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开发项目中找到，这些项目在受膨胀土影响的地区进行施工，即随着土壤湿度的变化而收缩和膨胀的土壤。地基土中的这种收缩/膨胀活动是对道路和建立在其上的其他基础设施系统造成结构性破坏的主要原因。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都是由于膨胀的土壤而存在严重问题的州。据报道，膨胀土在世界其他地区也造成了问题。传统上，石灰和波特兰水泥是用来稳定这种膨胀土的。然而，这些传统的稳定剂并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移走原生土壤，用质量更好的材料取而代之。拟议的i-Corps技术涉及一种可持续的土壤稳定器，它克服了传统稳定器中的许多限制。在当前使用拆卸和更换策略的项目中，它提供了一种更经济的选择。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。利用大量可用的天然材料和/或工业副产品，如飞灰和磨碎的高炉矿渣，合成地聚合物。不同于传统的土壤稳定剂(即由于消石灰和硅酸盐水泥)在生产过程中需要大量能源，因此地聚合物是在环境温度或接近环境温度下合成的。因此，新型稳定剂代表着传统土壤稳定剂的一种更可持续的替代品。在产品开发阶段进行的广泛实验室测试和微观结构研究表明，新型稳定剂可以将收缩/膨胀潜力降低90%以上。实验数据还证实，基于土聚合物的稳定剂可以有效地克服传统稳定剂中存在的一些显著限制，如无法处理含硫酸盐的土壤。传统的石灰稳定化需要4-7天的等待期才能发生稳定反应；这会导致工作流程中断和施工延误。在这种情况下，新的稳定剂可用于处理原生土壤并改善其工程性能，从而消除昂贵的拆卸和更换操作的需要。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.