Maria LUPSEA 1,2, Nicoleta SCHIOPU 1, Ligia TIRUTA-BARNA 2

Transcription

1 Leaching of construction products during their use stage: proposal for a reliable life cycle inventory (LCI) of the released substances in water and soil Maria LUPSEA 1,2, Nicoleta SCHIOPU 1, Ligia TIRUTA-BARNA 2 1 Université Paris-Est; CSTB France 2 Université de Toulouse; INSA; UPS; INP; LISBP, INRA;CNRS France Session: LCI data: validation, aggregation and uncertainties CONTACT : maria.lupsea@cstb.fr

2 Leaching data Leaching data characteristics Particularities obtained from lab, pilot or filed scale tests, in controlled or natural exposure conditions represent the concentration of substances in volume of leachate (demineralised water or rainwater) in mg/l or mol/l leaching tests in dynamic conditions emissions of substances per mass or surface of product, i.e. mg/kg or mg/m² leaching test in natural conditions emissions from construction products over a certain period (duration of rain) direct extrapolation form the leaching test data also possible, but rather incorrect (leaching tests operate at different time scales and physico-chemical conditions as the real leaching scenario) modelling and simulation of dynamic release possible specialised models and software (e.g. PHREEQC, CHEM-CHESS, PHAST, etc.) which couple chemical and transport mechanisms 2

3 Why coupling leaching with LCA data? 3

4 Why coupling leaching with LCA data? Air Indoor air Surface water Environmental Product Declarations (EPDs) Soil Groundwater Environmental impact Global warming Ozone depletion Product stage Construction process Total water consumption Usually, water emissions during use stage: Waste Either: generation under estimated (0 emissions) Climate Or: over change estimated (100% of Total Content) Air pollution Water pollution... Use stage End of life stage 4

5 Why coupling leaching with LCA data? Case study: cement based construction products Release during use stage (leaching data)* Release during use stage (EPDs data)** Release during whole lifecycle (EPDs data) Contribution of of release during use stage (leaching data) Unit mg/m²/year mg/m²/year mg/m²/year % Al Cr Cu Zn DOC * Schiopu, N., 'Caractérisation des emissions dans l eau des produits de construction pendant leur vie en oeuvre', ** Syndicat National du Béton Prêt à l Emploi (SNBPE), 'Déclaration environnementale et sanitaire conforme à la norme NF P : Dallage industriel à base de béton XF1 C25/30 CEM II',

6 Why coupling leaching with LCA data? Very low concentrations of hazardous species and other released substances?? insignificant?? cumulated mass of the substance leached per FU estimated on appropriate time spans 6

7 Approach Which product characteristics have to/can be used (initial composition, experimental data, etc.)? How to exploit leaching data? How to include the appropriate information in LCA evaluations? 1) identification of the emission scenario to be considered with LCA framework 2) including leaching data in LCA 7

8 Emission scenarios Exposure scenarios 1) Sloping plane (slope higher than 15%) pitched roof, generally roofing and covering products The main water contact type is the runoff 2) Horizontal plane products for terrace (concrete, pavement bricks, wood, metal slabs, etc.), products used in public works like road Rain water can either form stagnant layers, or runoff, or infiltrate and percolate the product if it is porous 3) Vertical façade type products exposed to rain water (bricks, concrete, wood, etc.) Rain waters runoff and in a certain degree infiltrate if the product is porous 4) Contact with soil foundations for all categories of civil works All contact types are possible: water runoff, stagnation, infiltration, percolation 5) Works completely immersed in water dikes, piles, basins, made generally of concrete based products, granulates, wood, etc. 8

9 Leachates from scenarios 1-5 Emission scenarios A. leachates going directly into the soil (beneath or surrounding the product) as in exposure scenarios 1 to 4 B. going directly into water bodies (groundwater, river, sea,..) as in exposure scenario 5 Soil Non-saturated zone Saturated zone Ground water flow 9

10 Including leaching data in LCI Methodology The proposed solution for the LCI calculation assess the emissions towards the identified target compartments, i.e. soil and water, for the chosen FU in line with the LCA methodology can have a general applicability and could feed also general data bases calculate the cumulated mass of each pollutant released from the FU over the life span of the construction product 10

11 Under estimation Expertise Over estimation Including leaching data in LCI Application case concrete paving slab ( cm 3 ), manufactured by using CEM I-based concrete the sample was submitted to various experiments (lab tests, field scale tests, modelling, etc.) RSL (reference service life) = 30 years FU = 1 m² of surface covered with 15 cm thick concrete slabs case illustrated only for the leaching of cooper and chlorides 1. Considering that the whole initial content of the product leaches during the use phase 8.71 g Cu ( 3600% of simulation over RSL) g Cl - ( 750% of simulation over RSL) 2. Considering the leaching data obtained by ANC tests (48h, aggressive, mg/kg) 3.48 g Cu ( 1400% of simulation over RSL) g Cl - ( 600% of simulation over RSL) 3. Using dynamic leaching data from laboratory DSLT tests (64 days, mg/m 2 ) g Cu ( 1% of simulation over RSL) g Cl - ( 2% of simulation over RSL) 4. Leaching tests at pilot scale carried out during limited natural exposure duration (e.g. 1 year) g Cu ( 9% of simulation over RSL) g Cl - ( 50% of simulation over RSL) 5. Simulation of leaching behaviour at pilot scale over 1 year g Cu ( 9% of simulation over RSL) g Cl - ( 50% of simulation over RSL) 6. Simulation over the whole reference service life of the product (30 years of use) g Cu (100% of simulation over RSL) g Cl - (100% of simulation over RSL) 11

12 Optimal use of data 12

13 Further steps A more complete and realistic evaluation: At the level of LCA, time dependent evaluations could be possible the time dependent LCA is a current research issue Evaluation of the local impact of the built environment e.g. by coupling the leaching models with toxicology tools 13

14 Leaching of construction products during their use stage: proposal for a reliable life cycle inventory (LCI) of the released substances in water and soil Maria LUPSEA, Nicoleta SCHIOPU, Ligia TIRUTA-BARNA Thank you for your attention! Session: LCI data: validation, aggregation and uncertainties CONTACT : maria.lupsea@cstb.fr