不同配合比下PVA-ECC强度及换算关系试验研究

Experimental Study on the Uniaxial Strength of PVA-ECC and Its Conversion Relation

本试验研究了PVA-ECC材料在7 d和28 d养护龄期下,砂胶比、水胶比及PVA纤维体积掺量对PVA-ECC材料强度的影响。试验研究表明:随PVA纤维体积掺量的增加,劈裂抗拉强度增加,但抗压强度有所降低;在7 d和28 d养护龄期下,随水胶比增大,抗压强度和劈裂抗拉强度显著降低。随砂胶比增大,PVA-ECC在7 d和28 d龄期的抗压强度均提高,但其劈裂抗拉强度在7 d龄期时减小,在28 d龄期时增大。在此基础上,建立了PVA-ECC在不同养护龄期下的强度换算关系、拉压强度换算关系,试验值与拟合值吻合度较高。本试验研究结果可为PVA-ECC的后续研究及实际工程应用提供参考。

The effects of sand-binder ratio, water-binder ratio and PVA fiber content on the strength of PVA-ECC at the 7 and 28-day curing age were studied. Experimental studies show that with the increase of the volume of PVA fiber, the tensile strength of splitting increases, but the compressive strength decreases to some extent;the compressive strength and splitting tensile strength decrease significantly with the increase of water-binder ratio at the 7 and 28-day age;with the increase of sand-to-gum ratio, the compressive strength of PVA-ECC increased at 7 d and 28 d, but the splitting tensile strength decreased at 7 d age and increased at 28 d. Based on that, the strength conversion relationship under different curing age and the tension-compression strength conversion relationship of PVA-ECC are established. The experimental values are in good agreement with the fitting values. The experimental results can provide reference for the follow-up research and practical engineering application of PVA-ECC.