I-Corps: Impact of extended time on fresh concrete and durability

点击翻译按钮获取中文摘要

The broader impact/commercial potential of this I-Corps project is the development of a type of concrete that reduces waste. More than one billion cubic yards of ready-mix concrete produced in the United States is returned to concrete plants every year. Much of this concrete is discarded as waste or washed out to reclaim the aggregates used in the system. This waste results in hardened concrete in landfills, contaminated washout water, and increased greenhouse gases. Reducing this may significantly improve sustainability by preventing unnecessary material in the landfill and reducing use of scarce water resources for washing, as well as improving operating costs. Furthermore, the main reason for truck rejections of concrete every year is due to the strict adherence to the 90-minute time limit. The technology is a concrete additive that allows mixed concrete to “sleep” to preserve the quality. This I-Corps project is based on the development of an improved concrete formula to allow extended mixing times without negatively impacting long-term durability. As traffic and road congestion has gotten progressively worse, this rule has unnecessarily increased construction cost and waste concrete. The proposed technology may extend mixing times by up to 150 minutes without negatively impacting the long-term durability of concrete mixtures. Recent studies examined hardened concrete properties such as compressive strength, freeze-thaw, and surface resistivity and indicate that the discharge time had no significant impact on the fresh properties, surface resistivity, and freeze-thaw durability up to 150 minutes. This technology may improve discharge time limits and extend specifications.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.