(211c) Novel Application of Waste Concrete to Clean up the Air and Improve the Reliability of Civil Infrastructure | AIChE

(211c) Novel Application of Waste Concrete to Clean up the Air and Improve the Reliability of Civil Infrastructure

Authors 

Orlov, A. - Presenter, Stony Brook University
Patel, S., Stony Brook University
Ariyachandra, E., Clarkson University
Peethamparan, S., Clarkson University
Concrete is by far the most abundant material produced by humanity in both by volume and weight. High temperatures and oxidizing atmosphere in cement kiln generate NO2 which is one of the criteria air pollutants. Removing NO2 from cement kilns can have tremendously beneficial effects on the environment and human health. Sequestering NOx in demolished concrete is an innovative, cost-effective, and sustainable approach to remove NO2 flue-gas from cement and other industrial plants to minimize the environmental impact. Most importantly, the NOx sequestered demolished concrete (NSDC) can act as a corrosion inhibitor in new concrete. In this study, the NOx sequestration by the waste concrete at an elevated temperature similar to the temperature of the flue gas was investigated. The gas phase uptake experiments were performed on the concrete of different ages: such as 1, 2 and 20-year-old concrete. The mechanistic information of concrete samples before and after NO2 exposure at 250C, 1500C, and 2500C was obtained using time-resolved DRIFTs and gas phase analysis. Additional confirmation of reaction pathways was obtained using TGA results. In addition, the effectiveness of NSDC as a potential corrosion inhibitor was evaluated. In this study, the fine aggregate in a fresh OPC concrete was replaced with 40% of NSDC by volume. The resistance to chloride-induced corrosion was evaluated by the linear polarization resistance (LPR) technique. Electrochemical test results show that NSDC can mitigate corrosion of steel in concrete, providing similar protection level compared to commercially available corrosion inhibitors.