混杂纤维再生混凝土轴压应力-应变关系研究

Stress-strain Relationship of Hybrid Fiber Reinforced Recycled Concrete Under Axial Compression

研究了再生粗骨料取代率、纤维的体积掺量和掺入方式对再生混凝土性能的影响,根据实测应力-应变曲线,计算出了各组试件的压缩韧度指数和弹性模量。结果表明:再生混凝土的抗压强度略低于天然骨料混凝土,掺入纤维可显著提高再生混凝土的抗压强度、韧性和弹性模量;单掺时,对于抗压强度和弹性模量,玻璃纤维、PVA纤维的最佳掺量分别为0.45%、0.05%,对于韧性,玻璃纤维、PVA纤维的最佳掺量分别为0.45%、0.10%;当再生粗骨料取代率为50%时,玻璃纤维和PVA纤维混杂掺加对再生混凝土抗压强度、韧性和弹性模量的提升效果优于单一纤维;当再生粗骨料取代率为100%时,单一纤维对再生混凝土抗压强度、韧性和弹性模量的提升效果优于混杂纤维。

The effects of recycled coarse aggregate replacement rate,fiber volume content and fiber mixing method on the properties of recycled concrete were studied.According to the measured stress-strain curve,the compressive toughness index and elastic modulus were calculated.The results show that the compressive strength of recycled concrete is slightly lower than that of natural aggregate concrete,and the addition of fibers can significantly improve the compressive strength,axial toughness and elastic modulus of recycled concrete.In single blending,for compressive strength and elastic modulus,the optimum content of glass fiber and PVA fiber is 0.45%and 0.05%respectively,and for toughness,the optimum content of glass fiber and PVA fiber is 0.45%and 0.10%respectively.When the replacement rate of recycled coarse aggregate is 50%,the improvement effect of mixed addition of glass fiber and PVA fiber on the compressive strength,toughness and elastic modulus of recycled concrete is better than that of single fiber.When the replacement rate of recycled coarse aggregate is 100%,the improvement effect of single fiber on the compressive strength,toughness and elastic modulus of recycled concrete is better than that of hybrid fiber.