1. New recycled aggregates with enhanced
performance for railway track bed and form layers
Mr. Valentí Fontserè, COMSA, Spain
Motivation
High volume of black slag generated in Europe
Iron / Blast Furnace Slag
Basic Oxygen Furnace(BOF)
Ferrous slag
Black slag
Steel Furnace Slag(SFS)
Electric Arc Furnace(EAF)
White slag
Valorisation of EAF slag
Development of a new product: SFS-Rail
Main features of SFS-Rail
New recycled aggregate from black EAF slag used in the sub-ballast and sub-grade rail track foundation layers
High abrasion resistance
Higher lateral resistance
High drainage capacity
Prevents unwanted vegetation
Chemical/ weathering resistance
High electrical resistance
SFS-RAIL
Added value of SFS-Rail
SFS recognised by international standards (Brazilian standard, EN norm, UIC code…)
Lower slag storage volumes
Reduction of quarries impact and CO2 emmissions
Competitive cost
SFS-Rail characterisation
Requirements to be used in sub-ballast and sub-grade layers fulfilled
Granulometry of the mix
(75% slag aggregate + 25 % limestone)
Mechanical tests
Granulometry of the slag aggregate
Los Angeles coefficient similar to natural aggregate (15-20).
High abrasion resistance: Micro-Deval <20 and CP
100% of fracture faces  good interlocking among particles.
Accelerated expansiveness of 0.3% after 168 hours.
Addition of natural limestone
Chemical tests
Need of fine material
Leaching tests
Tests according to EN 12457: SFS-Rail under water, monitoring of constituents detachment
Demonstration in a field test
Development of a calculation software
Optimal solution by automatic iteration
Track degradation model
Validation and calibration with the field tests
Construction and monitoring of a field test with SFS-Rail in the subballast and subgrade layers in a mixed line of ADIF’s (Spanish IM) network
Measurement of the track settlement, stress distribution and instant deflection during passage of trains
Comparison with a test section
Other achievements of the project
Life Cycle Assessment (LCA)
Environmental Impact Assessment (EIA)
Elaboration of a SFS-Rail Quality Control Plan
Confection of track solutions catalogue
Socioeconomic impact of the project