LCA of a prefabricated concrete shed produced by a sicilian firm

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1 LCA of a prefabricated concrete shed produced by a sicilian firm G.Siracusa 1, A.D.La Rosa 1, C.Ingrao 1, P.Neri 2 1 Department of Physical and Chemical Methodology for Engineering, University of Catania (Italy) 2 ENEA (National Agency for New Techincs, Energy and Environment) Ezio Clementel, Bologna (Italy). Address of presenting author: alarosa@dmfci.unict.it Keywords: concrete precast, life cycle assessment, environmental sustainability, industrial building ABSTRACT The aim of the present work is to characterize and analyze the main environmental impacts related to the life cycle of a prefabricated industrial shed made of reinforced concrete and produced by the Sicep s.p.a., a joint-stock company located in Catania (Italy). The study was developed using the Life Cycle Assessment methodology and the Simapro 7.0 software. The production process consists of several steps including mixing of raw materials (cement, inert, water and additives) in the concrete mixing plant and transferring, by means of small trucks, to the production lines in order to produce several types of precasts. The first stage of the LCA, was to define the system boundaries. Then, the functional unit was chosen, assuming as functional unit a medium industrial shed, (a shed with a plant surface of about 1720 m2 which is the main size produced by the company) with a temporal horizon of life of approximately years. It is opportune to specify that the choice of considering the shed as functional unit was thought of great interest for the evaluation of the environmental impacts generated by the productive activity. This work was developed distinguishing the concrete production process from the shed production process considering that the first is about producing the concrete in the concrete mixing plant, while the second concerns the fabrication of the precasts (beams, pillars, panels, Ondal tiles), composing the shed, beginning from the concrete produced. For the concrete production the functional unit of 1 m 3 of concrete was chosen. This process, once implemented in the program, was recalled in the shed production, considering that the amount of concrete necessary for the shed was 377 m3. In order to give a better rank of details to the study we choose to develop both the analysis of the concrete production and the shed production. Methodology The objective of the LCA study is the calculation of the environmental burdens related to the whole production chain of the Sicep [1] prefabricated industrial shed, the use phase and the end life, in a life cycle perspective. Data used for the study refers to the entire production in year 2005 and can be representative for 1 year, and they are specific data. The functional unit is a prefabricated industrial shed, (a shed with a plant surface of about 1720 m2 which is the main size produced by the company). A complete description of the phases of the LCA study is diagrammed in scheme 1. System boundaries The system under study is split into three phases as following : 1

2 Manufacturing phase Use phase: End life: Shed description 1. External extraction, processing and raw materials supply (external suppliers): - cement is mostly bought from Sicilian firms. ; - marble particles are partly from Sicily and partly from northern Italy; - basalt crushed and basalt milled are from quarries on the Etna (25 km); - Silica sand from a sicilian quarry (35 km) - calcareous powder is supplied from sicilian quarry (300 km). - steel is partly from Sicily and partly from Europe; 2. Processing of raw materials, production of a prefabricated industrial shed (Sicep, Catania); - the production mainly involves electric conveyors and machineries and fuel for the concrete mixing plant. - product delivery (by truck) mainly in Sicily and in south Italy - use of the shed as a shopping centre ( the energy consumption during the whole life time of the shed considering that the inside temperature should be between 20 C during and 26 C during summers was calculated by using the Termotecnica software [2]). - The end life concerns the choice of waste treatment for the materials, after the shed demolition. It was supposed the recycling as secondary filler in concrete manufactures. The thermal analysis results of the shed evaluated with the termotecnica software, are listed below: county: Catania; climate area: D; above sea level: 551 [m]; outside winter temperature: 5 [ C]; Average temperature: 11,8 [ C]; il FEP lim S/V= 0,2 [m -1 ]: 25,62 [kwh/m 2 ]; il FEP lim S/V= 0,9 [m -1 ]: 86,04 [kwh/m 2 ]; Heating time: 166 gg; Inside winter humidity: 65%; Outside winter hmidity: 75%; Inside summer humidity: 70%; Outside summer humidity: 80%; Thermal gradient: 11 [ C]; Outside temperature: 30 [ C]. Size of the shed: 7.80m high; long; 22 m deep; total surface 1728 m 2 ; Inside volume m 3. EPD system The present LCA study can be used by the company as a tool to obtain an environmental product declaration. The system for environmental product declarations the so-called EPD system is an attempt to apply ISO TR (a normative technical report for provisional use in the field of Type III environmental declarations) in practice. The system is based on Life Cycle Assessments, LCA, according to ISO The use of LCA has expanded among companies and organisations around the world and is more commonly regarded a strategic tool for a rational and preventive environmental work in general. LCA could be used for many purposes [3], e.g.: in product development work to identify opportunities to improve the environmental performance of products and services at various points in their life cycle in environmental management work as a base for a methodological approach in identifying significant environmental aspects and thereby to help in setting targets and objectives within the framework of an environmental management system 2

