| 摘要: |
| 采用10%，15%和20%预加拉伸应变，使养护7，28d龄期的高延性纤维增强水泥基复合材料(ECC)试件产生裂缝，研究其在经历10，20和30次硫酸盐干湿循环后的裂缝特性、自愈合后的拉伸性能及自愈合产物.结果表明：带裂缝试件在经历不同循环次数后均表现出了良好的自愈合效果，残余裂缝的最大宽度和数量明显减少；养护7d试件经历10次循环后的残余裂缝最大宽度由愈合前的80μm降至25μm，养护28d试件经历30次循环后的残余裂缝最大宽度由愈合前的100μm降至50μm；67%以上带裂缝试件自愈合后的单轴拉伸应变能力接近甚至超过同样经历的对比用无裂缝空白试件；养护7d试件自愈合后的最终应力可分别恢复至75%以上，养护28d试件可恢复至131%以上；层状结构的CaCO3晶体是ECC试件的主要自愈合产物. |
| 关键词: 高延性纤维增强水泥基复合材料 裂缝 自愈合 硫酸盐侵蚀 干湿循环 |
| DOI：103969/j.issn.1007 9629201902005 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51508329) |
|
| Self healing of ECC Materials under Sulfate Wet Dry Cycles |
|
KAN Lili, GONG Yawen, WANG Jingrong
|
|
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China
|
| Abstract: |
| Under 10, 20 and 30sulfate wet dry conditioning cycles, crack characteristics, tensile properties of self healing products of engineered cementitious composites(ECC) specimens(curing 7, 28d) pre loaded to strain levels of 10%, 15% and 20% were investigated. The results show that ECC has good self healing effect under different cycles. The maximum width and numbers of residual crack decrease obviously. The maximum width of 7d specimens is reduced from 80μm before healing to 25μm after 10cycles. The maximum width of 28d specimens is reduced from 100μm before healing to 50μm after 30cycles. After self healing, the uniaxial tensile strain capacity of more than 67% specimens approached or exceeded the virgin specimen experienced the same cycles. Ultimate strength of 7d specimens recovered above 75% and 131% for 28d specimens. Layered CaCO3 crystals are the major self healing products. |
| Key words: engineered cementitious composite(ECC) crack self healing sulphate attack wet dry cycle |
