On the viscous behavior of cement mixtures with clay, sand, lime and bottom ash for jet grouting
On the viscous behavior of cement mixtures with clay, sand, lime and bottom ash for jet grouting
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DOI：
10.1016/j.conbuildmat.2015.05.072
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发表时间：
2015-09-15
影响因子：
7.4
通讯作者：
Gullu, Hamza
中科院分区：
文献类型：
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作者：
Gullu, Hamza
喷射灌浆是边缘土改良中流行的最新技术之一（即，软质细粒或松散的粗粒），大多可在工程结构的施工现场获得。由于这种技术，土壤改良的性能主要取决于新鲜灌浆混合物的流动能力。如果没有令人满意的流动性能，喷射灌浆柱的硬化材料就不可能获得理想的结果。本文从流变特性（粘度、屈服应力）和流变行为（剪切应力-剪切速率流动曲线）两个方面，对比研究了不同稳定剂对高压喷射灌浆水泥基浆液粘度特性的影响。稳定剂包括粘土、砂、石灰和底灰，它们以各种比例存在，用量为粘结剂干重的0%至100%。通过对每个稳定剂比率进行10次重复的流变仪测试来进行广泛的实验研究。使用质量控制图的统计分析，确定了10个重复样本中的合格检测，并在研究的整个调查过程中使用。使用多重比较的统计学显著性分析（Dunnett检验）确定稳定剂与剂量率对天然骨水泥的影响。从研究结果中观察到，所使用的稳定剂对混合物的流动能力的贡献主要取决于它们的剂量率。砂、石灰和底灰的掺量分别为30%、40%和50%时，由于多重比较（p > 0.05），对水泥的流变特性没有显著影响，可供实际应用。从稳定剂组合的尝试中也获得了对天然水泥的类似益处。剪切应力-剪切速率曲线的流变行为由于稳定剂夹杂物的存在而产生具有各种非线性响应的非牛顿运动，这主要导致假塑性行为，然后是屈服假塑性行为。对流变特性影响不显著的稳定剂的潜在剂量率也产生与天然水泥相同的流变行为（除了石灰夹杂物），代表良好的稠度以支持其使用。从模型比较（即，Casson，Herschel-Bulkley）与实测剪切应力-剪切速率曲线进行了比较，发现Herschel-Bulkley模型比Casson模型更能准确地描述流变行为。满意度模型可以帮助查询混合物组成中的复杂关系。本文的尝试反映了所用稳定剂对天然水泥的影响，并为喷射灌浆在流变学方面的应用提供了有希望的发现。从环境角度来看，对底灰使用的研究结果也可能有助于解决其处置问题。(C)2015爱思唯尔有限公司版权所有。
Jet grouting is one of the newest technologies being popular in the improvement of the marginal soils (i.e., soft fine-grained or loose coarse grained) mostly available at the construction sites of engineering structures. The performance of soil improvement due to this technique is primarily dependent on the flow abilities of the fresh grout mixtures. Without satisfactory flow properties, it is unlikely that the hardened material of jet grout column could be achieved with desirable results. This paper investigates the viscous properties of cement based grout mixtures with different stabilizers comparatively, for jet grouting, in the point of rheological characteristics (viscosity, yield stress) and rheological behaviors (the flow curve of shear stress-shear rate). The stabilizer inclusions are clay, sand, lime and bottom ash in various proportions at the dosage rates from 0% to 100%, by dry weight of binder. An extensive experimental study was carried out by conducting the rheometer tests with ten replicates for each stabilizer rate. Using statistical analysis of quality control charts, satisfactory tests within the ten replicates have been determined and employed throughout their investigations in the study. The effect of stabilizer versus dosage rates on native cement was determined using the statistical significance analysis of multiple comparisons (Dunnett test). It is observed from the results of study that the employed stabilizers relatively have the potential of contributions to flow capability of the mixtures primarily dependent upon their dosage rates. The proportions up to the dosages rates of 30%, 40% and 50% respectively for the separate additions of sand, lime and bottom ash, which do not show statistically significant changes on the rheological characteristics of native cement, due to the multiple comparisons (p > 0.05), could be potentially offered for practice. Similar benefits on the native cement have also been obtained from the attempts of stabilizer combinations. The rheological behavior of shear stress-shear rate curves due to the stabilizer inclusions generate a non-Newtonian motion with various nonlinear responses, which dominantly result in pseudo-plastic behavior followed by the one of yield-pseudoplastic. The potential dosage rates of stabilizers that provide insignificant effects on the rheological characteristics are also produce same rheological behaviors with the native cement (except lime inclusions) representing a good consistency to support their usage. From the model comparisons (i.e., Casson, Herschel-Bulkley) with the measured shear stress-shear rate curves resulted in yield-pseudoplastic behavior, it is found that the Herschel-Bulkley model describes the rheological behavior more properly as compared with the Casson model. The satisfactory model could be helpful for querying the complex relations in the mixture compositions. The attempt presented in this work reflects the influences of the employed stabilizers on native cement with the promising findings for jet grouting in the linkage of rheology. The findings on the usage of bottom ash could also contribute to its disposal problem in the environmental point of view. (C) 2015 Elsevier Ltd. All rights reserved.