南方高温地区水泥混凝土路面早期裂缝防治研究

Analysis on Prevention of Inchoate Cracks in Cement Concrete Pavement of South High Temperature Area

研究了三种外掺料对路面混凝土早期开裂性能的影响。通过理论分析,将水泥路面的早期开裂机理归结为混凝土具有塑性收缩、自收缩和干缩等早期收缩性能;采用室内试验分别研究了聚丙烯纤维、钢纤维和粉煤灰对混凝土早期收缩性能的改善效果。研究结果表明,聚丙烯纤维和粉煤灰能够大幅度降低混凝土的早期收缩值,钢纤维的改性作用则不明显。建议为全面评价不同混凝土的长期开裂性能,应增加开裂后的疲劳和冲击试验研究。

The effect of three admixture on the inchoate cracking performance of pavement concrete is studied, The mechanism arc concluded that concrete has three inchoate shrinkage properties including plastic shrinkage cracking, dry shrinkage and self shrinkage. The modification effect of polymer fiber, steel fiber and fly ash on the inchoate shrinkage properties of concrete arc respectively re- searched through lab experiments. The results showed： polymer fiber and fly ash can decrease the inchoate shrinkage value but steel fiber not. Finally it suggested that the fatigue and shock experiment after cracking should be increased for evaluating long cracking performance of concrete.