Study on simultaneous heat and mass tranfer in concrete at elevated temperature

高温下混凝土同时传热传质研究

• 批准号: 10650555
• 负责人: NUMAO Tatsuya
• 金额: $ 1.86万
• 依托单位: IBARAKI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650555/
• 关键词: concrete; heating; temperature; humidity; heat conduction; moisture diffusion; material properties; 水分移動; 熱移動; モルタル

In this study, experiments and analysis were carried out to investigate the phenomena of simultaneous heat conduction and moisture diffusion in concrete at elevated temperatures.Material properties of concrete for these phenomena were studied experimentally. Furthermore, analytical studies were carried out to describe the drying process of heated concrete at elevated temperature.As the results of the experimental studies, influence of moisture content and temperature on these material properties were estimated. Especially, it was shown that heat conduction, specific heat, and specific gravity of concrete are mainly affected by moisture condition, and that the sorption isotherm and moisture conduction are significantly influenced not only by relative humidity but also by temperature.Diffusion coefficient was discussed by using the results of the sorption isotherm and moisture conduction. The diffusion coefficient of cementitious material is influenced by temperatures, and it's tendency at temperature 70 degree C is remarkably different from at 20 degree C.Simultaneous heat and mass transfer process in concrete can be simulated by separating the phenomenon into two processes and by means of finite element method.

本研究针对高温下混凝土中同时发生的热传导和水分扩散现象进行了实验和分析，并对这些现象下混凝土的材料性能进行了实验研究。此外，本文还对高温下混凝土的干燥过程进行了分析研究，并根据试验研究结果估算了含水率和温度对这些材料性能的影响。研究表明，混凝土的导热系数、比热和比重主要受湿度条件的影响，吸附等温线和导湿系数不仅受相对湿度的影响，还受温度的影响，并利用吸附等温线和导湿系数的结果讨论了扩散系数。水泥基材料的扩散系数受温度的影响，在70 ℃和20 ℃时的变化趋势明显不同。将混凝土中的热质传递过程分解为两个过程，采用有限元法模拟混凝土中的热质传递过程。

项目成果

沼尾達弥: "セメント硬化体中の湿気移動に関する基礎的研究"日本建築学会大会学術講演会概要集. A-1. 1119-1120 (1999)

Tatsuya Numao：“硬化水泥中水分运动的基础研究”日本建筑学会会议摘要 A-1（1999 年）。

T. Numao and K. Fukuzawa: "Fundamental Study on Moisture Migration in Hardened Cement Paste and Mortar"Summaries of technical papers of annual meeting of the AIJ. A-1. 1119-1120 (1999)

T. Numao和K. Fukuzawa：“硬化水泥浆体和砂浆中水分迁移的基础研究”AIJ年会技术论文摘要。

T. Numao: "Infuluence of temperature on moisture difusion in Hardened Cement Paste and Mortar"Proceedings of the 27th JUCC Congress on Cement and Concrete. (be in press). (2000)

T. Numao：“温度对硬化水泥浆和砂浆中水分扩散的影响”第 27 届 JUCC 水泥和混凝土大会论文集。

早川隆之: "セメント硬化体の脱着吸着等温泉に関する基礎研究"土木学会第54回年次学術講演会. V. 184-185 (1999)

Takayuki Hayakawa：“硬化水泥体的解吸和吸附等温泉的基础研究”日本土木工程学会第54届学术年会V.184-185（1999）。

沼尾達弥: "セメント硬化体の水分移動に及ぼす温度の影響"第27回セメント・コンクリート研究討論会 論文報告集. (印刷中).

Tatsuya Numao：“温度对硬化水泥中水分运动的影响”第 27 届水泥和混凝土研究会议论文集（正在出版）。