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

这个创新技术转化伙伴关系(PFI-TT)项目的更广泛的影响/商业潜力是一种专利混凝土，它已经被开发出来，用再生的钢纤维和再生沥青路面的骨料来取代传统的钢筋。通过精选回收材料的工程化使用，获得专利的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%，同时保持优异的强度和韧性。该项目的重点是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，美国管材行业每年可以节省超过73.8万吨的钢材和超过270万吨的原始骨料。仅使用回收的钢纤维就可以节省136万吨二氧化碳排放到大气中，相当于每年减少52.1万辆汽车行驶1.5万公里。拟议的项目将通过消除钢筋的手工捆绑来缓解昂贵的劳动力短缺，并满足预制混凝土行业对低碳足迹建筑材料的需求--受最近和即将出台的立法的推动。该项目的目标是设计和验证特殊的专利混凝土管道，减少或不嵌入钢笼，以取代市场上现有的常规钢筋管道。该研究方法涉及实验室测试，以建立再生钢纤维和再生沥青路面的主要性能(例如，尺寸、形状、长宽比、涂层厚度、杂质质量分数和性能变异性)与特殊混凝土的关键材料性能特性和足尺管道的结构性能特性之间的新的函数关系，包括抗拉强度、弯曲强度、断裂性能、稳定性和管道破坏载荷。全尺寸原型测试将验证特殊混凝土在管道应用中取代传统钢筋混凝土的能力，而生命周期评估将量化管道使用特殊混凝土的环境和经济利益。这一结果将使人们对钢纤维混凝土在干浇注制造过程中的行为以及再生沥青路面骨料对干浇注工作性、稳定性和固结的影响有新的理解。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 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.