Evaluation of Bentonite-Fly Ash Mix for Its Application in Landfill Liners
Evaluation of Bentonite-Fly Ash Mix for Its Application in Landfill Liners
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DOI：
10.1520/jte104161
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发表时间：
2012-04
影响因子：
1.2
通讯作者：
M. Younus;S. Sreedeep
中科院分区：
文献类型：
--
作者：
M. Younus;S. Sreedeep
需要压实的填埋场衬垫，以尽量减少有害污染物向周围地质环境和地下水的迁移。这主要是通过将压实衬层的水力传导率限制在10−7 cm/s的允许限度内来实现的。对于衬里中使用的地质材料，重要的是要确定适当的压实参数范围（含水量和干容重），以确保水力传导性和强度特性在安全范围内。在文献中没有太多的研究来指定这样一个范围的蒙脱石-粉煤灰混合物。无粘性粉煤灰的掺入提高了膨润土的强度，降低了膨润土的收缩性能，但同时也提高了膨润土的导水率。因此，对于不同的膨润土-粉煤灰混合物，确定满足所需的水力传导性和强度范围的含水量和干单位重量的范围是至关重要的。目的是确定能够最大限度地利用粉煤灰的膨润土-粉煤灰混合物，这从环境角度来看是有利的。不同的压实混合料的性能评价已完成使用的两个参考参数的导水率和无侧限抗压强度。这项研究清楚地表明，实用的膨润土粉煤灰混合物作为压实的垃圾填埋场衬垫。基于这些结果，可以注意到，高达70重量%的飞灰可以与膨润土混合，以满足压实的垃圾填埋场衬垫的要求。
Compacted landfill liners are required to minimize the migration of harmful contaminants to the surrounding geoenvironment and groundwater. This is mainly achieved by restricting hydraulic conductivity of the compacted liners within a permissible limit of 10−7 cm/s. For geomaterials used in liners, it is important to determine the appropriate range of compaction parameters (water content and dry unit weight) that would ensure hydraulic conductivity and strength characteristics within safe limits. There are not many studies in the literature for specifying such a range for bentonite-fly ash mixes. The addition of cohesionless fly ash would improve the strength and reduce the shrinkage behavior of bentonite but at the same time would increase the hydraulic conductivity. Therefore, it is of utmost importance to determine the ranges of water content and dry unit weight for different bentonite-fly ash mixes that would satisfy the desired ranges of hydraulic conductivity and strength. The objective is to identify the bentonite-fly ash mix that enables maximum use of fly ash, which is advantageous from an environmental perspective. The performance evaluation of different compacted mixes has been done using hydraulic conductivity and unconfined compressive strength as the two reference parameters. The study clearly demonstrates the utility of a bentonite-fly ash mix as a compacted landfill liner. On the basis of the results, it can be noted that up to 70 % by weight of fly ash can be mixed with bentonite for satisfying the requirements of compacted landfill liners.