21 January 2021 SeRaMCo Digital final conference

Use of recycled aggregates for production

André LECOMTE Laury BARNES-DAVIN Cécile DILIBERTO Amor BEN-FRAJ Breffni BOLZE Romain TRAUCHESSEC Nacef TAZI Arnaud DELHAY Hichem KROUR Outline

Introduction

I. Laboratory experiments

II. Industrial production

III. Durability

Conclusion

2 Introduction

Clinker

Natural materials Cement raw meal (CRM)

Recycled aggregates Firing

3 Introduction

SiO 2 Max incorporation rate 10-12% Varies widely (10 à 94)% Recycled aggregates incorporation 12-15% rate1,2 10% 15-20% Impacted by the Silicium-Calcium couple 20-30% 30-50% >50%

Depends also on: Cement raw meal • Type of cement plant quarries 94%

• Chemical composition of natural materials CaO + Al2O3 + MgO Fe2O3 • Type of clinker/cement produced

10% of calculations ► < 5% Incorporation rate of at least 5% is possible for 73% of calculations ► 10 to 30% 17% of calculations ► > 30% 90% of calculations

1. H. Krour et al, (2020) «Incorporation rate of recycled aggregates in cement raw meals » Construction and Building Materials. 4 2. H. Krour, (2020) «Incorporation des déchets de construction et de démolition dans le cru cimentier » PhD Thesis (in French). I. Laboratory experiments Laboratory synthesis of cement raw meals (CRM)

Ref GM1-N CT 40 Compared to reference CRM

30 Reduced burnability

(EDTA, %) (EDTA, 20 40 Highest free lime 37 36 35 34 32 Changes on intermediate 31 31 content 28 contenct 10 19 20 21 phases

0 100 Free lime lime Free 1000 °C 1050 °C 1100 °C 1200 °C Ref 60 80

) GM1-N

u.a CT 50 60 40 40 Alum.

Fer. (Rietveld, %) (Rietveld, Lower belite ( Intensity Geh. 30 20 content 50 53 50 50 ontent 44 43 45 44 0 20 36 37 34 30 31 32 33 34 35

Belite Belite 10 2θ (°)

0 5 1000 °C 1050 °C 1100 °C 1200 °C I. Laboratory experiments Laboratory synthesis of cement raw meals (CRM)

18 Higher belite contents 16 Ref GBR GM RB-CT 14 Reference 100% CaO 12 Variation of CRM Ferrite 10 80% Aluminate 16 burnability 8 15 15 16 60% 6 40% 4 8 7 6 6 5 20% 2 3 4 4 3 3 2 2 Bélite

Free lime content (EDTA, %) (EDTA, content lime Free 0 0% 1200 °C 1300 °C 1400 °C 1450 °C 1200 1300 1400 1450 Firing temperature Temperature (°C) GBR GM RB-CT 100% 100% 100% CaO Ferrite CaO Ferrite CaO Ferrite 80% Aluminate 80% Aluminate 80% Aluminate 60% 60% 60% Alite Alite Alite 40% 40% 40% 20% 20% 20% Bélite Bélite Bélite 0% 0% 0%

1200 1300 1400 1450 1200 1300 1400 1450 1200 1300 1400 6 1450 Temperature (°C) Temperature (°C) Temperature (°C) I. Laboratory experiments Study of the cement raw meals fineness

Residu @125 µm Residu @40 µm 40

30

20 Same fineness for all raw

Wt. (%) Wt. 37 31 34 35 35 34 34 34 meals 10 9 11 10 10 9 10 10 10 0 Ref GBR-T GBR-V GM1-T GM-V GM1-N RB CT 7 Quartz>40 µm (%) Feldspaths>40 µm (%) Mullite>40 µm (%) 6

5 1,0 2,0 1,6 1,9 2,2 4 2,8 2,2 0,4 High quartz and feldspars 3 contents 2 4,3 0,2 3,8 3,6 3,3 3,3 2,5 2,6 1 1,9 0 7 Ref GBR-T GBR-V GM1-T GM-V GM1-N RB CT I. Laboratory experiments Study of the reactivity of quartz and feldspars in the kiln

Feldspars in cement raw meal

Recycled aggregates used for the first industrial trial contain high proportions of quartz and K-feldspars

Silicium Potassium Calcium 8 I. Laboratory experiments Study of the reactivity of quartz and feldspars in the kiln

Quartz in cement raw meal @ 1200 °C Feldspar in cement raw meal @ 1200 °C

Belite Belite

WollastoniteIntermediate + liquid phase Quartzamorphous phase Feldspar C2S CS + liquid C2S + liquid Amorphous phase

CaO Quartz CaO CaO Feldspar CaO

Both minerals are still present @ 1200 °C = Modification of raw meal burnability 9 I. Laboratory experiments Characterization of industrial clinkers

