Sustainable Concrete Design

•   ·

•   Lowering CO2 in
    Construction

• CO2 Construction Audit

• Elegance in Architecture



David Bennett
Architectural Concrete Consultant
Picture a Glass of Latte
        What’s the Embodied C02?

•   Raw Material
•   Production
•   Packing
•   Transport
•   Shop
•   Hot Water
•   Coffee Container
•   Milk
•   Sugar
Concrete and C02
It’s just like a good cup of coffee


Expresso, Americano, Latte, Macchiato,
 Mocha

Insitu, Precast, SCC, GRC, Ductal, Rammed


                     Discuss
C02 and Concrete Construction

               • Cement
               • Aggregates
               • Ready Mix
               • Rebar
               • Formwork /Temporary
                 Work
               • Plant & Machinery
               • Labour
Concrete
      Cement is one sixth of concrete


                    kg C02/tonne

•   OPC     range   930 > 760
•   GGBS            54
•   PFA              4
•   Rocktron        50
Persistence Works
Lowering Cement C02 by 50%

• Blend OPC with GGBS/PFA

• Carbonation Benefits of OPC
Aggregates are 80% of Concrete
  Aggregates                  kg C02/tonne

• Natural Washed -              4
• Natural Crushed -             4-10


 Synthetic Aggregates
• Lytag Sintered PFA           60
• Liapor   (expanded shale)    12
Typical Concrete Mix
             Constituents

                                       kgC02/m3
OPC       180 kg      Ribblesdale      137
GGBS      180 kg      C&M                8
Sand      750 kg      Lea Valley        3
Gravel    1200 kg     Thames Estuary     5
Water      180 kg     Thames Water      0
Admixture ignore

                Embodied kg C02/m3     153
CO2 of Wood

Captured CO2 = 1.84 x density

Embodied CO2
Process plywood                     670 kg C02/tonne
Wisa – birch phenolic faced
18mm thick                           29 kg CO2/m2
(assumes the wood is carbon zero)
Formwork

  Temporary Support/
  Falsework
  Disposable Items
• Form Face Ply
  18mm thick
• Plastic Cones
• Tie Rods
The Form Face & Sustainable
              Design

•   Select Material for a Good Finish
•   High Reuse Factor
•   FSC Grade
•   Re-use in Permanent Architecture
•   Responsible Design
Rebar C02
                                            kg C02/tonne   Total
Two Stage Process
1. Coil Manufacture                                  422
2. Fabrication
   a) Bar                                            63     485
   b) Mesh                                           88     501


Celsa/ BRC Audit
  includes production , staff travel and transport
Concrete Quality and
          Aesthetic

• Visual Concrete Specification
• the choice, the mix, the form, the finish

                Get it right!
Thrifty Beeches
Spedant Works
Kew Herbarium
CHUR House
The C02 Construction Audit

Four Buildings Assessed
two concrete, two steel


•   Bill of Quantities
•   Embodied C02 of Materials
•   Plant/Machinery/Labour
Some Anomalies
   Some references are distorted

• Resin, Polyurethane, Paint, PVC
       resolve micron/m2
• Structural Steel
         new or recycled? check
• Lightweight Lytag Concrete
         high C02/m3

           RECONCILE them
Construction Audit Examples

•   Substructure
•   Superstructure
•   External Cladding
•   Finishes
•   Mechanical Ducting
Building CO2 Audit Summary


Element                      M4C3    %         M4S3        %       M4C7    %     M4S7    %


Substructure                  136        10           95       4     254   9      160    3

Superstructure                350        27     1348       59       904    31    3411    63
External cladding             263        20       267      11        532   18     545    10
Finishes                      432        33       433      19        893   31     911     1
M&E: Fully air conditioned     59         4           59       3     137    5     137     3
Plant & labour                 83         6           89       4     190   6      189     4


Total (av.)                   1322       100      2291     100       291   100    5353   100
Tonnes CO2
Building CO2 Audit Summary
        Possible reductions in CO2 for lean solution


Element                  M4C3   %    M4S3    %     M4C7     %     M4S7     %


Frame -                   na          -768           na           -1972
All recycled steel

M&E;
a) eliminate suspended    -60         na            -149           na
   ceiling
b) Reduce ductwork        -53         na            -124            na

Public transport          -77         -83            -183          -182


Total CO2 reduction       -190 -14   -851    -37   -455     -16   -2154   -40
Total C02 Design Solution


• Minimise Construction C02
• Utilise Thermal Mass for Long Term
  Energy Reduction


 Lower Total C02 Emissions
Concrete is just like a good coffee -

      Make it the low C02 blend!

