废弃口罩纤维增强砂浆的性能研究

Properties of disposable medical masks fiber reinforced mortar

自新冠疫情爆发以来,废弃一次性医用口罩(disposable medical masks,DMMs)处理问题日益严峻,通过制备DMMs纤维增强砂浆,不仅可以大量回收利用一次性医用口罩,还可以提高砂浆的抗裂性能。研究了DMMs纤维长度、掺量对砂浆的力学性能、干燥收缩以及早期抗裂性能的影响,验证其应用于建筑材料的可行性。结果表明:DMMs纤维的掺入会略微降低砂浆的抗压强度;DMMs纤维长度增加会降低砂浆抗折强度的提升效果;砂浆的后期抗折强度随着DMMs纤维掺量增加呈现先升高后下降的趋势,DMMs纤维长度为15 mm、掺量为1.00%时,28 d抗折强度提升最高,相比基准砂浆提高了19.39%;而随着掺量增加,砂浆的干缩率持续下降,抗裂性能逐渐提高,DMMs纤维掺量为1.25%时,砂浆表面24 h内无裂缝出现。

In order to solve the increasing number of abandoned disposable medical masks(DMMs)problems since the COVID-19,it applied the DMMs fibers on the basis of previous experiments,performed the research on the effect and mechanism of microbeads proportion on the macro-performance of mortar,which included mechanical properties,dry shrinkage performance and early cracking resistance.The results showed that the DMMs fiber reduced the compressive strength of the mortar;the increased of DMMs fiber length reduced the improvement effect of the mortar flexural strength.The late flexural strength of the mortar increased first and then decreased with the increase of DMMs fiber content.When the DMMs fiber content was 1.00% and the length was 15 mm,the 28 d flexural strength performed best,which was 19.39% higher than the blank mortar.With the increased of the content,the dry shrinkage rate of the mortar continued to decrease and the crack resistance performance gradually improved.The early cracking resistance of mortar was the best with1.25% DMMs fiber,which can be manifested as no obvious cracks on the surface of the flat specimen within 24 h.