Dynamic Material Flow Analysis of Cement in Iran: New Insights for Sustainability of Civil Infrastructures

Abstract

In this article, a Dynamic Material Flow Analysis (DMFA) model is presented that characterizes the stocks and flows of cement from 1963 to 2063 in Iran. Using cement consumption data for the period of 1963-2018 an attempt is made to provide reliable estimates of the present as well as future cement in-use stocks and discards (from 2019 to 2063) to relevant stakeholders such as the Ministry of Road and Urban Development, Department of Environment, public and private utilities, and the construction and cement industries. Based on a normal lifetime distribution, a flow dynamic model is developed for each cement end-use category including buildings, infrastructures and others. Each sub model is simulated with 9 scenarios made from combinations of 3 scenarios for future cement consumption growth rate and 3 scenarios for the mean lifetime of the structures. For the base scenario, the model-derived estimate of in-use cement stock and cumulative discard for the year 2063 is 2191 million metric tons (Mt) and 1856 Mt, respectively. Such a great discard should be considered in policy making for better life cycle management of cement in Iran. The main finding of the paper is that by increasing the mean lifetime of the structures (especially buildings), the amount of cumulative cement discard in 2063 can be drastically decreased (generally over 50%) and this decrease will not be affected considerably by the cement consumption growth rate in the future. So this can be a reliable strategy for the sustainable life cycle management of infrastructures in Iran.