3 in communication and marketing giving a holistic basis for describing the environmental performance of products and services. Results and discussion Results from the LCA study show that the highest impacting phase is the use phase during summers as reported in table 2. For this reason two solutions were thought in the production phase of the shed in order to improve the environmental performance of the use phase: - To use an improved insulating system made of a thicker insulating layer consisting of a new material with a low thermal conductivity. - To use photovoltaic panels for electricity production. LCA results of the two proposed solutions are reported in figure 2. The use of photovoltaic panels, by producing electricity from a renewable source, improves the LCA of the shed: the damage category Resources, according to the Eco-indicator99, is reduced from 1.26E5Pt to 2.8E4 Pt; this is because the most impacting category, Fossil fuels, is reduced from 1.15E5 Pt a 2.46E4 Pt. References [1] Sicep s.p.a [2] Master thesis, Ecodesign per il recupero sostenibile di edifici in crudo. LCA di un unità abitativa reversibile in aree sensibili, PROT-P , ENEA, Bologna. [3] MSR 1999:2 Requirements for Environmental Product Declarations, EPD, The Swedish Environmental Management Council, , Stockholm, Sweden. 3

4 Scheme 1: work plan diagram Raw materials, resources and energy process of concrete Approach to the case study Defining the stages of the LCA of the shed process of the shed Use of the shed Shed End of life Analysis and evaluation Con Temotecnica Construction of the technological packages of the perimetral surface and the roof; calculation of the thermal power dispersed by the shed during Analysis and evaluation Plan of the thermal system and calculation of the primary energy of the shed Transferring data into SimaPro 70 Comparison between two types of basalt extraction from mine Comparison between 2 types of technological packages Insertion into the LCA Final Analysis Sensitivity Analysis Conclusions Improvement solutions Improving the insulation system of the shed surfaces Using photovoltaic panels 4

5 Figure 1and table1. LCA evaluation using Impact The main impact categories are shown in diagram. The amount of pollutants for each categories is reported in the table below. Table1 Potential environmental impacts Impact Unit Total Categories Amount Global Warming kgco 2 3,51E6 Non-renewable MJ primary 3,25E7 energy Respiratory kg PM2.5 2,19E3 Inorganics Noncarcinogens kg C 2 H 3 Cl 8,24E4 Terrestrial TEG soil 3,66E7 Ecotoxicity Acquatic TEG water 2,09E9 Ecotoxicity Carcinogens kg C 2 H 3 Cl 1,98E4 LCA phases Shed Use during Use during Shed End of summers Life 2,67E5 8,52E5 2,39E E6 7,59E6 2,2E7-5,58E ,38E3 0,669 4,5E4 1,04E4 2,71E4-59,1 4,72E6 8,83E6 2,3E7 1,32E4 3,7E7 5,23E8 1,53E9 1,04E5 9,71E3 2,86E3 7,31E3-66,1 5

6 Table 2. Environmental impacts for different LCA phases. Comparison between three different impact evaluation methods: Ecoindicator99, Impact 2002+, EPS Ecoindicator99 Impact EPS 2000 Total Damage (Pt) 1,93E5 Total Damage (Pt) 813 Total Damage (Pt) 2,75E6 Damage Human 29,6 % Damage Human 29,8 % Damage Human 20,2 % Categories Health Categories Health Categories Health Ecosystem Quality 4,93 % Ecosystem Quality 3,5 % Ecosystem 46,4 % LCA phases Resources 65,5 % Climate Change Use during summers Use during Shed Process Shed end life (avoided damage) Capacity 41,4 % Abiotic Stock Resources 33,2 % Resources 25,3 % Biodiversity 0,206% 65,6 % LCA Use during 65,5 % LCA Use during 70,7 % phases summers phases summers 22,6 % Use during 22,7 % Use during 24,4 % 14,1 % Shed 13,8 % Shed 8,17 % Process Process 2,29 % Shed end life (avoided damage) 1,99 % Shed end life (avoided damage) 3,28 % Figure 2. Comparison of the three analyzed systems: on the left the single score of the average industrial shed; in the middle the single score of the shed with photovoltaic panels and on the right the single score of the highly insulated shed. 6