1. T3.1.4.A2
Preparation and refining technologies of recovered materials from the stony fraction for the manufacturing of green concretes and low-embodied energy cements
LAFARGE & TECNALIA

2. ST3.1.4
Objective: To create robust and cost-effective innovation in concrete recycling fostering feasible circular economies for C&DW material, setting the basis for implementation and standards for recycled concretes
Two approaches:

3. Approach A1
New concrete manufactured with refined recycled coarse concrete aggregates (TUD, MEBIN, INASH)
Concrete recipes = f (properties, processing, sensor techniques)
Mechanical and durability properties
Modelling

4. Approach A2
New concrete manufactured with selected recycled concrete coarse aggregates and partial incorporation of recycled concrete and ceramic fine aggregates, and low-embodied energy cements (TECN, LAFAR)
Use of low embodied energy cements
Use of low embodied energy cements with recycled aggregates

5. ST3.1.4.A2 Experimental planning
Methodology for new low-CO2 footprint cements containing C&DW inorganic fractions (fine recycled concrete fractions, recycled ceramic fractions, and recycled glass)
Three materials:
Brick waste (actually clean burnt clay bricks provided by Vito)
Concrete waste fines collected by LafargeHolcim. Concrete waste have been crushed to 20mm and sieved at 4 mm in an attempt to enrich in paste fraction. Not surprisingly, this enrichment is limited, as the crushing is not able to separate aggregate and paste fraction
Float glass waste collected previously by LafargeHolcim
Two fineness have been produced for brick and concrete waste
D50 = 15 µm, i.e. usual particle size of a standard cement
D50 = 7 µm, i.e. particle size of an ultrafine grinding in high performance industrial mill shop
The float glass will be used only at high fineness

6. ST3.1.4.A2 Experimental planning
Methodology for new low-CO2 footprint cements containing C&DW inorganic fractions (fine recycled concrete fractions, recycled ceramic fractions, and recycled glass)
TESTING PROGRAMME
The target defined is to produce CEM II/A 42.5, with up to 20% waste material
This initial step is to test the mortar properties of mixes of a standard CEM I and 20 % of waste, to assess the strength activity index and the workability index of each sample at each fineness
From those index, it is possible to estimate the behavior of ternary sample at various addition rate. Some possible mix can be designed to achieve the target of CEMII/A 42.5
Final validation of those mixes will then be tested
Additionally, test of real waste sample coming from electrofragmentation process will be tested (date to be confirmed)
Meanwhile, bigger batches of ground addition will be produced.

7. ST3.1.4.A2 Experimental planning
Methodology for new low-CO2 footprint cements containing C&DW inorganic fractions (fine recycled concrete fractions, recycled ceramic fractions, and recycled glass)
After the tests, three cement recipes will be proposed:
Recycled CEM II A 42.5 with ground recycled concrete (RECEM #1);
Recycled CEM II A 42.5 with ceramics (RECEM #2);
Recycled CEM II A 42.5 with glass (RECEM #3).

8. ST3.1.4.A2 Experimental planning
Methodology for new green concrete recipes
Design of concrete:
Compressive strength class:
Choose 1: C20/25; C25/30; C30/37
Types of specimens: cubes
Exposure condition: XF1
Target slump: S3
Types of cement: CEM II. Control + RECEM #1, #2, #3
Coarse aggregates
(4-12/12-20mm)
Fine aggregates
(0-4mm)
TECN
ACC
C-0-0 (Ref)
100% natural x
C-0-10g
10% recycled concrete
C-0-10r
10% recycled ceramic
C-0-20g
20% recycled concrete
C-0-20r
20% recycled ceramic
C-65-0
65% recycled concrete
C-65-10g
C-65-10r
C-65-20g
C-65-20r
C-100-0
100% recycled concrete
C g
C r
C g
C r
Intermediates? ?
March & April

9. ST3.1.4.A2 Experimental planning
Methodology for new green concrete recipes
April-May: Workability and compressive strength at 28d/90d(puzolanic) for all the formulations
July-August: Selection of best formulations and replycation with HISER cements
September-October: Full testing of new green concretes:
Workability, shrinkage, compressive strength, elastic modulus and durability (scaling freeze-thaw cycles)