掺合料混凝土早龄期拉伸徐变模型研究与仿真应用  

Study on tensile creep model of admixture concrete at early ages and its simulation application

作　　者：郭磊[1] 

机构地区：[1]华北水利水电大学水利学院,河南郑州450045

出　　处：《混凝土》2016年第4期68-71,共4页Concrete

基　　金：国家自然科学基金资助项目(51109081;51309101);河南省教育厅科学技术研究重点项目(12A570002);水利部公益性行业科研专项经费项目(201301025)

摘　　要：针对目前掺合料混凝土缺乏关于早龄期拉伸徐变模型及仿真研究的问题,依据现有徐变规律及适当假设,构建拉伸徐变系数基本式,并以复合指数式作为基本式的参考模型,以掺量为因子建立掺合料影响函数,提出以影响函数的c值定量表征掺合料对混凝土拉伸徐变的作用与敏感性。然后利用基准混凝土与粉煤灰、矿渣、硅粉以及聚丙烯纤维等掺合料混凝土的拉伸徐变试验成果,拟合模型,结果表明拟合相关性佳,且模型简单易用,可用于仿真研究中,同时通过c值,定量说明了粉煤灰、矿渣、硅粉及聚丙烯纤维对混凝土拉伸徐变呈现的差异作用。最后采用该模型对某已建混凝土工程进行拓展仿真应用,结果表明考虑拉伸徐变能有效改善表面拉应力,缓解昼夜温差的不利影响。Aiming at the insufficient research of prediction mode and simulation of admixture concrete tensile creep at early age, the basic function of tensile creep coefficient was built by means of trend analysis of concrete creep and reasonable assumption. And compound exponential function was used as reference model of the basic function when the admixture influence model is built in factor of mix amount. Then, the effect and sensitivity of admixture in concrete can be characterized by c value of admixture influence model. On this basis, the model was verified by the matched experiments including datum concrete, fly ash concrete, slag concrete, silica fume concrete, and polypropylene fiber concrete.The model fitting results show that this prediction model is simple, practical, with better accuracy, and it can be applied to simulation. Finally this prediction model is further used to a constructed concrete project, the simulation re- suits show that concrete tensile creep at early age can reduce the surface tension value and alleviate the adverse effects of temperature difference between day and night.

关 键 词：混凝土 掺合料 拉伸徐变 预测模型 早龄期 拉应力 

分 类 号：TU528.01[建筑科学—建筑技术科学]