrity and the fragmentation after impacting. The dynamic uniaxial compression strength (DUCS) decreased for all mixing designs compared to plain ones under a constant loading rate. Meanwhile, the dissipated energy density showed a similar trend to the P-wave velocity, exhibiting less pronounced enhancement at higher loading rates. According to the dynamic characteristics, a dynamic constitutive model based on the Lemaitre principle and Weibull distribution of damage is developed and validated. The test results are further understood through the perspective of the mechanism of mask inclusion.