Soil Stabilization by Calcium Carbide Residue and Fly Ash
Soil Stabilization by Calcium Carbide Residue and Fly Ash
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DOI：
10.1061/(asce)mt.1943-5533.0000370
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发表时间：
2012-02-01
影响因子：
3.2
通讯作者：
Chinkulkijniwat, Avirut
中科院分区：
文献类型：
--
作者：
Horpibulsuk, Suksun;Phetchuay, Chayakrit;Chinkulkijniwat, Avirut
电石渣(CCR)和飞灰(FA)分别是乙炔气厂和发电厂产生的废气。CCR和FA的混合物产生一种胶凝材料，因为CCR含有大量的Ca(OH)(2)，而FA是一种火山灰材料。本文研究了使用这种胶凝材料(CCR和FA的混合物)来提高泰国东北部有问题的粉质粘土强度的可能性。研究中涉及的影响因素有含水率、粘结剂含量、CCR/FA比和养护时间。并对强度发展的控制机制进行了阐述。通过无侧限压缩试验研究了混凝土的强度发展。利用扫描电子显微镜和热重分析对材料的微观结构进行了研究，以了解影响因素对材料微观结构的影响。强度和微观结构研究表明，CCR的输入降低了比重和土塑性，从而降低了最大干容重和水敏性。稳定粉质粘土的最大强度出现在不同粘结剂含量、CCR：FA比和养护时间的大致最佳含水率下。在特定的固化时间内，强度的提高可分为三个区域：活性、惰性和劣化。在活化区，对于所有CCR/FA比，随着CCR含量的增加，其强度显著增加。FA(CCR替代物)的投入不能显著促进强度发展，因为在火山灰反应中，所有输入的Ca(OH)(2)都被土壤中的天然火山灰材料消耗掉。这个活动区可以从Ccr固定点确定，这一点只需通过指数测试即可获得。当CCR含量超过活动区时，FA(CCR置换)的投入是有效的，因为土壤中没有足够的天然火山灰物质与Ca(OH)(2)反应。本文提出的控制强度发展的可能机理可应用于其他由富Ca(OH)(2)材料和火山灰材料制成的不同胶凝材料稳定的粘性土，以解释和分析强度发展。对合理剂量方法学的进一步研究将是基础。DOI：10.1061/(ASCE)MT.1943-5533.0000370。(C)2012年美国土木工程师学会。
Calcium carbide residue (CCR) and fly ash (FA) are both waste products from acetylene gas factories and power plants, respectively. The mixture of CCR and FA produces a cementitious material because CCR contains a lot of Ca(OH)(2), while FA is a pozzolanic material. This paper investigates the possibility of using this cementitious material (a mixture of CCR and FA) to improve the strength of problematic silty clay in northeast Thailand. The influential factors involved in this study are water content, binder content, CCR: FA ratio, and curing time. The mechanism controlling the development of strength is also illustrated. Strength development is investigated using the unconfined compression test. A microstructural study using a scanning electron microscope and thermal gravity analysis is performed to understand the microstructural changes that accompany the influential factors. Both strength and microstructural investigations reveal that the input of CCR reduces specific gravity and soil plasticity; thus, the maximum dry unit weight and water sensitivity. The maximum strength of the stabilized silty clay occurs at approximately the optimum water content for different binder contents, CCR: FA ratios, and curing times. The improvement in strength for a particular curing time is classified into three zones: active, inert, and deterioration. In the active zone, the strength increases remarkably with the CCR content for all CCR: FA ratios. The input of FA (CCR replacement) does not significantly enhance strength development because all input Ca(OH)(2) is consumed by the natural pozzolanic material in the soil in the pozzolanic reaction. This active zone can be determined from the CCR fixation point, which is simply obtained from the index test. The input of FA (CCR replacement) is effective when the CCR content is in excess of the active zone, where insufficient natural pozzolanic material in the soil is present to react with the Ca(OH)(2). The possible mechanism controlling strength development that is presented in this paper can be applied to the other clayey soils stabilized with different cementitious materials, produced from Ca(OH)(2)-rich materials and pozzolanic materials, to explain and analyze strength development. Further study on a development of rational dosage methodology will be fundamental. DOI: 10.1061/(ASCE)MT.1943-5533.0000370. (C) 2012 American Society of Civil Engineers.