Strength Development and Reaction Kinetics in Lime-Treated Clays
Strength Development and Reaction Kinetics in Lime-Treated Clays
复制标题
石灰处理粘土的强度发展和反应动力学
DOI：
10.1061/9780784484012.014
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Chrysochoou, Maria
中科院分区：
文献类型：
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作者：
Ahmadullah, Tasneem;Chrysochoou, Maria
研究了钠基膨润土和高岭石两种纯粘土矿物与消石灰胶凝反应的热力学和动力学。通过对普罗克特压实曲线和7天无侧限抗压强度（UCS）结果的评估，首先对每种矿物的强度发展的最佳含水量（OMC）进行了研究。高岭石粒径对5%消石灰或5%波特兰水泥处理的试件的7天抗压强度影响不大。对于两种粘结剂，对于两种不同粒度的高岭石，观察到最佳干燥含水量产生最高的UCS值。相反，膨润土产生更高的UCS湿的最佳（1.4倍的OMC）的水泥和石灰。石灰混合物长达180-360天的长期强度试验表明，膨润土与8%熟石灰混合后，在400 kPa下固化28天后达到稳定。孔溶液浸提液表明，在相同的时间范围内，pH值从13降至10，然后保持恒定。热重分析（TGA）证实，这一趋势与快速消耗的游离石灰。相反，高岭石的pH值保持在13至180天，并且石灰的自由消耗是逐渐的。高岭石的强度随时间几乎呈线性增长，且增长速率与水合硅酸钙（CSH）的表观生成速率一致。未来的工作包括全孔溶液分析以及用核磁共振（NMR）和X射线衍射（XRD）对固体进行定量分析，以增强TGA数据。将固体和孔隙溶液数据相结合，以获得两种矿物的完整动力学定量模型。
This study reports on the thermodynamics and kinetics of the cementitious reactions between two pure clay minerals (sodium bentonite and kaolinite) and slaked lime. The optimum moisture content (OMC) for strength development was first investigated for each mineral, through an evaluation of both the proctor compaction curves and the 7-day Unconfined Compressive Strength (UCS) results. Particle size of kaolinite was observed to have little influence on the 7-day UCS of specimens treated with 5% slaked lime or 5% Portland cement. A water content dry of optimum was observed to generate the highest UCS values for two different particles sizes of kaolinite, for both the binders. Conversely, bentonite yielded higher UCS wet of optimum (1.4 times the OMC) for both cement and lime. Long-term strength tests for the lime blends up to 180–360 days showed that bentonite mixed with 8% slaked lime plateaued at 400 kPa after 28 days of curing. The pore solution extract indicated that pH dropped from 13 to 10 within the same time frame, then remained constant. The Thermogravimetric analysis (TGA) confirmed that this trend was associated with a rapid consumption of free lime. Conversely, kaolinite maintained a pH of 13 up to 180 days and free consumption of lime was gradual. The strength increased almost linearly with time in kaolinite, and the rate of increase was in step with the apparent rate of calcium silica hydrate (CSH) formation. Future work includes full pore solution analysis as well as quantitative analysis of the solid with Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) to enhance the TGA data. The solid and pore solution data will be combined to obtain a full kinetic quantitative model for the two minerals.
DOI：
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发表时间：
2017
期刊：
影响因子：
--
作者：
N. Maubec;D. Deneele;G. Ouvrard
通讯作者：
G. Ouvrard