【摘要】 为明确轻质超高性能混凝土（LUHPC）的耐久性能，通过采用不同钢纤维掺量（1.5%、2.0%、2.5%）,设计制备9组LUHPC试件，经标准养护28 d后，开展快速氯离子渗透、500次冻融循环和28 d碳化试验，掌握了不同钢纤维掺量下LUHPC的耐久性，明确了LUHPC耐久性等级。结果表明，LUHPC的氯离子扩散系数为2.4×10^-13～3.9×10^-13 m²/s,冻融循环的质量损失率小于1%,相对动弹性模量大于95%,碳化深度基本为0 mm,由此得到LUHPC耐久性等级分别为RCM-Ⅴ、F500和T-Ⅴ,显示出LUHPC良好的耐久性能，可满足桥梁结构的耐久性设计要求。更多还原

【Abstract】 In order to determine the durability of lightweight ultra-high performance concrete（LUHPC）,9 sets of LUHPC samples were designed and prepared by using different steel fiber content（1.5%,2.0%,2.5%）.After standard curing for 28 d, rapid chloride ion penetration, 500 freezing-thawing cycles and 28 d carbonization tests were carried out.The durability of LUHPC under different steel fiber content was mastered, and the durability level of LUHPC was defined.The results show that the chloride ion diffusion coefficient of LUHPC is 2.4×10^-13～3.9×10^-13 m²/s, the mass loss rate of freeze-thaw cycle is less than 1%,the relative dynamic elastic modulus is greater than 95%,and the carbonization depth is basically 0 mm.Thus, the durability grades of LUHPC are RCM-Ⅴ,F500 and T-Ⅴ,respectively.The LUHPC has good durability and can meet the durability design requirements of bridge structures.更多还原