VERIFICATION OF COMBINATION USE OF EXPANSIVE AGENT AND LIGHTWEIGHT AGGREGATE ON FATIGUE RESISTANCE OF RC SLAB AND THERMAL STRESS RESTRANT AND ITS UTILIZATION

膨胀剂与轻骨料配合使用对RC板抗疲劳性能及热应力抑制剂的验证及应用

• 批准号: 24656267
• 负责人: KISHI Toshiharu
• 金额: $ 2.58万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Challenging Exploratory Research
• 财政年份: 2012
• 资助国家: 日本
• 起止时间: 2012-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-24656267/
• 关键词: コンクリート; 床版; 疲労; 温度応力; 膨張材; 軽量骨材

It was reported that simultaneous use between expansive agent and artificial lightweight aggregate in cement concrete could restrain thermal stress induced under elevated temperature, and it could also prolong fatigue life of RC slab. In this study measurements of thermal expansion coefficient of specimens and microscopic visual observation around lightweight aggregate were conducted to understand its complicated mechanism. By the experimental investigations two tendencies were suggested as important factors. One is time dependent change of thermal expansion coefficient of this concrete. It is higher than normal concrete at the early age but it becomes small in the longer time. The other is that thermal expansion coefficient of lightweight aggregate is almost half of normal aggregate. Precipitation of additional hydration product at the gap space created around lightweight aggregate due to expansive action was not observed though it was suggested as a possible cause of that mechanism.

在水泥混凝土中同时使用膨胀剂和人工轻骨料，可以抑制高温下产生的热应力，延长RC板的疲劳寿命。本研究通过试样热膨胀系数的测量和轻骨料周围的显微目视观察来了解其复杂的机理。通过实验研究，提出了两种倾向是重要的影响因素。一是混凝土热膨胀系数随时间的变化。龄期早期高于普通混凝土，但龄期越长越小。二是轻骨料的热膨胀系数几乎是普通骨料的一半。由于膨胀作用，在轻骨料周围产生的空隙处没有观察到额外水化产物的沉淀，尽管这被认为是该机制的可能原因。

项目成果

養生温度を変えた膨張コンクリートの一軸引張特性

不同养护温度膨胀混凝土单轴拉伸性能

• 发表时间: 2013
• 作者: Hikaru Iijima;Yuya Sakai;Toshiharu Kishi;飯島光,酒井雄也,岸利治,溝渕利明
• 通讯作者: 飯島光,酒井雄也,岸利治,溝渕利明

Mechanical Performance of expansive concrete in uniaxial tension test with different cement type, age, and curing condition

不同水泥品种、龄期和养护条件下膨胀混凝土单轴拉伸力学性能

• 发表时间: 2013
• 作者: Hikaru Iijima;Yuya Sakai;Toshiharu Kishi
• 通讯作者: Toshiharu Kishi