Jin Chenhua, Wu Chang, Feng Chengcheng, Zhang Qingfang, Shangguan Ziheng, Pan Zuanfeng, Meng Shaoping
School of Civil Engineering, Southeast University, Nanjing 211189, China.
School of Public Administration, National Research Center for Resettlement, Hohai University, Nanjing 211100, China.
Materials (Basel). 2019 Aug 16;12(16):2607. doi: 10.3390/ma12162607.
Strain-hardening cementitious composite (SHCC) is a kind of construction material that exhibits multiple cracking and strain-hardening behaviors. The partial replacement of cement with fly ash is beneficial to the formation of the tensile strain-hardening property of SHCC, the increase of environmental greenness, and the decrease of hydration heat, as well as the material cost. This study aimed to develop a sustainable construction material using a high dosage of fly ash (no less than 70% of the binder material by weight). Based on the micromechanics analysis and particle size distribution (PSD) optimization, six mixes with different fly ash to cement ratios (2.4-4.4) were designed. The mechanical properties of the developed high-volume fly ash SHCCs (HVFA-SHCCs) were investigated through tensile tests, compressive tests, and flexural tests. Test results showed that all specimens exhibited multiple cracking and strain-hardening behaviors under tension or bending, and the compressive strength of the designed mixes exceeded 30MPa at 28 days, which is suitable for structural applications. Fly ash proved to be beneficial in the improvement of tensile and flexural ductility, but an extremely high volume of fly ash can provide only limited improvement. The HVFA-SHCC mix FA3.2 (with fly ash to binder ratio of about 76% by weight) designed in this study is suggested for structural applications.
应变硬化水泥基复合材料（SHCC）是一种具有多重开裂和应变硬化行为的建筑材料。用粉煤灰部分替代水泥有利于SHCC拉伸应变硬化性能的形成、环境友好性的提高、水化热的降低以及材料成本的降低。本研究旨在开发一种使用高掺量粉煤灰（不少于胶凝材料重量的70%）的可持续建筑材料。基于微观力学分析和粒度分布（PSD）优化，设计了六种不同粉煤灰与水泥比例（2.4 - 4.4）的配合比。通过拉伸试验、压缩试验和弯曲试验研究了所开发的高掺量粉煤灰SHCC（HVFA - SHCC）的力学性能。试验结果表明，所有试件在拉伸或弯曲时均表现出多重开裂和应变硬化行为，设计配合比在28天时的抗压强度超过30MPa，适用于结构应用。粉煤灰被证明有利于提高拉伸和弯曲延性，但极高掺量的粉煤灰只能提供有限的改善。本研究设计的HVFA - SHCC配合比FA3.2（粉煤灰与胶凝材料的重量比约为76%）建议用于结构应用。
