- 摘 要
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（1 清華大學土木工程系， 北京 100084； 2 中國寰球工程公司， 北京 100029）
［摘要］通過給定配合比混凝土的低溫劈拉試驗，考察混凝土不同低溫作用工況下的受拉性能變化規(guī)律。結果表明，不同低溫下混凝土立方體試件劈拉破壞形態(tài)相似；混凝土低溫受拉強度離散性雖較大，但基本經歷損傷階段、快速增長階段和平穩(wěn)波動階段。約-10℃時混凝土受拉強度達到極小值，相對常溫降幅達5-7%；約-120℃時達到極大值，相對常溫增幅達42-6%。隨溫度降低，混凝土拉壓比減小、脆性增強。根據試驗結果和已有的研究結果擬合的混凝土低溫相對受拉強度計算公式可為工程實踐提供參考。
［關鍵詞］混凝土； 超低溫； 受拉強度； 試驗
中圖分類號：TU528-1文獻標識碼：A文章編號：1002-848X(2016)13-0086-04
Experimental study on tensile strength of concrete exposed to cryogenic temperature
Shi Xudong1, Ju Yi1, Ma Chi1, Zheng Jianhua2, Zhang Tianshen1
（1 Department of Civil Engineering, Tsinghua University, Beijing 100084， China；2 China Huanqiu Contracting & Engineering Corp, Beijing 100029， China）
Abstract:Through the low temperature splitting test on concrete given mix proportion, the change law of concrete tensile mechanical properties was investigated with different low temperature conditions. The results show that under different low temperature conditions, splitting tensile failure patterns of concrete cube specimens are similar; although low-temperature tensile strength of concrete has large discreteness, it basically experiences damage stage, rapid growth stage and steady fluctuation stage. The tensile strength of concrete reached a minimum value at about -10℃, and the tensile strength drops 5-7% compared with that at normal temperature; at about -120℃, the tensile strength reaches the maximum value with the increase of 42-6% compared with that at normal temperature. With the decrease of temperature, the ratio of tension and compression of concrete decreases, and the brittleness increases. According to the test results and the existing research results, the calculation formula of the relative tensile strength of concrete under low temperature can provide reference for engineering practice.
Keywords:concrete; cryogenic temperature; tensile strength; experiment
*國家自然科學基金項目（51078204），中國寰球工程公司科技研發(fā)課題（60010-1904-CA-BL-003）。
作者簡介：時旭東，博士，教授，博士生導師，Email：shixd@mail.tsinghua.edu.cn。
