Highly Ductile and Durable Double-network based Cementation - D3 Cement

该项目的目标是探索一种非传统的胶结技术，使用高韧性和耐用的双网络材料，即“D3水泥”。“这项研究主要解决了两个具有挑战性的问题-脆性和非耐久性-与目前的化学或生物胶结土壤。具体地说，许多矿物沉淀处理的土壤可能是坚硬的，但在低应变下容易破裂。水凝胶处理过的生物胶结土壤在干燥时更具延展性，但当暴露于水时失去其强度，因为吸水亲水聚合物网络的大体积膨胀破坏了土壤颗粒之间的结合。D3水泥在岩土工程、土木、环境和石油领域具有广泛的潜在应用，包括粉尘控制、基础设施建设和液化缓解，可能节省数百万美元的成本。 这项研究还将创建一个大型数据集，其中包含有关基本生物-无机-有机-土壤界面相互作用的新知识，以及与其力学性能（强度，刚度，延展性）的关系。 多元化的教育和外展活动将促进K-12和公共教育，并为PI材料实验室和合作者生物地理技术实验室的团队举办跨学科研究生工作坊。在这个跨学科项目中，本发明的目的是通过开发一种新的水泥来克服在低应变下断裂和不耐久的局限性，所述水泥1）具有延展性和刚性，2）对水较不敏感，通过将材料科学的概念独特地扩展到生物胶结，引起土壤强度损失。 其方法是设计开发一种混合胶凝材料，能够在土壤中同时形成有机与无机互穿的双重网络，并与土壤颗粒形成牢固的结合，通过有机-无机-土壤的可重组结合，具有新型的自愈能力。 将通过控制材料成分、形态和分层结构来检查新复合材料的性能。 这项研究如果成功，将产生一种高性能的生物基地质材料。这项工作将与美国国家科学基金会资助的亚利桑那州立大学生物介导和生物启发岩土工程中心的研究人员合作完成。

The goal of the project is to explore a non-conventional cementation technique using highly ductile and durable double-network materials, namely "D3 cement." This research mainly addresses two challenging issues - brittleness and non-durability - with current chemically or biologically cemented soil. Specifically, many mineral precipitation-treated soils can be stiff, but break easily at low strains. Hydrogel-treated bio-cemented soil has been found more ductile upon drying, but loses its strength when exposed to water, as the large volume expansion of the water-absorbing hydrophilic polymer network breaks the bonding between the soil particles. The D3 cement has broad potential applications in geotechnical, civil, environmental and petroleum fields, including dust control, infrastructure construction, and liquefaction mitigation, with potentially millions of dollars of cost savings. This research will also create a large data set rich in new knowledge on fundamental bio-inorganic-organic-soil interface interactions, and the relationship with their mechanical properties (strength, stiffness, ductility). Diverse education and outreach activities will promote K-12 and public education and Cross-disciplinary Graduate Workshop for the teams from the PI's Materials Lab and the collaborator's Biogeotech Lab.In this cross-disciplinary project, the objective is to overcome the limitations of fracture at low strains and non-durability by developing a novel cement that is 1) ductile and stiff and 2) less susceptible to water-induced soil strength loss, by uniquely extending concepts of material science to bio-cementation. The approach is to design and develop a hybrid cementing materials which can simultaneously form an organic-and-inorganic, interpenetrating double network in the soil and strongly bind the soil particles, possessing novel self-healing ability via organic-inorganic-soil reformable bonding. The performance of the new composite material will be examined with controls over the material composition, morphology, and hierarchical structures. This research, if successful, will yield a high-performance bio-based geological material. The work will be done in collaboration with researchers at the NSF-funded Center for Bio-mediated and Bio-inspired Geotechnics at Arizona State University.