I. Papayianni, E. Anastasiou, M. Papachristoforou Laboratory of Building Materials Aristotle University of Thessaloniki Greece Mixed type binding systems. A sustainable alternative for RCC Pavements V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow

Background Binders are the most precious materials in building construction, since they transform a volume of grains into a compact, load-bearing material of adequate volume stability Portland cement is an excellent high-strength binder which predominates in construction, but is also an energy consuming, high-cost material of low ecological profile Under the pressure of reality: Climatic changes and catastrophes Global economic depression Need of longer service life for constructions There is an urgency to develop alternative smart mixed type binding systems V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Background A first simple step for sustainability integration in construction is to make local industrial by-products (fly ashes, slags) beneficial for the structural sector How do we work to exploit industrial by-products to the maximum: Test the suitability of the by-products as cementitious materials for a specified use Development of a mixed type binding system and assessment of its quality Design and proportioning of a proper concrete mixture for a specified strength Test the compliance of the concrete with a control mixture Proceed to a pilot application of the designed concrete Measure the concrete performance and the long term characteristics on site V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

The construction of a RCC road pavement with a fly ash-based binding system Stakeholders: Aristotle University of Thessaloniki (responsible for research and consultancy) National Technical University of Athens TITAN Cement Industry EGNATIA ODOS S.A. TERNA Construction Company Project: TEFRODOS Funds: General Secretary of Research and Technology, Greece V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

In Greece, only asphaltic concrete has been used for road pavements There is no tradition in bedding concrete road pavement The RCC pavement alternative seems to be the most feasible solution The main advantages for such a solution are: Longer service life and lower cost of maintenance Reduced environmental footprint V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki The construction of a RCC road pavement with a fly ash-based binding system

Stronger and resistant to heavy truck circulation (RCC pavements are recommended for interchange ramps and heavy truck traffic in hot climates) Reduction of thermal emissions Light reflectivity V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki The construction of a RCC road pavement with a fly ash-based binding system Infrared photgraphy of the Atlanta Hatfield Airport (property of NASA) where asphalt parking lots develop higher temperature compared to concrete parking lots

The initial construction cost of a concrete road is slightly higher than that of asphaltic concrete By using fly ash-based hydraulic binders the cost is significantly reduced V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki The construction of a RCC road pavement with a fly ash-based binding system

Development of the mixed type binder and quality assessment Aim: 28-d compressive strength of 40 MPa, so as to have on site at least 30 MPa Materials (% by mass) Calcareous fly ash 50% Clinker 25% Natural pozzolan 12.5% Limestone filler 12.5% Test measurements: Fineness Grinding time Water demand Setting time Le Chatelier volume stability Compressive strength at 2, 7 and 28 days V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki  Blended mixed type binder Testing according to EN for Hydraulic Road Binders

Characteristics of the constituents of the hydraulic binder developed V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki Content/ Property Cement clinker Calcareous fly ash Limestone filler Natural pozzolan SiO 2 (%) Al 2 O 3 (%) Fe 2 O 3 (%) CaO (%) MgO (%) CaO free (%) n/a SiO 2-reactive (%)n/a*n/a SO 3 (%) L.O.I. (%) Insoluble residue (%)

Properties of the produced mixed type hydraulic binder V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki Physical properties Blaine (cm 2 /g)9550 Fineness (retained at 45 μm)0.4 Water requirement (%)41.5 Initial setting time (min)210 Le Chatelier dilation (mm)0.0 2-day compressive strength (MPa) day compressive strength (MPa) day compressive strength (MPa)40.1 Chemical properties L.O.I. (%)8.40 SO 3 (%)3.20 Insoluble residue (%)26.40 CaO free (%)4.80 Chemical analysis SiO 2 (%)29.90 Al 2 O 3 (%)12.65 Fe 2 O 3 (%)3.80 CaO (%)42.90 MgO (%)2.20

Proportioning RCC with fly ash-based hydraulic binder “Tefrocement” Required strength: f ck C25/30 Maximum Vebe density (according to ACI R-95) with Vebe time: 20-40s Available aggregates: Crushed limestone of maximum size 31.5 mm or 16 mm “Tefrocement” quantity: ≤ 300 kg/m 3 Water/cementitious ratio: ≤ 0.50 V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

The proposed aggregate gradations V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Trial mixes series A and B V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki MixtureA1A2A3A4B1B2B3B4 Hydraulic Road Binder (kg/m 3 ) Water (kg/m 3 ) Fine aggregate (kg/m 3 )1096 Coarse aggregate (kg/m 3 )897 Max. aggregate size (mm) superplasticizer (%wt. of binder)0.0%1.0% 0.0%1.0% 0.5% w/cem Vebe time (s) Vebe density (kg/m 3 ) Electrical hammer density (kg/m 3 ) d compr. strength (MPa) d compr. strength (MPa) Decision to use 280 kg/m 3 “Tefrocement”

New series of laboratory test mixtures series A and B, accounting for transport time V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki MixtureA5A6B5B6 Hydraulic Road Binder (kg/m 3 )280 Water (kg/m 3 ) Fine aggregate (kg/m 3 ) Coarse aggregate (kg/m 3 ) Maximum aggregate size (mm) superplasticizer (%wt. of binder)0.0%0.5%1.0%0.0% w/cem Vebe time (s), t=0' Vebe time (s), t=30' Vebe density (kg/m 3 ), t=0' Vebe density (kg/m 3 ), t=30' Electrical hammer density (kg/m 3 ), t=0' d compressive strength (MPa) d compressive strength (MPa)

Pilot construction Ground layer with CBR ≥ 18 Concrete plant at 30 minutes driving distance Continuous feeding of the paver Compaction achieved by rollers Measurement of compaction with Humboldt nuclear gauge V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Truck loading V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Truck unloading onto paver V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki Difficulty unloading truck due to delay in transportation

Laying RCC V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Laying RCC V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Roller compaction of pavement V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Fresh concrete density measured with nuclear gauge V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Achieved compaction Only with the paver, the compaction achieved was 80% V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki depthdirectly after the paverafter compaction 5 cm81.8%90.4% 10 cm81.2%91.3% 15 cm81.0%90.6% 20 cm79.7%89.3% average total pavement thickness (cm) -22.1

Effective compaction scenarios 3 non vibrating passes with a 4 ton roller 2 vibrating passes with a 10 ton roller Maximum single layer thickness achieved: 20 cm V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Joints Shrinkage joints: cut every m after hardening, to a depth corresponding to 1/4 - 1/3 of the road thickness V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Joints Thermal dilation joints V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki Source: Cement and Concrete Association of New Zealand, "Concrete ground floors and pavements", Part 1

Survey of concrete pavement 2 months after construction Core drilling and testing Mechanical properties Freeze-thaw resistance (-25°C to +20°C) V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

Survey of concrete pavement 2 months after construction Mechanical properties of drilled cores V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki Construction area (average of 6)123 pulse velocity u (m/sec) density ρ (kg/m³) Compressive strength f c (MPa) Continuous monitoring of the test road

Conclusions The construction of a RCC road with this mixed type binder is feasible The technical problems that appeared were properly confronted The long term strength and resistance were adequate in order to guarantee a long service life The incorporation of a low cost industrial by-product into a hydraulic binder contributes essentially towards lowering the initial cost of a concrete road, rendering this sustainable alternative also cost-effective. V International Conference ASHES FROM TPPS – Removal, Transport, Processing, Storage April 23-25, 2014, Moscow Laboratory of Building Materials - Aristotle University of Thessaloniki

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