碳酸盐岩骨料中碳质物成因及定量检测方法研究

Research on cause of formation and quantitative determination of carbonaceous materials in carbonate aggregate

骨料中碳质物的类型和含量对混凝土强度有直接影响,但目前大部分研究仅能提供碳质物含量高低的粗略估计或定性结果,对碳质物在岩石中的赋存形态和石墨化程度的研究成果也很有限。通过野外观测、显微镜下岩相学观察以及激光拉曼光谱仪分析,查明了乌东德水电站施期料场碳酸盐岩骨料中碳质物的分布特征和石墨化程度,探讨了碳质物的成因;将总有机碳(TOC)定量检测方法运用于原岩、骨料和混凝土碳质物含量的测定,通过不同型号仪器测试结果的对比,发现该方法具有低检出限、高精度的特点,可适用于有机碳含量很低的骨料样品检测,弥补了传统定性检测方法的不足。研究结果还表明:拉曼光谱分析可快速获得碳质物石墨化程度的准确信息,而TOC分析技术可精确测定碳质物的含量,将二者有机结合,可提供骨料中碳质物产状、成因和演化历史的独特信息,可为开展骨料中碳质物对混凝土性能影响的实验研究提供重要科学数据。

The component and content of carbonaceous material(CM)in aggregatemay strongly influence thestrength of concrete.However,most previous researches only providerough estimates or qualitative results on the content of CM,while constraints on the spatial distribution and the graphitization degree of the CM are generally lacking.In this paper,we analyzed the distribution and graphitization degree of CM in carbonate aggregate of the quarry in Wudognde Hydropower Station through field reconnaissance,petrographic observation under micoscope andlaser Raman analysis,and discussed thecause of formation of the CM.Furthermore,the total organic carbon(TOC)quantitative detection method was applied to the determination of the carbon content of raw rock,aggregate and concrete.Through the comparison of the test results from different types of instruments,it was found that this method had the characteristics of low detection limit and high precision,which could be applied to the detection of aggregate samples with low organic carbon content,making up for the shortcomings of traditional qualitative detection methods.The results also showed that Raman spectroscopy can quickly obtain accurate information of the graphitization degree of the CM,and TOC analysis technology can accurately determine the content of the CM.The organic combination of this two methods can provide unique information about the occurrence,cause of formation and evolution history of carbon materials in aggregates,and provide important scientific data for the experimental study of the influence of carbon materials in aggregates on concrete performance.