混凝土2024,Issue(5) :108-116.DOI:10.3969/j.issn.1002-3550.2024.05.019

碳酸盐岩质机制砂石制备高性能自密实混凝土微孔隙结构试验研究

Experimental study on micropore structure of high performance self-compacting concrete prepared by carbonate sand

张著芳 徐桂弘 李振学 段莉 贾萸 刘梓晗
混凝土2024,Issue(5) :108-116.DOI:10.3969/j.issn.1002-3550.2024.05.019

碳酸盐岩质机制砂石制备高性能自密实混凝土微孔隙结构试验研究

Experimental study on micropore structure of high performance self-compacting concrete prepared by carbonate sand

张著芳 1徐桂弘 2李振学 3段莉 2贾萸 2刘梓晗2
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作者信息

  • 1. 贵州省公路工程集团有限公司,贵州 贵阳 550001
  • 2. 贵州理工学院,贵州 贵阳 550000
  • 3. 沧州路桥工程责任有限公司,河北 沧州 061000
  • 折叠

摘要

为了探究高性能自密实混凝土(C80)微孔结构分布特征,采用高分辨率X射线计算机断层扫描试验、AVIZO软件、扫描电镜等方法对碳酸盐质机制砂石自密实混凝土试件内部孔隙结构进行观测分析,主要结论如下:在碳酸盐岩质高性能自密实混凝土内部存在大量的孔隙结构,在10 μm的测试精度范围内,微孔呈现圆形特征,整体圆整度较好.通过SEM扫描电镜观测可知,在高性能混凝土内部存在着微裂隙或贯通的裂隙结构,这些裂隙的宽度在 0.5~2 μm,样品的内部存在 3~10 μm的微小空洞.碳酸盐岩质机制砂自密实混凝土内部的微孔洞进行统计分析,孔洞直径服从三参数正态分布,受试验观测及精度的限制,试验统计结果呈现正偏(高峰偏左)现象,故提出一种"纠正偏峰"方法对统计结果"第三参数C"的计算进行的分析和探讨,结果表明所提出的方法可以快速、客观、较优地确定第三参数,弥补 10 μm以下未统计到的缺失数据及试验样品有限的限制,为检验混凝土内孔洞的分布提供了参考.

Abstract

In order to explore the micropore structure distribution characteristics of high performance self-compacting concrete(C80),high-resolution X-ray computed tomography test,AVIZO software,scanning electron microscopy and other methods were used to observe and analyze the internal pore structure of carbonate mechanism sand and gravel self-compacting concrete specimens.The main conclusions are as follows,there are a lot of pore structures in the carbonate high-performance self-compacting concrete.The pores show circular characteristics and the overall roundness is good within the test accuracy range of 10 μm.By SEM scanning electron microscope observation,it can be seen that there are micro cracks or through cracks in the high performance concrete.The width of these cracks is about from 0.5 μm to 2 μm,and there are from 3 μm to 10 μm tiny voids in the sample.Statistical analysis of micro-pores in carbonate sand self-compacting concrete shows that the diameter of pores follows the normal distribution of three parameters.Limited by experimental observation and accuracy,the statistical results show a positive bias(peak deviation to the left)phenomenon.A method of"correcting peak deviation"is proposed to analyze and discuss the calculation of the"third parameter C"of the statistical results.The results show that the method proposed can determine the third parameter quickly,objectively and optimally,and make up for the limitations of missing data less than 10 μm and limited test samples,which provides a reference for inspecting the distribution of holes in concrete.

关键词

C80高性能自密实混凝土/微孔洞/三参数正态分布/孔径

Key words

C80 high performance self-compacting concrete/micropore/three-parameter normal distribution/aperture

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基金项目

贵州省科技计划(黔科合基础-ZK[2022]重点027)

国家自然科学基金地区科学基金(52268065)

出版年

2024
混凝土
中国建筑东北设计研究院有限公司

混凝土

CSTPCD北大核心
影响因子:0.844
ISSN:1002-3550
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