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硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (2): 676-682.

所属专题: 道路材料

• 道路材料 • 上一篇    下一篇

SAP内养生路面混凝土收缩性能及力学性能研究

劳家荣1, 黄忠财1, 郭寅川2, 陈琳3, 申爱琴2, 杨景玉2   

  1. 1.广西桂龙高速公路有限公司,南宁 530011;
    2.长安大学,教育部特殊地区公路工程重点实验室,西安 710064;
    3.广西崇瑞高速公路有限公司,南宁 530011
  • 收稿日期:2020-10-19 修回日期:2020-12-03 出版日期:2021-02-15 发布日期:2021-03-10
  • 作者简介:劳家荣(1974—),男,高工。主要从事路基路面工程方面的研究。E-mail:geloushaoyu@126.com

Shrinkage and Mechanical Properties of Internal Curing Pavement Concrete with SAP

LAO Jiarong1, HUANG Zhongcai1, GUO Yinchuan2, CHEN Lin3, SHEN Aiqin2, YANG Jingyu2   

  1. 1. Guangxi Guilong Expressway Co., Ltd., Nanning 530011, China;
    2. Key Laboratory for Special Area Highway Engineering of Ministry, Xi'an 710064, China;
    3. Guangxi Chongrui Expressway Co., Ltd., Nanning 530011, China
  • Received:2020-10-19 Revised:2020-12-03 Online:2021-02-15 Published:2021-03-10

摘要: 超吸水性树脂(SAP)作为一种内养生材料,对混凝土力学性能、收缩性能等均具有显著改善作用,在公路混凝土路面中具有十分重要的应用价值。本文通过对混凝土力学性能、收缩变形及内部相对湿度进行研究,并通过SEM对SAP内养生混凝土内部微观形貌、裂缝特征进行分析。结果表明:SAP的加入能显著降低混凝土毛细孔隙间的范德华力,抑制混凝土的收缩应变;并能够在混凝土内部湿度下降时及时对混凝土进行水分补偿,使得其28 d内的相对湿度可保持在90%以上;SAP参数(目数及掺量)对混凝土抗弯拉强度的影响较大,其中100~120目(150~120 μm)SAP对混凝土抗弯拉强度的提升作用最好;SAP的掺入可以提高水泥水化程度,生成更多的水化产物,改善混凝土内部结构,提升其密实性,并降低混凝土内部微裂纹长度及宽度,从而在一定程度上提高混凝土内部相对湿度,进而提升混凝土的力学强度,并减少其收缩变形。

关键词: 超吸水性树脂, 内养生混凝土, 收缩性能, 相对湿度, 力学性能, 微观形貌

Abstract: Super-absorbent polymer (SAP), as a kind of internal curing material, has very important value when applied to highway concrete pavement, and it significantly improves the mechanical properties and shrinkage properties of concrete. In this paper, the mechanical properties, shrinkage deformation and internal relative humidity of concrete were studied, and the internal micro morphology and crack characteristics of SAP curing concrete were analyzed by SEM. The results show that the addition of SAP significantly reduces the shrinkage strain of concrete, and limits the volume expansion of concrete that gradually increases with age. And it timely compensates the concrete moisture when the internal humidity of the concrete drops, so that the relative humidity within 28 d can be kept above 90%. SAP parameters (mesh and content) have a greater influence on the flexural tensile strength of concrete, among which 100 mesh to 120 mesh (150 μm to 120 μm) SAP has the best effect on the improvement of flexural tensile strength. The incorporation of SAP increases the degree of cement hydration, generates more hydration products, improves the internal structure of concrete, increases the compactness of concrete, and reduces the length and width of micro-cracks inside the concrete, so SAP improves the mechanics strength, shrinkage performance and durability of concrete to a certain extent.

Key words: super-absorbent polymer, internal curing concrete, shrinkage property, relative humidity, mechanical property, microstructure

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