University Transportation Research Center
concrete, Crushed aggregates, Demolition, Environmental impacts, Infrastructure, Nitrogen dioxide, Sustainable development, Volatile organic compounds, Wastes
Achieving environmental sustainability of the United States (US) transportation infrastructure via more environmentally sound construction is not a trivial task. This proposal, which addresses this critical area (Focus Area 3), is aiming at transforming concrete, the material of choice for many transportation projects, into less environmentally harmful and better performing component of the US infrastructure. This will be extremely relevant to construction of pavements, bridges, tunnels, airports, marine installations and other transportation projects. Simultaneously, the project will address one of the most pressing public health issues, such as NO? emissions from cement kilns, by developing new applications of crushed concrete aggregates (CCA), which are already contributing to resource conservation and elimination of solid waste disposal issues. NO? emissions can cause various environmental and health problems. They contribute to the formation of acid rain, atmospheric particles, and various other toxic substances resulting in health problems, visibility reduction, eutrification and global warming. One of the most prevalent problems with NO? emissions is the formation of ground level ozone, which is produced by NO? (NO+NO?) reacting with volatile organic compounds (VOCs) and CO in the presences of sunlight. Ground level ozone can damage lung tissue and reduce lung function. It is a significant problem nationwide as millions of Americans live in areas that do not meet the health standards for ozone. Among many sources of NO? emissions cement kilns are very significant contributors. They emit over 219,000 tons/year of NO?, which amounts to approximately 20% of all industrial emissions. High temperatures reached in cement kilns are favorable for NO? emissions and cannot be avoided.