I-Corps: High-performance cementitious material

I-Corps：高性能胶凝材料

• 批准号: 2136006
• 负责人: Xijun Shi
• 金额: $ 5万
• 依托单位: Texas State University - San Marcos
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2136006&HistoricalAwards=false
• 关键词: Corps; performance; cementitious; material

The broader impact/commercial potential of this I-Corps project involves the development of a novel concrete mixture containing recycled steel fiber (RSF) as fiber reinforcement, and reclaimed asphalt pavement (RAP) as a virgin aggregate replacement. Rebar reinforcement makes conventional reinforced concrete structures less economical due to the material cost of the steel and the labor cost to install the rebar. The presence of rebar also makes concrete placement difficult and may lead to settlement cracking. Concrete blended with randomly-oriented RSF provides a solution for more affordable and versatile concrete structures by eliminating rebar reinforcement. Additionally, both RSF and RAP are underutilized in concrete. The existing applications of these materials, typically viewed as waste, have major limitations: RSF has been conventionally sold as scrap steel to make new steel, which is less economical and has higher environmental impact than direct reuse. RAP has been primarily used in new asphalt pavement but that usage is often restricted due to pavement cracking problems. By using RSF and RAP in concrete, significantly less energy and raw materials are consumed compared to to conventional concrete.This I-Corps project is based on the development of a cost-effective, high-performance, sustainable concrete. Unlike conventional concrete that is often brittle and rigid, this new concrete is semi-rigid. The new system uses recycled steel fiber (RSF) as fiber reinforcement, which markedly increases concrete toughness and ductility due to the fibers' ability to bridge cracks. Reclaimed asphalt pavement (RAP) is added as intermediate-sized coarse aggregate to achieve optimized aggregate gradation. Aggregate gradation optimization reduces paste content in concrete and this, in turn, results in better concrete performance and reduced shrinkage. Additionally, replacing virgin aggregate with RAP also produces more ductile and crack resistant concrete because of the viscoelastic nature of the asphalt in RAP that leads to high stress relaxation. The asphalt coating on RAP acts as a lubricant and increases the flowability and pumpability of the materials. Finally, the new concrete has better damping properties, which may more effectively reduce noise and vibration damage caused by wind and earthquakes.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.

这个i-Corps项目的更广泛的影响/商业潜力包括开发一种新型的混凝土混合物，其中含有再生钢纤维(RSF)作为纤维增强材料，再生沥青路面(RAP)作为原始骨料的替代品。由于钢筋的材料成本和安装钢筋的劳动力成本，钢筋加固使传统的钢筋混凝土结构变得不经济。钢筋的存在也使混凝土浇筑变得困难，并可能导致沉降裂缝。混凝土与随机取向的RSF混合，通过消除钢筋，为更实惠和更多功能的混凝土结构提供了一种解决方案。此外，RSF和RAP在混凝土中都没有得到充分利用。这些材料的现有应用通常被视为废物，具有重大局限性：传统上，RSF一直作为废钢出售以制造新钢，与直接再利用相比，这不太经济，对环境的影响更大。RAP主要用于新的沥青路面，但由于路面开裂问题，其使用往往受到限制。通过在混凝土中使用RSF和RAP，与传统混凝土相比，消耗的能源和原材料显著减少。这个i-Corps项目基于开发一种成本效益高、高性能、可持续的混凝土。与通常脆性和刚性的传统混凝土不同，这种新型混凝土是半刚性的。新系统使用再生钢纤维(RSF)作为纤维加固，由于纤维能够桥接裂缝，显著提高了混凝土的韧性和延性。采用再生沥青路面(RAP)作为中级配粗集料，达到优化集料级配的目的。骨料级配优化减少了混凝土中的浆体含量，进而导致更好的混凝土性能和减少收缩。此外，由于RAP中沥青的粘弹性导致高应力松弛，用RAP取代原始骨料还可以生产更具延展性和抗裂性的混凝土。RAP上的沥青涂层起到了润滑剂的作用，增加了材料的流动性和可泵性。最后，新混凝土具有更好的减震性能，可以更有效地减少风和地震造成的噪音和振动破坏。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。