胶粉纤维改性水泥稳定碎石抗裂性能研究

Study on the crack resistance of cement stabilized macadam modified by rubber powder fiber

针对水泥稳定碎石基层易开裂问题,在混合料中掺入适量胶粉及聚乙烯醇(PVA)纤维,开展强度、抗压回弹模量、干缩性能和扫描电镜试验(SEM);分别掺入橡胶粉、改性胶粉、PVA纤维、不同水泥剂量的胶粉纤维,对比其对混合料抗裂性能的影响。发现掺入材料对水泥稳定碎石混合料性能具有明显影响。掺入胶粉、改性胶粉后会降低混合料强度和抗压回弹模量,提升抗干缩性能;掺入纤维能增强混合料强度、模量和抗干缩性能;加入不同水泥剂量的胶粉纤维对混合料强度、抗压回弹模量提升效果明显,但降低了抗干缩性能;宏观力学指标试验和SEM试验结果显示出改性胶粉纤维与水泥基具有良好的黏结性,可以提升水泥稳定碎石混合料的抗裂能力。

To address the cracking issues prevalent in cement-stabilized macadam base layers,an appropriate blend of rubber powder and polyvinyl alcohol fibers was integrated into the mix.Comprehensive evaluations through strength,compressive rebound modulus,shrinkage performance,and scanning electron microscopy(SEM)tests were conducted.These assessments aimed to discern the effects of various admixtures,including rubber powder,modified rubber powder,fibers,and varied cement dosages,on the mixture's resistance to cracking.The empirical results indicate a pronounced influence of these admixtures on the properties of the cement-stabilized macadam mixture.Specifically,the addition of rubber powder and modified rubber powder resulted in a reduction in strength and compressive rebound modulus,while enhancing shrinkage resistance.Conversely,the integration of fibers enhanced the mixture's strength,modulus,and resistance to shrinkage.A higher cement dosage significantly improved the strength and compressive rebound modulus,but reduced the shrinkage resistance.Macroscopic mechanical tests and SEM analysis further confirmed that modified rubber powder fibers exhibited robust adhesion with the cement matrix,substantially improving the mixture's crack resistance capabilities.