粉煤灰粒径和纤维对混凝土性能的影响

EFFECTIVENESS OF FLY ASH PARTICLE SIZE AND FIBER ON CONCRETE PROPERTIES

研究将普通粉煤灰(FA)和超细粉煤灰(UFA)按不同比例替代水泥制备普通粉煤灰混凝土(FAC)和超细粉煤灰混凝土(UFAC),进行工作性、力学和氯离子渗透等工程性能的研究,通过加入PVA纤维进一步研究纤维对粉煤灰混凝土工程性能的影响。采用二次多项式拟合手段建立粉煤灰和PVA纤维掺量与上述工程性能的回归模型。结果表明当粉煤灰掺量为25wt%时,UFAC的抗压和抗折强度分别比FAC提高28.39%和13.92%,电通量降低了23.47%。当PVA纤维掺量为0.17%时,混凝土的性能达到最优。这表明UFAC具有比FAC更高的工程价值,PVA纤维可进一步提升粉煤灰混凝土的力学和抗氯离子渗透性能。

Ordinary fly ash(FA)and ultrafine fly ash(UFA)are substituted for cement in different proportions to prepare ordinary fly ash concrete(FAC)and ultrafine fly ash concrete(UFAC),engineering properties of which,such as workability,mechanics and chloride ion penetration are investigated.The effectiveness of fibers on the engineer⁃ing properties of fly ash concrete is further studied by adding PVA fibers.A quadratic polynomial fitting is used to establish the regression model among the fly ash,PVA fiber admixtures,and the above engineering properties.The re⁃sults show that the compressive and flexural strengths of UFAC increase by 28.39%and 13.92%,respectively,and the electric flux decreases by 23.47%comparing with FAC when the fly ash admixture is 25 wt%.The optimal performance of the concrete is obtained when the PVA fiber admixture was 0.17%,indicating that UFAC has higher engineering value than that of FAC,and PVA fiber can further improve the mechanical and chloride ion penetration resistance of fly ash concrete.