安徽理工大学
国家自然科学基金项目（面上项目）（52174102）
Anhui University of Science and Technology
National Natural Science Foundation of China ( General Project )（52174102）
基于光频域反射(OFDR)技术，利用分布式光纤提出了一种精确测量混凝土收缩与裂缝发展的方法，并通过室内试验，研究粉煤灰（FA）取代30%水泥、0.2%（体积掺量）聚丙烯纤维（PPF）及1%（体积掺量）钢纤维（SF）单掺和复掺对其收缩行为和裂缝形态的影响. 研究结果表明：该方法可以通过收缩与裂缝形成和扩展产生的应变场准确识别、定位、跟踪并量化其演变过程；在FA取代30%水泥的基础上，1%SF单掺可以使SCC干燥收缩应变从725με降低到314με，1%SF和0.2%PPF复掺可以使SCC收缩裂缝宽度从2.1mm减小至0.07mm.
A precise method for measuring concrete shrinkage and crack development was proposed based on Optical Frequency Domain Reflectometry (OFDR) technology, utilizing distributed optical fibers. Laboratory tests were conducted to investigate the effects of single and combined additions of 30% fly ash (FA) replacing cement, 0.2% (by volume) polypropylene fibers (PPF), and 1% (by volume) steel fibers (SF) on the shrinkage behavior and crack morphology of concrete. The results demonstrate that the proposed method can accurately identify, locate, track, and quantify the evolution of shrinkage and crack formation through strain fields generated by shrinkage and crack propagation. On the basis of 30% FA replacement for cement, the addition of 1% SF reduced the drying shrinkage strain of self-compacting concrete (SCC) from 725 με to 314 με, while the combined addition of 1% SF and 0.2% PPF reduced the SCC crack width from 2.1 mm to 0.07 mm.
