To quantify and analyze environmental impacts of the processes within the defined system boundary, different types of environmental metrics are estimated in the form of inputs of resources (in the form of cement and concrete materials), and primary energy use (in the form of fuel and electricity), as well as environmental outputs of air emissions associated with the use of these resources, energy sources, and transportation of these resources.
The resource use input for concrete production encompasses a spectrum of extracted raw materials including limestone, gypsum, sand and gravel (as fine aggregates), crushed stone (as coarse aggregate), natural pozzolans; products of cement (traditional and blended types as defined by Standards (ASTM 2011; ASTM 2012), admixtures; and industrial by-products including fly ash and GBFS. Quantities of these raw materials and products are estimated in the life-cycle inventory of concrete. Nonetheless, the resource use associated with admixtures production is not provided in the tool as the available LCI data source ([EFCA] 2006) lacks the details about the quantities and sources of active ingredients in chemical admixtures. The volume of water consumed during the production processes of concrete and its major materials is also tabulated in the tool.
Primary energy used (in the form of fuel and electricity) throughout the production and transportation processes is one of the main environmental impacts analyzed as part of the study. Within the web tool, air emissions released from major processes (fuel pre-combustion, fuel combustion, electricity generation, transportation, and process-specific, e.g. calcination) that take place within the defined system boundary are:
The excel version has a more exhaustive list including:
Solid waste from pre-combustion and fuel combustion and electricity generation, and also from raw materials quarrying and production processes are also estimated in the Excel version, but not in the Web tool. Additionally, the Excel version of the tool conducts a life-cycle impact assessment based on TRACI Impact Category Weighting Factors for twelve environmental impact indicators.
The results from the GreenConcrete LCA tool are presented in graphical and tabular format. After running the analysis, the tool demonstrates primary energy use (in the form of fuel and electricity separately), water consumption, and GWP results in graphical format by life-cycle stages of concrete production starting with the extraction of raw materials to batching in the concrete plant ready for transportation to construction site.
The output can later be fed as an input to an overall environmental LCA of concrete buildings, and other structures, since the tool has the flexibility to allow users enter as many variations of concrete mix designs as possible that can be applied in different construction projects in different geographical locations with differing production technologies as well as electricity generation and transportation options both in the US and worldwide.
_____________________________________________________________________________________________________________________________________
For further information contact Petek Gursel at pgursel[at]berkeley.edu
HTML and Javascript Coding by Claudine Custodio