混合捶灰是乐山大佛修缮中使用的一种兼具气硬与水硬性的修复材料。为解决大佛头面部等多处的修复材料受赋存环境影响而出现的开裂、剥落等问题,采用黄麻纤维(HF)和碳酸钙晶须微纤维(CWF)复掺的方式对其进行增强。结果表明,HF在提升材料抗折强度方面的表现优于CWF,而CWF的掺入则有效提升了材料韧性和劈裂抗拉强度,二者复掺能够取得综合性的增强效果。28d时,复掺试件的抗折强度较未掺杂时最大提升程度为35.73%,劈裂抗拉强度最大提升程度为20.88%,均高于对应掺量的单掺组试件。此外,复掺组试件在耐水性和耐酸性测试中的表现优于对照组和单掺组,这表明多尺度纤维复掺的方法有助于实现材料强度与耐候性的综合提升。

Mixed hammered ash is a kind of repair material with both hydraulicity and air hardening properties used in the restoration of Leshan Giant Buddha. To solve the problems of cracking and peeling caused by the influence of the environment on the repair materials of the head and face of the Buddha, hemp fiber (HF) and Calcium carbonate whisker fiber (CWF) are used to enhance this material. The results show that HF performs better than CWF in improving the flexural strength of materials, and the addition of CWF effectively enhances the toughness and splitting tensile strength of the material. The combination of the two can achieve a comprehensive strengthening effect. After 28 days of curing, the maximum increase in flexural strength of the composite specimens compared to the undoped specimens was 35.73%, and the maximum increase in splitting tensile strength was 20.88%, both of which were higher than those of the corresponding single doping group specimens. In addition, the performance of the composite group specimens in water resistance and acid resistance tests is better than that of the control group and the single addition group, indicating that the multi-scale fiber composite method helps to achieve a comprehensive improvement in material strength and weather resistance.

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国家重点研发计划(No. 2021YFC1523400)及重庆市技术创新与应用发展专项重点项目(No. CSTB2022TIAD-KPX0095)。