不同纤维对高强抗裂粘结砂浆的性能影响研究
Study on the Influence of Different Fibers on the Properties of High Strength Crack Resistant Bond Mortar

本文选用钢纤维和聚丙烯纤维两种常见纤维开展试验，通过测试砂浆的力学性能、粘结劈拉强度等指标，探究纤维对砂浆性能的影响规律及其作用机理。结果表明，适量掺入纤维可显著提升砂浆的综合性能。当钢纤维掺量为1.5%时，砂浆的28天抗压、抗折强度分别较空白组提高8.35%、87.00%，力学性能增强效果最佳。钢纤维掺量为2.0%时，砂浆粘结劈拉强度达到峰值，相比空白组提升207.84%。与钢纤维相比，聚丙烯纤维对砂浆的性能改善幅度较小，掺量为0.2%时，砂浆的抗压及抗折强度达到最大值。分析可知，纤维主要通过桥联作用和阻裂作用改善砂浆性能，但过量掺入会引起纤维团聚，导致砂浆基体缺陷增多、性能降低。此外，钢纤维可增大砂浆–混凝土界面摩擦阻力和机械咬合力，从而提高砂浆粘结性能。
In this paper, two common fibers, steel fiber and polypropylene fiber, are selected to carry out experiments. By testing the mechanical properties of mortar, bond splitting strength and other indicators, the influence of fiber on the performance of mortar and its mechanism are explored. The results show that the appropriate amount of fiber can significantly improve the comprehensive properties of mortar. When the steel fiber content is 1.5%, the 28-day compressive strength and flexural strength of mortar are increased by 8.35% and 87.00%, respectively, compared with the blank group, and the mechanical properties are enhanced best. When the steel fiber content is 2.0%, the adhesive splitting tensile strength of mortar reaches the peak value, which is 207.84% higher than that of blank group. Compared with steel fiber, polypropylene fiber can improve the performance of mortar less. When the content is 0.2%, the compressive strength and flexural strength of mortar reach the maximum. The analysis shows that fiber can improve the performance of mortar mainly through bridging and crack inhibition, but excessive incorporation will cause fiber agglomeration, resulting in increased defects and reduced performance of mortar matrix. In addition, steel fiber can increase the friction resistance and mechanical bite force of mortar - concrete interface, so as to improve the bond property of mortar.