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硅酸盐通报 ›› 2023, Vol. 42 ›› Issue (11): 3878-3883.

所属专题: 水泥混凝土

• 水泥混凝土 • 上一篇    下一篇

长期浸泡作用下风积沙混凝土微观特性研究

朱遂军1, 汪金满1, 王想想1, 杨强斌2, 李根峰2, 杨效田3   

  1. 1.甘肃省第五建设集团有限责任公司,天水 741000;
    2.重庆文理学院土木工程学院,重庆 402160;
    3.兰州理工大学材料学院,兰州 730050
  • 收稿日期:2023-06-15 修订日期:2023-07-11 出版日期:2023-11-15 发布日期:2023-11-22
  • 作者简介:朱遂军(1967—),男,高级工程师。主要从事建筑施工技术的研究。E-mail:740787250@qq.com
  • 基金资助:
    重庆市自然科学基金(CSTC2021JCYJ-BSH0230)

Microscopic Characteristics of Aeolian Sand Concrete under Long Term Immersion

ZHU Suijun1, WANG Jinman1, WANG Xiangxiang1, YANG Qiangbin2, LI Genfeng2, YANG Xiaotian3   

  1. 1. Gansu Fifth Construction Group Co., Ltd., Tianshui 741000, China;
    2. School of Civil Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China;
    3. School of Materials, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2023-06-15 Revised:2023-07-11 Online:2023-11-15 Published:2023-11-22

摘要: 以风积沙混凝土为研究对象,采用核磁共振、场发射扫描电子显微镜及能谱仪观测不同风积沙掺量及不同浓度硫酸盐侵蚀作用下混凝土的微观孔隙结构、微观形貌及产物特征。结果表明:随着风积沙掺量增加,风积沙混凝土抗压强度先增强后减弱,孔隙率先降低后增加,风积沙掺量为40%(质量分数)时力学性能最好;随着硫酸镁浓度的增加以及侵蚀周期的延长,风积沙混凝土相对动弹性模量先增加后降低;当硫酸镁浓度为3.5%、风积沙掺量为40%时,风积沙混凝土浸泡360 d时仍满足标准要求,此时风积沙混凝土孔隙率为2.553%,其中少害及有害孔占比达到63.8%,且产生较多针棒状钙矾石;当硫酸镁浓度为5.0%(质量分数)时,孔隙率增加至2.879%,少害及有害孔比例降低至57.3%,钙矾石富集程度进一步增加。

关键词: 风积沙混凝土, 相对动弹性模量, 风积沙掺量, 硫酸镁浓度, 孔隙率, 钙矾石

Abstract: Taking aeolian sand concrete as research object, the micro-pore structure, micro-morphology and product characteristics of concrete under different aeolian sand content and different concentration of sulfate erosion were observed by nuclear magnetic resonance, field emission scanning electron microscope and energy spectrometer. The results show that with the increase of aeolian sand content, the compressive strength of aeolian sand concrete increases first and then decreases, and the porosity decreases first and then increases. When the content of aeolian sand is 40% (mass fraction), the mechanical properties are the best. With the increase of magnesium sulfate concentration and the extension of erosion period, the relative dynamic elastic modulus of aeolian sand concrete increases first and then decreases. When the concentration of magnesium sulfate is 3.5% and the content of aeolian sand is 40%, the aeolian sand concrete still meets the standard requirements after soaking for 360 d. At this time, the porosity of aeolian sand concrete is 2.553%, of which the proportion of less harmful and harmful pores reaches 63.8%, and more needle-like ettringite is produced. When the concentration of magnesium sulfate is 5.0% (mass fraction), the porosity increases to 2.879%, the proportion of less harmful and harmful pores decreases to 57.3%, and the enrichment degree of ettringite further increases.

Key words: aeolian sand concrete, relative dynamic elastic modulus, aeolian sand content, magnesium sulfate concentration, porosity, ettringite

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