SGER: Are High Carbon Fly Ashes (HCFAS) Effective Stabilizers for Soft Organic Soils?

胶凝C级飞灰和其他胶结剂已被发现是软无机土的非常有效的稳定剂，但对软有机土的稳定基本上无效。然而，PIS开发的初步试验数据表明，胶凝高碳飞灰(HCFA)可以有效地稳定软有机土壤，即有机碳含量为3%的飞灰。本试验的目的是探索用HCFAs加固软有机土的可行性。这个概念是新的，因为一个长期悬而未决的问题(软有机土壤的稳定)正在通过一种新的方法解决，这种材料(HCFA)目前是被填埋的。这个概念也是高风险的，因为已经开发了一个非常有限的数据集，表明HCFA确实是软有机土壤的有效稳定剂。然而，潜在的回报是可观的。这项研究的成功结果可以使HCFAs成为稳定软有机土壤(这是一个迄今尚未解决的问题)的首选材料，促进可持续发展和可持续的建筑实践，降低建设成本，并通过减少填埋的飞灰数量来改善环境。试验假设如下：(1)HCFAs可以有效地稳定软有机土壤；(Ii)HCFAs中的有机碳是成功稳定有机土壤的主要因素。为了验证这些假设，本文提出了一个由四项任务组成的研究计划。这些任务包括三种软有机土壤和三种六氯甲烷的物理和化学特征，它们代表了广泛的有机质(土壤)和有机碳(飞灰)含量，有机土壤和六氯甲烷混合物的无侧限压缩试验，评估这些混合物中胶结作用的微观结构分析，以及评估固化速度以间接评估有机质含量和有机碳含量如何影响胶结动力学。

Cementitious Class C fly ashes, as well as other cementing agents, have been found to be very effective stabilizers for soft inorganic soils, but are essentially ineffective at stabilizing soft organic soils. However, preliminary test data developed by the PIs has shown that soft organic soils can be effectively stabilized with cementitious high-carbon fly ashes (HCFAs), i.e., fly ashes with organic carbon content 3%. The objective of this SGER is to explore the feasibility of using HCFAs for stabilizing soft organic soils. This concept is novel because a long-standing unsolved problem (stabilization of soft organic soil) is being solved by a new approach with a material (HCFA) that is currently landfilled. The concept is also high risk, because a very limited data set has been developed showing that HCFAs are indeed effective stabilizers for soft organic soils. However, the potential rewards are substantial. Successful results from this study could make HCFAs the material of choice for stabilizing soft organic soils (a problem heretofore unresolved), foster sustainable development and sustainable construction practices, reduce construction costs, and improve the environment by reducing the volume of fly ash being landfilled. The hypotheses to be tested are as follows: (i) soft organic soils can be effectively stabilized with HCFAs and (ii) the organic carbon in HCFAs is the primary factor responsible for successful stabilization of organic soils with HCFAs. A research program consisting of four tasks is proposed to test these hypotheses. The tasks include physical and chemical characterization of three soft organic soils and three HCFAs that represent a broad range of organic matter (soil) and organic carbon (fly ash) contents, unconfined compression testing of mixtures of the organic soils and HCFAs, microstructural analyses to evaluate cementation in these mixtures, and an evaluation of curing rates to indirectly assess how the organic matter content and organic carbon content affect cementation kinetics.