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为研究碳纤维(CF)对纳米偏高岭土再生混凝土(NRAC)力学性能的影响，以纳米偏高岭土(NMK)掺量、CF掺量、再生粗骨料(RA)取代率、CF长度作为影响因素进行正交试验，研究CF对NRAC抗压强度、抗拉强度以及拉压比的影响，结合压汞法及扫描电镜法对再生混凝土(RAC)孔隙结构及微观形貌进行分析，得出其改善机理。结果表明：RA取代率和NMK掺量对抗压强度影响效果显著，CF掺量对抗拉及拉压比影响效果显著；在优先考虑RAC抗压强度、抗拉强度以及拉压比的情况下，最优配比分别为：A3B4C1D2、A1B3C1D3、A1B3C4D3;CF的掺入增加RAC的孔隙率，但由于NMK的存在，孔隙率只呈现少量增加。此外CF的分隔及阻裂效应细化RAC的孔隙结构；CF通过桥接，起到承载作用的同时，使得裂缝扩展路径更为复杂，不易产生贯穿裂缝。并且NMK的填充及火山灰效应可增强纤维-砂浆界面过渡区的粘结强度，进一步发挥CF的增强作用，由此提高RAC的强度及延性。
Abstract：In order to study the effect of carbon fiber(CF) on the mechanical properties of nano metakaolin recycled concrete(NRAC), orthogonal tests were conducted using the content of nano metakaolin(NMK), CF content, the replacement rate of recycled coarse aggregate(RA) and the length of CF as influencing factors to study the effects of CF on the compressive strength, tensile strength and tension-compression ratio of NRAC.The pore structure and micro-morphology of recycled concrete(RAC) were analyzed by mercury intrusion method and scanning electron microscope method, in order to find out the improvement mechanism of CF on NRAC. The results show that the replacement rate of RA and the content of NMK have significant effects on the compressive strength, and the content of CF has remarkable effects on the tensile strength and tensioncompression ratio. Considering the compressive strength, tensile strength and tension-compression ratio of recycled concrete, the optimal ratios are A3B4C1D2, A1B3C1D3, A1B3C4D3, respectively. The incorporation of CF increases the porosity of RAC, but the porosity increases only slightly due to the presence of NMK. In addition,the separation and crack resistance effect of CF refine the pore structure of RAC. CF plays a bearing role through the bridge function, which makes the crack propagation path more complicated and is not easy to produce transverse cracks. Moreover, the filling effect and volcanic ash effect of NMK enhance the bond strength of the transition zone of fiber-mortar interface, further play the strengthening role of CF, and thus improving the strength and ductility of RAC.
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基本信息:
DOI：
中图分类号:TU528
引用信息:
[1]阎杰,罗岩,于旭涛等.碳纤维对纳米偏高岭土再生混凝土力学性能及微观结构试验研究[J].中国测试,2025,51(06):17-24.
基金信息:
河北省教育厅自然科学重点项目(ZD2022066); 河北省建设科技研究指导性计划项目（2022-2107）