| 摘要: |
| 针对再生粗骨料黏附砂浆含量高的特点，分析其含量变化与再生粗骨料性能的关系，研究全再生粗骨料混凝土在不同黏附砂浆含量下的抗氯离子侵蚀性能演化规律，界定再生粗骨料黏附砂浆含量的门槛值.研究发现：黏附砂浆含量对再生粗骨料和再生混凝土性能影响很大；随着黏附砂浆含量的增加，再生粗骨料吸水率、开口孔隙率和压碎值线性增大，表观密度线性减小，再生混凝土的3、7、28 d抗压强度出现不同程度的降低，孔隙率则逐渐增大；再生混凝土的氯离子扩散系数、自由氯离子含量和结合氯离子含量均随着黏附砂浆含量的增加而逐渐增大，且氯离子结合能力不断增强；再生混凝土氯离子扩散系数与再生粗骨料的黏附砂浆含量呈二次抛物线关系，在D级和E级氯盐环境下，能满足再生混凝土50 a抗氯离子侵入性指标的黏附砂浆含量最大值分别确定为35.03%和23.01%. |
| 关键词: 再生骨料 再生混凝土 黏附砂浆 氯离子扩散系数 氯离子含量 |
| DOI：10.3969/j.issn.1007-9629.2021.06.013 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金资助项目（51878081，51778272，52108190） |
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| Effect of Attached Mortar Content on Chloride Ion Erosion Resistance of Recycled Concrete |
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CHEN Chunhong1,2, LIU Ronggui1, ZHU Pinghua2, ZANG Xuhang2
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1.Faculty of Civil Engineering and Mechanics， Jiangsu University， Zhenjiang 212013，China;2.Department of Civil Engineering，Changzhou University，Changzhou 213164，China
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| Abstract: |
| Aiming at the characteristics of high attached mortar content of recycled coarse aggregate， the relationship between the variation of its content and the performance of recycled coarse aggregate was analyzed， the evolution rule of chloride ion erosion resistance of fully recycled coarse aggregate concrete under different attached mortar content was studied， and the threshold value of the attached mortar content of recycled coarse aggregate was defined. It is found that the content of attached mortar plays a significant role in the performance of recycled coarse aggregate and recycled concrete. With the increase of attached mortar content， the water absorption rate， opening porosity and crushing value of recycled coarse aggregate increase linearly， while the apparent density decreases linearly. The compressive strength of recycled concrete at 3 d， 7 d and 28 d decreases to varying degrees， and the porosity increases gradually. The chloride ion permeability coefficient， free chloride ion content and binding chloride ion content of recycled concrete increase with the increase of attached mortar content， and the chloride ion binding ability enhances continuously. The chloride penetration coefficient of recycled concrete has a quadratic parabola relation with the attached mortar content of recycled coarse aggregate， and the maximum value of the attached mortar content that meet the anti-chloride ion invasion index of recycled concrete in the environment of grade D and grade E chloride salt for 50 years is 35.03% and 23.01%， respectively. |
| Key words: recycled aggregate recycled concrete attached mortar chloride ion permeability coefficient chloride content |
