| 摘要: |
| 为了研究不同养护温度条件下蒸养混凝土断裂性能的变化规律，开展了养护温度为20、45、60、80、95 ℃的混凝土三点弯曲梁断裂试验.基于双K断裂理论，分析了不同养护温度下蒸养混凝土的断裂性能，探讨了高温养护条件下混凝土损伤因子与其断裂韧度损失率之间的关系.结果表明：45 ℃养护条件下与20 ℃养护条件下的混凝土力学性能和断裂性能基本相同；养护温度大于45 ℃后，随着养护温度升高，高温导致的热损伤效应增强，试件的起裂韧度、失稳断裂韧度、断裂能和特征长度均呈下降趋势；采用弹性模量或抗压强度定义的强度损伤因子与断裂韧度损失率具有较好的相关性.研究成果可为蒸养混凝土断裂参数研究提供依据. |
| 关键词: 养护温度 蒸养混凝土 断裂性能 损伤因子 |
| DOI：10.3969/j.issn.1007-9629.2021.06.006 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金重点资助项目（51739008）；国家重大科研仪器研制项目（51527811） |
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| Fracture Properties of Steam-Cured Concrete under Different Curing Temperatures |
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LOU Benxing1, HU Shaowei2, FAN Xiangqian1, YE Yuxiao1, WANG Yamin1
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1.Nanjing Hydraulic Research Institute， Nanjing 210029， China;2.College of Civil Engineering， Chongqing University， Chongqing 400045， China
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| Abstract: |
| To study the fracture properties of steam-cured concrete under different curing temperatures， three-point bending （TPB） specimens at different curing temperatures （20， 45， 60， 80 and 95 ℃） were tested. Based on the double-K fracture theory， the effects of curing temperatures on the mechanical and fracture properties of the steam-cured concrete were analyzed， and the relationship between the damage factor of concrete and the loss ratio of fracture toughness was discussed. The results indicate that the mechanical properties and fracture properties of concrete under 45 ℃ curing condition are consistent with that under 20 ℃ curing condition； when the curing temperature is higher than 45 ℃， the thermal damage effect enhances， and the fracture parameters of the specimen（ including initial fracture toughness， unstable fracture toughness， fracture energy and characteristic length ）decrease with the increase of curing temperature； a good correlation between the loss ratio of fracture toughness and the strength damage factor defined by elastic modulus or compressive strength is observed， which provide a basis for the fracture parameters of steam-cured concrete. |
| Key words: curing temperature steam-cured concrete fracture property damage factor |
