SBIR Phase I: Sustainable Engineering of Lightweight Aggregate for Concrete Use from Waste Coal Combustion Ash

SBIR一期项目的广泛影响有两方面：(1)增加混凝土行业建筑轻骨料（LWA）的可及性；(2)将废煤燃烧灰（W-CCA）转化为增值产品（即建筑轻骨料）。美国每年产生约1亿吨燃煤灰，其中只有约60%被回收利用，其余都被送往垃圾填埋场。这给人类健康和环境带来了风险。与此同时，在一些州，由于缺乏当地的建筑LWA制造商，传统上由粘土、板岩和页岩生产的建筑LWA的可及性对混凝土行业来说是一个挑战。因此，LWA必须从国内其他地方进口，增加了(i)材料的最终成本和（ii）运输造成的温室气体排放。随着大量的W-CCA垃圾填埋场分散在美国各地，LWA可以从垃圾填埋场附近的这种材料生产，以增加混凝土行业建筑LWA的当地可达性。通过实施该技术，W-CCA将减少对环境的影响，防止自然资源的消耗，减少与材料运输相关的二氧化碳排放，并且用户可以通过获得当地的建筑LWA来节省资金。这个小企业创新研究（SBIR）第一阶段项目解决了从废煤燃烧灰（W-CCA）中生产新型多孔轻骨料（LWA）的相关障碍。W-CCA的熔融特性使生产具有优越工程性能的建筑LWA，包括相对于传统LWA增加的吸水/解吸能力和混凝土和易性。本项目可交付成果包括：(i)在中试规模生产期间开发具有理想烧结性能的LWA，以确保扩大所建议技术的技术可行性；（ii）优化中试规模回转窑参数，以转化为大规模生产；（iii）在实验室中试规模生产的混凝土应用中展示LWA的优越工程性能；（iv）在封装混凝土应用中展示基于W-CCA的LWA的不可浸出性。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 of this SBIR Phase I project is two-folds: (1) increasing the accessibility of construction lightweight aggregate (LWA) for the concrete industry and (2) conversion of waste coal combustion ash (W-CCA) to value-added products (i.e., construction LWA). Yearly, about 100 million tons of coal combustion ash is produced in the US, of which only about 60% is recycled and the rest is moved to the landfills. This imposes risks to human health and the environment. Meanwhile, accessibility of construction LWA that is traditionally produced from clay, slate, and shale is challenging for the concrete industry in some states due to the absence of local construction LWA manufacturers. Therefore, LWA must be imported from elsewhere in the country, increasing (i) the final cost for the material and (ii) greenhouse gas emission due to transportation. With an abundance of W-CCA landfills scattered throughout the US, LWA can be produced from this material near the landfill sites to increase the local accessibility of construction LWA for the concrete industry. By implementing this technology, the environmental impact of W-CCA will be reduced, natural resource consumption will be prevented, CO2 emission associated with material transportation will be reduced, and users can save money by having access to local construction LWA.This Small Business Innovation Research (SBIR) Phase I project addresses hurdles associated with manufacturing a novel porous lightweight aggregate (LWA) produced from waste coal combustion ash (W-CCA). The melting properties of W-CCA enable the production of construction LWA with superior engineering properties, including increased water absorption/desorption capacity and concrete workability relative to traditional LWA. The deliverables of this project include: (i) development of a LWA with desired sintering properties during pilot-scale production to assure technical feasibility of scaling-up the proposed technology, (ii) optimization of pilot-scale rotary kiln parameters translatable to large-scale production, (iii) demonstration of the superior engineering properties of LWA for concrete applications produced at lab pilot-scale, and (iv) demonstration of the non-leachability of W-CCA based LWA in encapsulated concrete applications.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.