I-Corps: Next Generation Polymeric Stabilizer: Stabilization of Soil with High Shrink/Swell Potential

这个I-Corps项目的更广泛的影响/商业潜力将在土木工程基础设施发展项目中发现，这些项目是在受膨胀土壤影响的地区进行的，即土壤会因土壤湿度的变化而收缩和膨胀。这种地基土的收缩/膨胀活动是造成道路和其他基础设施系统结构损坏的主要原因。在美国，德克萨斯州、科罗拉多州、路易斯安那州、阿肯色州、密西西比州、阿拉巴马州、内布拉斯加州、北达科他州和南达科他州是由于膨胀土存在的主要问题。据报道，膨胀土壤在世界其他地区也造成了问题。传统上，石灰和波特兰水泥被用来稳定这种膨胀土。然而，这些传统的稳定剂不能在所有的土壤条件下使用。在这种情况下，唯一可行的解决方案是去除原生土壤，并用质量更好的材料代替。提出的I-Corps技术涉及一种可持续的土壤稳定剂，克服了传统稳定剂的许多局限性。它为目前使用移除和替换策略的项目提供了更经济的替代方案。这个I-Corps项目探索了一种新型土壤稳定剂的商业化机会，这种稳定剂使用一种被称为地聚合物的无机化合物作为关键成分。地聚合物是利用丰富的天然材料和/或工业副产品如粉煤灰和磨碎的高炉炉渣合成的。与传统的土壤稳定剂（即水合石灰和波特兰水泥）在生产过程中需要大量能源不同，地聚合物是在环境温度下或接近环境温度下合成的。因此，新的稳定剂代表了传统土壤稳定剂的更可持续的替代品。在产品开发阶段进行的大量实验室测试和微观结构研究表明，新型稳定剂可以减少90%以上的收缩/膨胀潜力。实验数据还证实，基于地聚合物的稳定剂可以有效地克服传统稳定剂存在的一些重大局限性，例如无法处理含硫酸盐土壤。传统的石灰稳定需要4-7天的等待时间才能发生稳定反应；这会导致工作流程的中断和施工的延迟。在这种情况下，新型稳定剂可用于处理原生土并改善其工程特性，从而无需进行昂贵的移除和替换操作。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this I-Corps project will be found in civil engineering infrastructure development projects where construction is undertaken in areas affected by expansive soils, i.e. soils that shrink and swell in response to changes soil moisture level. Such shrink/swell activity in foundation soils is a leading cause of structural damage to roadways and other infrastructure systems built upon them. In the United States Texas, Colorado, Louisiana, Arkansas, Mississippi, Alabama, Nebraska, North Dakota and South Dakota are among the states with major problems due to presence of expansive soil. Expansive soils have reportedly caused problems in other parts of the world as well. Traditionally, lime and Portland cement have been used to stabilize such expansive soils. However, these traditional stabilizers cannot be used in all soil conditions. In such situations, the only viable solution is to remove the native soil and replace it with better quality materials. The proposed I-Corps technology involves a sustainable soil stabilizer that overcomes many of the limitations found in the traditional stabilizers. It provides a more economical alternative in projects where remove-and-replace strategy is currently used. This I-Corps project explores opportunities for commercialization of a novel soil stabilizer which uses an inorganic compound known as geopolymer as the key ingredient. Geopolymers are synthesized using abundantly available natural materials and/or industrial by-products such as fly ash and ground blast furnace slag. Unlike traditional soil stabilizers (viz. hydrated lime and Portland cement) which require vast amounts of energy during production, geopolymers are synthesized at or near ambient temperatures. Accordingly, the new stabilizer represents a more sustainable alternative to traditional soil stabilizers. Extensive laboratory testing and microstructural studies conducted during the product development phase demonstrate that the new stabilizer can achieve more than 90% reduction in shrink/swell potential. The experimental data also confirm that the geopolymer-based stabilizer can be used effectively to overcome a number of significant limitations that exist in the traditional stabilizers, such as inability to treat sulfate-bearing soils. Traditional lime stabilization requires a waiting period of 4-7 days for the stabilizing reactions to take place; this causes interruption in work flow and delay in construction. In such situations, the new stabilizer can be used to treat the native soil and improve its engineering properties and thus eliminate need for expensive remove-and-replace operations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.