Diao Pinxin, Ling Zongyou, Bai Yunbo, Lu Weihua, Zhang Yongxing
School of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China.
Industry and Information Technology Bureau of Fangchenggang City, Fangchenggang 538001, China.
Materials (Basel). 2024 Feb 8;17(4):831. doi: 10.3390/ma17040831.
Strain-hardening cementitious composite (SHCC) has the obvious advantages of excellent material properties such as its high tensile and compressive strengths, high tensile strain capacity, and excellent durability against multi-cracking performance with very fine crack widths. In particular, the multi-cracking performance of SHCC during structural utilization is obviously reduced compared to that of SHCC in uniaxial tension tests using dumbbell-shaped specimens of small size. The corresponding tensile strain capacity of SHCC during structural utilization is, thus, significantly decreased compared to that of SHCC in uniaxial tension tests. However, the reduction in the ductility of SHCC during structural utilization has not been sufficiently understood, and further study is required. This paper presents an experimental investigation into the ductility variation of flexural-failed and shear-failed SHCC members as well as the ductility improvement of SHCC members with steel reinforcement compared with that of SHCC in uniaxial tension tests using small-sized specimens. This study focuses on not only the decrease in the crack elongation performance of the SHCC material during structural utilization but also the increase in the crack elongation performance of SHCC members with steel reinforcement. The results demonstrate that the crack elongation performance of flexural-failed and shear-failed SHCC members is significantly reduced compared to that of SHCC in the uniaxial tension tests. Moreover, it was confirmed that steel reinforcement can effectively improve the SHCC member, increasing the strain-hardening capacity and multi-cracking performance. The load-carrying capacity of the flexural-failed SHCC member with steel reinforcement seemed to increase linearly with an increase in the reinforcement ratio, accompanied by an increase in the distribution of multiple fine cracks in the flexural-failed SHCC member with steel reinforcement.
应变硬化水泥基复合材料（SHCC）具有明显的优势，其材料性能优异，如具有较高的抗拉强度和抗压强度、较高的拉伸应变能力，以及在多裂缝性能方面具有出色的耐久性，裂缝宽度非常细。特别是，与使用小尺寸哑铃形试件进行的单轴拉伸试验中的SHCC相比，SHCC在结构使用过程中的多裂缝性能明显降低。因此，与单轴拉伸试验中的SHCC相比，SHCC在结构使用过程中的相应拉伸应变能力显著降低。然而，SHCC在结构使用过程中延性的降低尚未得到充分理解，需要进一步研究。本文对弯曲破坏和剪切破坏的SHCC构件的延性变化以及与使用小尺寸试件的单轴拉伸试验中的SHCC相比，配筋SHCC构件的延性改善进行了试验研究。本研究不仅关注SHCC材料在结构使用过程中裂缝延伸性能方面的降低，还关注配筋SHCC构件裂缝延伸性能方面的提高。结果表明，与单轴拉伸试验中的SHCC相比，弯曲破坏和剪切破坏的SHCC构件的裂缝延伸性能显著降低。此外，证实了配筋可以有效地改善SHCC构件，提高应变硬化能力和多裂缝性能。配筋的弯曲破坏SHCC构件的承载能力似乎随着配筋率的增加而线性增加，同时配筋的弯曲破坏SHCC构件中多条细裂缝的分布也增加。
