| 摘要: |
| 开展了再生粗骨料取代率、粉煤灰掺量和再生粗骨料初始含水率对再生混凝土吸湿过程影响的试验研究.结果表明：再生粗骨料取代率为25%的混凝土毛细吸水系数和湿度响应速率均为最小，取代率为0%、50%、75%、100%的混凝土毛细吸水系数和湿度响应速率依次增大；粉煤灰掺量为10%的混凝土毛细吸水系数和湿度响应速率均为最小，掺量为0%、20%、30%的混凝土毛细吸水系数和湿度响应速率依次增大；混凝土的毛细吸水系数和湿度响应速率均随再生粗骨料初始含水率的增大而增大；在湿度响应过程的早期，3种影响因素对混凝土湿度响应的影响更大，随着湿度响应的进行，该影响逐渐减小，且随着粉煤灰掺量和再生粗骨料初始含水率的增大，不同时段的混凝土湿度响应速率差距增大.基于混凝土传质过程的基本理论，利用试验数据计算出不同试验条件下再生混凝土的湿气扩散系数，进而建立了再生混凝土湿度响应的预测模型. |
| 关键词: 粉煤灰 再生混凝土 湿度响应 毛细吸水系数 湿气扩散系数 预测模型 |
| DOI：10.3969/j.issn.1007-9629.2022.03.005 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金资助项目（51408192）；河海大学中央高校基本科研业务费专项资金项目（B200202232） |
|
| Moisture Absorption Process and Prediction Model of Recycled Concrete Mixed with Fly Ash |
|
JIANG Jianhua, WU Qi, FU Yongquan, LIN Mingyi, SUI Yuan
|
|
College of Civil and Transportation Engineering， Hohai University， Nanjing 210024，China
|
| Abstract: |
| The effects of replacement ratio of recycled coarse aggregate （RCA）， fly ash content and initial moisture content of RCA on the moisture absorption process of recycled concrete were studied by experiments. The results show that the capillary water absorption coefficient and humidity response rate of concrete with the 25% replacement rate of RCA are the smallest， and those of concrete with a replacement rate of 0%， 50%， 75%， 100% increase in above rate sequence. The capillary water absorption coefficient and humidity response rate of concrete with the fly ash content of 10% are the smallest， and those of concrete with the fly ash content of 0%， 20%， 30% also increase in above rate sequence. The capillary water absorption coefficient and humidity response rate of concrete increase with the increase of initial moisture content of RCA. In the early stage of the humidity response， the three influencing factors have a greater effect on the concrete humidity response. As the humidity response progresses， the effect gradually decreases. And with the increase of fly ash content and initial moisture content， the difference in the humidity response rate of concrete in different periods increases. Finally， based on the basic theory of the mass transfer in concrete， the moisture diffusion coefficient of recycled concrete under different test conditions is calculated by using the experimental data. Then， the prediction model of the humidity response of recycled concrete is established. |
| Key words: fly ash recycled concrete humidity response capillary water absorption coefficient moisture diffusion coefficient prediction model |
