PFI-TT: Bio-inspired enhancement of concrete for carbon sequestration and longevity

这一创新-技术转化伙伴关系(PFI-TT)项目的更广泛影响是开发新型生物灵感添加剂，这些添加剂将增强碳封存、机械性能和混凝土的寿命。普通波特兰水泥(OPC)是美国最耗能的制造业之一，占全球人为碳排放的近8%。由于OPC的高碳足迹，在过去的十年里开发了各种替代的低碳胶凝材料，其中许多依赖于二氧化碳(CO2)固化。然而，能够控制这种新一代CO2养护混凝土性能的潜在化学外加剂还没有得到很好的探索，这主要是因为对这些材料的硬化机理缺乏了解。该项目专注于设计和解决专门为二氧化碳养护混凝土配制的生物灵感外加剂的升级挑战。仿生外加剂将改善二氧化碳养护混凝土的功能，从而扩大此类低碳技术的应用领域。这些低碳技术的应用将使美国政府实现到2050年实现净零排放的目标。拟议的项目旨在通过以下四项任务升级和评估仿生外加剂的商业化潜力：(I)评估仿生外加剂与通常用于控制混凝土不同性能的传统化学外加剂的兼容性；(Ii)调查不同长度尺度和环境条件下不同二氧化碳浓度水平下仿生外加剂的有效性；(Iii)调查使用仿生外加剂制备的混凝土的耐久性能。以及(4)对在碳化养护水泥基复合材料生产中生产和使用仿生添加剂进行环境影响评估和技术经济评估。碳酸钙矿物(CaCO3)是控制碳化养护水泥基复合材料强度和固碳能力的主要结合相。发现一系列仿生添加剂能够控制碳化养护水泥基复合材料中CaCO3的析出和晶型转化动力学。这样，这些添加剂可以提高碳化养护水泥基复合材料的力学性能、二氧化碳封存能力和耐久性。为了降低这些仿生添加剂扩大规模和商业化的潜在风险，本项目将评估它们在不同胶凝材料系统、长度尺度和环境条件下的性能和成本效益。该奖项反映了NSF的法定使命，并通过使用基金会的智力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 of this Partnerships for Innovation - Technology Translation (PFI-TT) project is to develop novel bio-inspired additives that will enhance carbon sequestration, mechanical performance, and the longevity of concrete. Ordinary Portland Cement (OPC) is one of the most energy-intensive manufacturing industries in the U.S. and is responsible for nearly 8% of global anthropogenic carbon emissions. Due to the high carbon footprint of OPC, a variety of alternative low-carbon cementitious materials have been developed in the past decade, many of which rely on carbon dioxide (CO2) curing. However, the potential chemical admixtures, that can enable controlling the performances of this new generation of CO2-cured concrete have not been well-explored yet, primarily due to the lack of understanding of the hardening mechanism of these materials. This project focuses on designing and resolving the upscaling challenges of bio-inspired additives specifically formulated for CO2-cured concrete. The bio-inspired additives will improve the functionality of CO2-cured concrete and therefore, expand the application sector for such low-carbon technologies. The application of such low-carbon technologies will enable the U.S. government’s goal of reaching Net Zero emissions by 2050.The proposed project aims to upscale and evaluate the commercialization potential of bio-inspired additives via following four tasks: (i) evaluate the compatibility of bio-inspired additives with traditional chemical admixtures that are typically used to control different performances of concrete, (ii) investigate the effectiveness of bio-inspired additives at different length scales and environmental conditions with variable CO2 concentration levels, (iii) investigate the durability performances of concrete prepared using bio-inspired additives, and (iv) perform environmental impact assessment and techno-economic assessment of producing and using bio-inspired additives in the production of carbonation cured cementitious composites. Calcium carbonate (CaCO3) mineral is the primary binding phase that controls the strength as well as the CO2 sequestration capacity of carbonation-cured cementitious composites. A series of bio-inspired additives were found to be able to control the CaCO3 precipitation and polymorph conversion kinetics in carbonation-cured cementitious composites. By doing so, these additives can enhance the mechanical performance, CO2 sequestration capacity, and durability of carbonation-cured cementitious composites. To mitigate the potential risks of upscaling and commercialization of these bio-inspired additives, their performance and cost-effectiveness for different cementitious material systems, length scales, and environmental conditions will be evaluated in this project.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.