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硅酸盐通报 ›› 2023, Vol. 42 ›› Issue (6): 2027-2036.

所属专题: 水泥混凝土

• 水泥混凝土 • 上一篇    下一篇

内养生混凝土力学行为及抗氯离子渗透性能研究

刘玉涛1, 高艺榕1, 马必聪2   

  1. 1.桂林理工大学土木与建筑工程学院,桂林 541004;
    2.广西路桥工程集团有限公司,南宁 530011
  • 收稿日期:2023-03-15 修订日期:2023-03-15 出版日期:2023-06-15 发布日期:2023-06-25
  • 通信作者: 马必聪,高级工程师。E-mail:1374997746@qq.com
  • 作者简介:刘玉涛(1995—),男,硕士研究生。主要从事新型建筑材料、混凝土结构耐久性方面的研究。E-mail:18263978139@163.com
  • 基金资助:
    广西高校中青年教师科研基础能力提升项目(2021KY0338);南宁学院校级科研项目(2022KY166)

Mechanical Behavior and Chloride Penetration Resistance of Internal Curing Concrete

LIU Yutao1, GAO Yirong1, MA Bicong2   

  1. 1. College of Civil and Architecture Engineering, Guilin University of Technology, Guilin 541004, China;
    2. Guangxi Road and Bridge Engineering Group Co., Ltd., Nanning 530011, China
  • Received:2023-03-15 Revised:2023-03-15 Online:2023-06-15 Published:2023-06-25

摘要: 随着我国基础建设的不断推进,对混凝土材料的要求也越来越高,高吸水性树脂(SAP)作为一种新型内养生材料具有重量轻、吸水保水性好、受压后不易脱水等优点,受到越来越多国内外学者的关注。为了探究SAP内养生混凝土力学行为及抗氯离子渗透性能,制备了不同掺量和粒径的SAP混凝土进行试验,并借助核磁共振(NMR)与扫描电子显微镜(SEM)观察与分析SAP混凝土内部微观孔结构。结果发现,掺入SAP明显地降低了混凝土的早期强度,相较于基准组3 d强度最高降低可达25%,但对中后期强度影响较小。SAP的掺入对混凝土内部孔结构的影响明显,随着养护龄期的增长,SAP的内养护作用逐渐发挥,孔隙结构得到明显优化。SAP的掺入提高了混凝土的抗氯离子渗透能力,相较于基准组56 d抗渗性能最高提升38%,通过BP神经网络拟合可以较好地对氯离子扩散系数进行预测。

关键词: 内养生混凝土, 混凝土强度, 孔结构, 耐久性, BP神经网络

Abstract: With the continuous advancement of China’s infrastructure construction, the requirements for concrete materials are becoming higher and higher. As a new type of internal curing material, super absorbent polymer (SAP) possesses the advantages of good water absorption and water retention, light weight and hard to dehydrate after compression, it has attracted more and more attention from scholars at home and abroad. To explore the mechanical behavior and chloride penetration resistance of SAP internal cured concrete, several groups of concrete with different SAP content and particle size were set up, and the internal micro pore structure of SAP concrete was observed and analyzed by means of nuclear magnetic resonance (NMR) and scanning electron microscope (SEM). The results show that the incorporation of SAP material can significantly reduce the early strength of concrete, and the 3 d strength can be reduced by up to 25% compared with the reference group, but the influence on the strength of the middle and later period is not very great. With the addition of SAP, the volume and number of pores in concrete are significantly reduced, and the pore structure is optimized. The addition of SAP improves the chloride penetration resistance of concrete, the 56 d impermeability is improved by 38% compared with the reference group. The chloride migration coefficient can be well predicted by BP neural network fitting.

Key words: internal curing concrete, strength of concrete, pore structure, durability, BP neural network

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