机场道面混掺纤维混凝土强度与抗弯韧性试验

为了降低机场道面混凝土脆性，通过混掺高性能粗聚烯烃纤维（PP）和细聚乙烯醇纤维（PVA）来提高道面混凝土韧性。通过四点弯曲试验，测得了梁试件荷载 挠度曲线，分析了2种纤维体积掺率混掺对改善三级配机场道面混凝土弯曲韧性的效果。结果表明:纤维混掺可明显改善混凝土抗弯韧性；PP的掺入使荷载 挠度曲线出现了2次峰值；PVA体积掺率为0.2%或0.4%时，随着PP掺率增加，韧性指标值P₃₀₀，P₇₅，P₅₀均呈增大趋势；PP掺率的增加对后期韧性指标值P₇₅，P₅₀的提高更为显著；增加PVA掺率对提高第一峰值强度较为显著；PP和PVA分别以体积掺率1.1%和0.4%混掺时，机场道面混凝土抗弯韧性提高最为明显。

Experiment on Strength and Flexural Toughness of Hybrid Fiber Reinforced Concrete for Airport Pavement

In order to reduce the brittleness of airport pavement concrete, the toughness of pavement concrete was improved by mixing high performance coarse polyolefin fiber (PP) and fine polyvinyl alcohol fiber (PVA). By four point bending test, the load deflection curves of beam specimens were obtained, and the improving effects of mixing ratio of two different fibers on the flexural toughness of three graded airport pavement concrete were analyzed. The results show that the flexural toughness of concrete can be significantly improved by fiber mixing. There are 2 times of peak values of load deflection curves when PP is mixed. When volume ratio of PVA is 0.2% or 0.4%, with the increase of PP mixing ratio, the toughness index values P3₀₀, P₇₅, P₅₀show an increasing trend. The late toughness index values P₇₅, P₅₀can be improved more obviously when PP mixing ratio increases. The first peak strength can be more significantly improved when PVA mixing ratio increases. When the volume ratios of PP and PVA are 1.1% and 0.4% respectively, the flexural toughness of airport pavement concrete is most obviously improved.