PCA R&D Serial No. 3007 Life Cycle Inventory of Portland Cement Concrete by by Medgar L. Marceau, Michael A. Nisbet, and Martha G. VanGeem ©Portland Cement Association 2007 All rights reserved KEYWORDS Concrete, energy, emission, life cycle inventory ABSTRACT A life cycle inventory (LCI) is a compilation of the energy and material inputs and the emissions to air, land, and water associated with the manufacture of a product, operation of a process, or provision of a service. This report is the second update of Environmental Life Cycle Inventory of Portland Cement Concrete, originally published in 2000 and updated in 2002. Similar to the original, this report presents the results of the LCI of three concrete products: ready mixed concrete, concrete masonry, and precast concrete. The system boundary, which defines the scope of the LCI, includes cement and slag cement manufacture; aggregate production; transportation of fuel, cement, supplementary cementitious materials, and aggregates to the concrete plant; and concrete plant operations (including truck mixer wash-out in the case of ready mixed concrete). Data on fuel and electricity use at concrete plants are from confidential life cycle inventory surveys of concrete plants conducted in 2006. The upstream profile of cement is imported from Life Cycle Inventory of Portland Cement Manufacture, which was also update in 2006. The previous edition presented fuel and electricity use and emissions to air (carbon dioxide, carbon monoxide, methane, nitrogen oxides, particulate matter, sulfur dioxide, and volatile organic compounds). This update presents emissions to land, over a dozen emissions to water, and dozens more emissions to air. Due to increases in energy efficiency, newer plants replacing older ones, and more accurate data (particularly for concrete plants and aggregate production), the present LCI results are lower for most of the flows reported in the previous edition. For example, for a typical 20-MPa (3,000-psi) concrete mix, embodied energy is 30% lower and CO2 emissions are about 7% lower. For concrete masonry, embodied energy is about 20% lower and CO2 emissions are about the same. For 50-MPa (7,500-psi) precast concrete, embodied energy and CO2 are unchanged because the LCI now includes energy and emissions at the precast concrete plant. REFERENCE Marceau, Medgar L., Nisbet, Michael A., and VanGeem, Martha G. Life Cycle Inventory of Portland Cement Concrete, SN3011, Portland Cement Association, Skokie, Illinois, PCA, 2007, 121 pages. i TABLE OF CONTENTS Keywords ......................................................................................................................................... i Abstract............................................................................................................................................ i Reference ......................................................................................................................................... i List of Tables ................................................................................................................................. iv List of Figures................................................................................................................................ iv Definitions........................................................................................................................................v Acronyms and Abbreviations ........................................................................................................ vi Introduction......................................................................................................................................1 Life Cycle Inventory................................................................................................................... 1 Intended Use of LCI Data........................................................................................................... 1 Definition of Goal and Scope ..........................................................................................................2 Goal............................................................................................................................................. 2 Scope........................................................................................................................................... 2 Product Function................................................................................................................. 2 Functional Unit. .................................................................................................................. 3 System Boundary................................................................................................................ 3 Data Sources ............................................................................................................................... 4 Fuel and Electricity............................................................................................................. 4 Raw Materials. .................................................................................................................... 4 Transportation..................................................................................................................... 4 Emissions. ........................................................................................................................... 4 Calculation Methodology ........................................................................................................... 5 Upstream Profiles.............................................................................................................................5 Transportation............................................................................................................................. 5 Quarry Haul-Road Emissions. ............................................................................................ 5 Cement........................................................................................................................................ 7 Supplementary cementitious materials ....................................................................................... 8 Aggregates .................................................................................................................................. 8 Ancillary Materials: Admixtures .............................................................................................. 11 Ready Mixed Concrete ..................................................................................................................11 Ready Mix Plant Operations..................................................................................................... 11 Energy............................................................................................................................... 12 Water................................................................................................................................. 13 Solid Waste............................................................................................................................... 13 Representative Mixes................................................................................................................ 13 Ready Mixed Concrete LCI Results ......................................................................................... 15 Ready Mixed Concrete LCI Analysis....................................................................................... 15 Energy............................................................................................................................... 15 Emissions. ......................................................................................................................... 16 ii Sensitivity Analyses.................................................................................................................. 16 Energy............................................................................................................................... 16 Combustion gases. ............................................................................................................ 16 Total Particulate Matter Emissions................................................................................... 17 Concrete Masonry Units ................................................................................................................22 Concrete Masonry Plant Operations......................................................................................... 22 Energy............................................................................................................................... 22 Water................................................................................................................................. 23 Solid Waste. ...................................................................................................................... 23 Representative Mixes................................................................................................................ 23 Concrete Masonry LCI Results................................................................................................. 24 Concrete Masonry LCI Analysis .............................................................................................. 24 Energy..............................................................................................................................