Sustainable concrete design and construction

  • 1.
    Sustainable Concrete Design • · • Lowering CO2 in Construction • CO2 Construction Audit • Elegance in Architecture David Bennett Architectural Concrete Consultant
  • 2.
    Picture a Glassof Latte What’s the Embodied C02? • Raw Material • Production • Packing • Transport • Shop • Hot Water • Coffee Container • Milk • Sugar
  • 3.
    Concrete and C02 It’sjust like a good cup of coffee Expresso, Americano, Latte, Macchiato, Mocha Insitu, Precast, SCC, GRC, Ductal, Rammed Discuss
  • 13.
    C02 and ConcreteConstruction • Cement • Aggregates • Ready Mix • Rebar • Formwork /Temporary Work • Plant & Machinery • Labour
  • 17.
    Concrete Cement is one sixth of concrete kg C02/tonne • OPC range 930 > 760 • GGBS 54 • PFA 4 • Rocktron 50
  • 18.
  • 19.
    Lowering Cement C02by 50% • Blend OPC with GGBS/PFA • Carbonation Benefits of OPC
  • 20.
    Aggregates are 80%of Concrete Aggregates kg C02/tonne • Natural Washed - 4 • Natural Crushed - 4-10 Synthetic Aggregates • Lytag Sintered PFA 60 • Liapor (expanded shale) 12
  • 21.
    Typical Concrete Mix Constituents kgC02/m3 OPC 180 kg Ribblesdale 137 GGBS 180 kg C&M 8 Sand 750 kg Lea Valley 3 Gravel 1200 kg Thames Estuary 5 Water 180 kg Thames Water 0 Admixture ignore Embodied kg C02/m3 153
  • 23.
    CO2 of Wood CapturedCO2 = 1.84 x density Embodied CO2 Process plywood 670 kg C02/tonne Wisa – birch phenolic faced 18mm thick 29 kg CO2/m2 (assumes the wood is carbon zero)
  • 27.
    Formwork TemporarySupport/ Falsework Disposable Items • Form Face Ply 18mm thick • Plastic Cones • Tie Rods
  • 30.
    The Form Face& Sustainable Design • Select Material for a Good Finish • High Reuse Factor • FSC Grade • Re-use in Permanent Architecture • Responsible Design
  • 33.
    Rebar C02 kg C02/tonne Total Two Stage Process 1. Coil Manufacture 422 2. Fabrication a) Bar 63 485 b) Mesh 88 501 Celsa/ BRC Audit includes production , staff travel and transport
  • 39.
    Concrete Quality and Aesthetic • Visual Concrete Specification • the choice, the mix, the form, the finish Get it right!
  • 40.
  • 42.
  • 44.
  • 46.
  • 47.
    The C02 ConstructionAudit Four Buildings Assessed two concrete, two steel • Bill of Quantities • Embodied C02 of Materials • Plant/Machinery/Labour
  • 48.
    Some Anomalies Some references are distorted • Resin, Polyurethane, Paint, PVC resolve micron/m2 • Structural Steel new or recycled? check • Lightweight Lytag Concrete high C02/m3 RECONCILE them
  • 49.
    Construction Audit Examples • Substructure • Superstructure • External Cladding • Finishes • Mechanical Ducting
  • 50.
    Building CO2 AuditSummary Element M4C3 % M4S3 % M4C7 % M4S7 % Substructure 136 10 95 4 254 9 160 3 Superstructure 350 27 1348 59 904 31 3411 63 External cladding 263 20 267 11 532 18 545 10 Finishes 432 33 433 19 893 31 911 1 M&E: Fully air conditioned 59 4 59 3 137 5 137 3 Plant & labour 83 6 89 4 190 6 189 4 Total (av.) 1322 100 2291 100 291 100 5353 100 Tonnes CO2
  • 52.
    Building CO2 AuditSummary Possible reductions in CO2 for lean solution Element M4C3 % M4S3 % M4C7 % M4S7 % Frame - na -768 na -1972 All recycled steel M&E; a) eliminate suspended -60 na -149 na ceiling b) Reduce ductwork -53 na -124 na Public transport -77 -83 -183 -182 Total CO2 reduction -190 -14 -851 -37 -455 -16 -2154 -40
  • 57.
    Total C02 DesignSolution • Minimise Construction C02 • Utilise Thermal Mass for Long Term Energy Reduction Lower Total C02 Emissions
  • 61.
    Concrete is justlike a good coffee - Make it the low C02 blend!