不同养护环境下SHCC单轴拉伸性能试验研究

发布时间：2018-05-15 22:11

本文选题：SHCC + 应变硬化　；参考：《河南理工大学学报(自然科学版)》2017年01期

【摘要】：为研究养护环境对应变硬化水泥基复合材料(strain hardening cementitious composite,SHCC)拉伸性能的影响,采用单轴拉伸试验对标准、室内和室外等3种环境下的SHCC进行了试验研究,获得了不同情况下的应力-应变曲线及相关参数。试验结果表明,在养护充分的情况下,不同环境条件下的SHCC材料均可表现出显著的应变硬化特征,极限拉应变能够达到3%以上,且具有良好的裂缝控制能力,极限应变下对应的平均裂缝宽度可以控制在125μm以内;与标准环境相比,室内环境下SHCC材料的强度有所降低,硬化现象不够显著,但其韧性没有降低,裂缝宽度能够控制在60μm以内;室外环境虽然较为复杂,但早期的充分养护能够使其保持性能稳定,抗拉强度和韧性没有出现明显下降,裂缝宽度可控制在80μm以内。采用引入名义初裂强度和名义初裂应变的双线性简化模型能够较好地描述不同环境下SHCC单轴拉伸应力-应变关系。研究成果表明,合适的养护环境下SHCC拉伸性能相对稳定,能够满足工程应用的要求。
[Abstract]:In order to study the effect of curing environment on the tensile properties of strain hardening cement matrix composites strain hardening cementitious compositeSHCC, uniaxial tensile tests were used to study the SHCC in standard, indoor and outdoor environments. The stress-strain curves and related parameters were obtained under different conditions. The test results show that under the condition of sufficient maintenance, the SHCC materials under different environmental conditions can exhibit remarkable strain-hardening characteristics, the ultimate tensile strain can reach more than 3%, and the SHCC material has good crack control ability. The average crack width under the limit strain can be controlled within 125 渭 m. Compared with the standard environment, the strength of SHCC materials in indoor environment is decreased, the hardening phenomenon is not significant enough, but its toughness is not reduced. The crack width can be controlled within 60 渭 m, while the outdoor environment is more complex, but the early sufficient maintenance can keep its performance stable, the tensile strength and toughness do not decrease obviously, and the crack width can be controlled within 80 渭 m. The simplified bilinear model with nominal initial crack strength and nominal initial crack strain can be used to describe the uniaxial stress-strain relationship of SHCC in different environments. The results show that the tensile properties of SHCC under proper curing environment are relatively stable and can meet the requirements of engineering application.
【作者单位】：河南理工大学土木工程学院;华升建设集团;
【基金】：国家自然科学基金青年项目(51208183) 河南理工大学博士基金资助项目(B2014-063)
【分类号】：TU528

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