土工基础

›› 2018, Vol. 32 ›› Issue (4): 449-452.

• 工程实录 • 上一篇    下一篇

钙质砂中碳酸钙含量测定方法的研究

李小刚1，朱长歧2，张珀瑜1   

  1. （1.桂林理工大学土木与建筑工程学院，广西桂林 541004；2.中国科学院武汉岩土力学研究所，武汉 430071）
  • 收稿日期:2017-09-05 修回日期:2017-09-20 出版日期:2018-08-20 发布日期:2018-08-23
  • 作者简介:李小刚（1993-），男，硕士研究生，研究方向为珊瑚礁岩土力学。

Methods for the Determination of the Calcium Carbonate in Calcareous Sand

LI Xiaogang1, ZHU Changqi2, ZHANG Poyu1   

  1. (1.College of Civil Engineering and Architecture, Guilin University of Technology, Guilin 541004；
    2.Institute of Rock and soil Mechanics, Chinese Academy of Sciences, Wuhan 430071)
  • Received:2017-09-05 Revised:2017-09-20 Online:2018-08-20 Published:2018-08-23

摘要： 钙质砂是一种海洋沉积物，其化学成分主要为碳酸钙，碳酸钙含量是钙质砂区别于一般石英砂的主要指标。按国际通用分类标准规定，当土中碳酸钙含量超过50%时，其力学性质会发生较为显著的变化，因此准确测定土中的碳酸钙含量对准确评价钙质土的工程特性无疑具有重要的意义。采用取自三亚某海滩的砂土为试验土样，比较气量法、EDTA容量法、元素分析仪法和原子吸收光谱法测定碳酸钙含量的差异。结果表明：四种测定方法的试验结果间存在着较为明显的差异，将测定结果与X衍射法测试结果进行对比，发现EDTA滴定法与X衍射法的测定结果相关性最高。综合比较操作难度、测试费用、分析速度和试验精度等指标，认为EDTA容量法较为适合钙质砂中碳酸钙含量的测定。

关键词: 钙质砂, 碳酸钙, 气量法, EDTA容量法, 元素分析仪法, 原子吸收光谱法

Abstract: Calcareous sand is a marine sediment with main component of calcium carbonate. The calcium carbonate content in calcareous sand is a major index that of mechanical properties that is different from those in the quartz sand. In accordance with the general accepted classification standards, when the calcium carbonate content in the calcareous sand is more than 50%, the mechanical properties of the calcareous sand will have significantly different. Therefore, it is important to accurately determine calcium carbonate content in order to accurately evaluate the engineering properties of calcareous soils. The calcareous soil samples were collected from in Sanya, Hainan Province. Four different test methods, namely, comparative gasometric method, EDTA titration, atomic analysis method and atomic absorption spectrometry, were performed to determine the calcium carbonate content in soil samples. The results indicate that test results are very different among all four different methods. Further analysis indicates that the EDTA titration method had the highest correlation with the Xray diffraction method. Comparisons among the test difficulty, cost, analysis speed and test precision and other factors, indicate that the EDTA titration method is more suitable for the determination of calcium carbonate content in calcareous soils.

Key words: Calcareous Sand, Calcium Carbonate Content, Gasometric Method, EDTA Titration, Atomic Analysis Method, Atomic Absorption Spectrometry