PFI-TT: Eco-friendly concrete for cheaper and safer concrete pipes

这项创新技术转化伙伴关系（PFI-TT）项目具有更广泛的影响和商业潜力，它是一种专利混凝土，可以用再生钢纤维和再生沥青路面的骨料取代传统的钢筋。通过对精选回收材料的精心设计，该专利混凝土将降低混凝土管道成本高达40%，二氧化碳排放量高达19%，同时保持卓越的强度和韧性。该项目侧重于优化用于制造混凝土管道的特殊混凝土设计，并在一家商业管道制造商进行全尺寸原型测试。将对特殊混凝土管道进行生命周期评估，以量化整个德克萨斯州和美国的经济和环境效益。通过使用这种特殊的混凝土，美国管道工业每年可以节省超过738,000吨的钢和超过2,700,000吨的原始骨料。仅回收钢纤维的使用就可以减少136万吨二氧化碳排放到大气中，相当于每年减少52.1万辆行驶1.5万公里的汽车。拟议中的项目将通过消除手工加固来缓解成本高昂的劳动力短缺，并满足预制混凝土行业对低碳足迹建筑材料的需求——由最近和即将出台的立法推动。该项目的目标是设计和验证特殊的专利混凝土管，减少或没有预埋钢笼，可以取代市场上现有的传统增强管。研究方法包括实验室测试，以开发再生钢纤维和再生沥青路面的关键性能（如尺寸、形状、长径比、涂层厚度、杂质质量分数和性能可变性）与特殊混凝土的关键材料性能和全尺寸管道的结构性能之间的新功能关系，包括拉伸强度、弯曲强度、断裂性能、稳定性、以及管道故障载荷。全尺寸原型测试将验证特殊混凝土取代传统钢筋混凝土用于管道应用的能力，而生命周期评估将量化使用特殊混凝土用于管道的环境和经济效益。研究结果将对干浇筑过程中钢纤维增强混凝土的性能以及再生沥青路面骨料对干浇筑可加工性、稳定性和固结性的影响产生新的认识。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 Partnerships for Innovation – Technology Translation (PFI-TT) project is a patented concrete that has been developed to replace conventional reinforcing steel with recycled steel fibers and aggregates from recycled asphalt pavement. Through this engineered use of select recycled materials, the patented concrete will reduce concrete pipe costs by up to 40% and carbon dioxide release by up to 19%, while retaining superior strength and toughness. This project focuses on optimizing the special concrete design used to manufacture concrete pipes and full-scale prototype testing at a commercial pipe manufacturer. A life-cycle assessment will be conducted for the special concrete pipes to quantify the economic and environmental benefits throughout Texas and the US. By using this special concrete, the US pipe industry could annually save over 738,000 tons of manufactured steel and over 2,700,000 tons of virgin aggregates. The use of the recycled steel fiber alone would save 1.36M tons of carbon dioxide from being released into the atmosphere – equivalent to removing 521,000 cars traveling 15,000 km per year from the roads. The proposed project will relieve costly workforce shortages by eliminating hand-tying of reinforcement and satisfy the need in the precast concrete industry – driven by recent and impending legislation – for lower carbon footprint construction materials. The goal of this project is to design and validate the special, patented concrete pipes with reduced or no embedded steel cages that can replace existing conventional reinforced pipes in the market. The research approach involves lab testing to develop new functional relationships between key properties of recycled steel fiber and recycled asphalt pavement (e.g., sizes, shapes, aspect ratios, thickness of coating, mass fraction of impurities, and property variabilities) and key material performance properties of the special concrete and structural performance properties of full-scale pipes, including tensile strength, flexural strength, fracture properties, stability, and pipe failure loads. Full scale prototype testing will validate the capability of the special concrete to replace conventional reinforced concrete for pipe applications while the life-cycle assessment will quantify the environmental and monetary benefits of using the special concrete for pipes. The results will yield new understanding of steel fiber-reinforced concrete behavior in the dry-cast manufacturing process and the impact of recycled asphalt pavement aggregates on dry-cast workability, stability, and consolidation.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.