Dynamic Modeling of Cement In-Use Stocks in United States
The key attributes of sustainable infrastructure systems are – extended service life, enhanced performance, optimal life cycle costs, and minimal environmental life cycle impacts including the use of virgin raw materials. The rate of addition of new stock and the repair of existing stock are key determinants of infrastructure sustainability. The condition and performance of, especially, concrete infrastructure, in the United States has shown an alarming decline and it is anticipated that billions of dollars of investment will be required over the next decade to replace and/or rehabilitate existing structures. Globally, contemporary concrete production is approximately 12 –15 billion metric tons Cement is an essential component of concrete, usually in the range of 10- 15% by volume. The production and use of cement are both energy- and material- resource intensive. The objective of this study is to characterize the stocks and flows of cement mobilized and utilized during the twentieth century in United States using the generic cement life cycle. The motivation for estimating historical inventories of cement stocks and flows is to provide accurate informed estimates of contemporary cement in-use stocks in U.S.