Reference Alite Belite Ferrite Aluminate tricalcium 60

40 Wt. % Wt. 70 66 68 20 6 14 11 3 13 11 14 12 3 0 Reference First trial Second trial First trial Same mineralogical composition

100 Alite Belite 80 60 40 74,1 51,0 48,6 43,7 52,1 Second trial 20 29,0

0 Mean diameter (µm) diameter Mean Reference First trial Second trial Regular size of alite and belite grains 10 Similar reactivity hydraulic Cumulative heat (J/g) Cumulative heat (J/g) 100 150 200 250 300 100 150 200 250 300 350 400 50 50 0 0

12 68 Reference 12

60 Reference 24 61 Age Age (hours) Age (hours) Characterization 48

171 I. 24

First trial 151 Laboratory 72 157 First trial

96 234 48 219 Second trial 120 238 Second trial 144 248 72 249 of 168 industrial 261 experiments Cement Cementpaste mortars I. Laboratory experiments Characterization of industrial cements

12

10 Reference 8

6 First trial

4 Flexural strength(MPa) Flexural Second trial 2

0 1 2 7 28 90 180 365 Similar mechanical Age (days) 90 80 properties 70 Reference 60 50 First trial 40 30 Second trial 20 Compressive strength (MPa) strengthCompressive 10 0 1 2 7 28 90 180 365 Age (days) Conclusion Laboratory experiments

→Industrial trials and laboratory synthesis confirm clinker quality but …

Use of RAs at high incorporation rate = higher quartz and feldspars content in the raw meal for (d>40 µm) ✓ Study for better understanding of quartz and feldspars reactivity in the kiln

C2S CS + liquid C2S + liquid Amorphous phase

CaO Quartz CaO CaO Feldspar CaO

Both minerals are still present @ 1100-1200 °C

= Modification of raw meal burnability 13 II. Industrial production

VICAT cement plant in Créchy, France 14 II. Industrial production (Créchy cement plant)

Last cement plant greenfield in 70 workers France Raw material substitution : Open 24/7 Built in 1968 The plant is substituing 10% of natural ressources ( and marl) thanks to the valorisation of mineral by-products coming from other industries Leader in reducing the consumption of 2018 Innovation fossil fuel Commisioning of a > 80% of the energy gasifier needed for the burning is A world first!!! produced thanks to alternative fuel Raw materials Fuels

Natural Alternative Fossil Alternative • Limestone • Foundry sand • Charcoal • Waste wood • Marl/ clay • Ashes • Petcoke • Bauxite • Iron oxydes • Oil / Solvents • Heavy oil • Iron ore • Excavated soil • Animal meal • Gas • • Plasterboard • Tires • Etc. • Dried sewage sludge • Etc.

10 4 8

2 6

3 5 7 9 1

• 1: Quarry • 6: Kiln • 2: Pre-homogenisation pile • 7: Cooling • 3: Raw feed mill • 8: Storage • 4: Storage • 9: Cement mill • 5: Pre-heater Tower • 10: Storage, packing, loading Créchy cement plant

Alternative raw materials:

Alternative fuels: Créchy cement plant 2 full-scale trials

➢1st trial, September 2018, production of 3,000 t of clinker ➢ Raw materials included 14.2% of recycled aggregates ➢ Over-consumption of energy (~20%) ➢ Impact on the quality of the clinker ➢ Production of 5 t of cement for SERAMCO partners

➢2nd trial, July 2019, Production of 2,500 t of clinker ➢ Raw materials included 5.2% of recycled aggregates ➢ No over-consumption of energy ➢ Good quality clinker ➢ Production of 55 t of cement for SERAMCO partners

18 ➢ Stacking of raw material including 4.6% “mixed fines” delivered by TRADECOWAL (271 tons), equivalent to an annual consumption of ~50 kt/yr ➢ Pre-homogenisation

Costa et al, Jan 07 Reserchgate 19 ➢Milling of the pre- homogenisation pile ➢Final adjustment of the chemistry by adding bauxite and iron oxide ➢Storage and homogenisation of the raw feed ➢Firing of the raw feed

20 ➢Production of 2,500 t of clinker ➢ Good quality clinker ➢ No over-consumption of energy ➢ 65% C3S ➢ 1.67% free lime

➢Storage in Créchy before transfer to VICAT R&D pilot center in Chambéry, France

21 • R&D ball mill pilot ➢ Same sulfate source and VICAT R&D plant in Chambéry, France content (former cement plant) ➢ Comparable fineness: measurement of Blaine fineness and PSD

• Production of 55 t of CEM I 52,5 N : ➢35 t PREFER ➢14.5 t BETON BETZ ➢3 t TU KL ➢2 t TU Delft ➢0.4 t Uni Liège ➢0.2 t Uni Lorraine

22 III. Durability

23 III. Durability Mechanical properties of

24 III. Durability Durability parameters of concrete

25 Thanks for your attention! Questions? 26