Concrete Technology

from Grey to GreenConcrete

Concrete from Grey to Green B

Gammon Construction Limited has been involved in a wide range of construction projects in Asia for over 50 years. We are the market-leading construction contractor in Hong Kong, where we are headquartered, and also operate in China and Southeast Asia.

In 1980, Gammon established a department to produce ready-mixed concrete that adds value for our customers. A trademark was registered to characterise the departments products and services.

The department provides a variety of concrete solutions to customers. We also combine concrete mix design and production control technology to offer the best optimised concrete solutions to customers concerned about sustainable development.

Concrete from Grey to Green 1

Concretes carbon footprint

Concrete is the most widely used construction material in the world.

The production of concrete, which requires the addition of cement, generates carbon dioxide, a greenhouse gas that contributes to global warming. A small reduction of 10% in the consumption of cement can make a significant difference in protecting the environment.

Compared to conventional concrete mixes, the cement content of Gammon Green Concrete is typically 10% lower.

1 Hysan Place is the first building in Hong Kong to achieve pre-certification of the highest Platinum level under LEED (Leadership in Energy and Environmental Design) of the US Green Building Council

2 This residue concrete recycling system used by Gammon is a compact system that washes, separates and dewaters concrete, and discharges sand and aggregate separately

3 On the Hysan Place project, concrete raw materials used for construction were all manufactured within 800km to minimise the impact on the environment

Concrete Production

80 Tonnesper month

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Concrete from Grey to Green 2

Gammon Green Concrete (GGC) is a high-performance concrete family that has been developed to minimise its carbon footprint and increase durability.

GGC is designed to optimise the packing density of all the solid particles, including cementitious materials and aggregates, so that the least amount of ordinary Portland cement or cementitious materials can be used.

Supplementary cementitious materials (essentially waste from the generation of electrical power or other manufacturing processes) are also added to further reduce the amount of cement.

Both the addition of supplementary cementitious materials and the optimisation of packing density substantially reduce the absorptivity and permeability of concrete, thereby improving the durability of the concrete structures such as buildings, bridges and tunnels.

Green solutions from Gammon

CarbonReduction

10%

Concrete from Grey to Green 3

Cumulative particle size distribution of concrete constituent materials

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Particle size

Ordinary Portland cementFly ash Condensed silica fume20mm aggregate

10mm aggregate Crushed rock fines River sand

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Theoretical optimal packing curve Actual mix design

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Example of optimising the packing density of grade 100 MPa high-performance concrete

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Ordinary Portland cementFly ash Condensed silica fume20mm aggregate

10mm aggregate Crushed rock fines River sand

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0.1

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Theoretical optimal packing curve Actual mix design

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Combined cumulative particle size distribution of grade 100 MPa high-performance concrete

Concrete from Grey to Green 4

Cumulative Present Value

Gammon Green Concrete typical properties

GGC typically has a chloride diffusion value of lower than 2000 coulomb. When needed, the concrete can be formulated to reduce the chloride diffusion value to 500 coulomb or less. As a result, more durable buildings cut maintenance costs significantly and their service life could be extended well beyond 50 years the normal service life of buildings in Hong Kong.

Life cycle cost comparison

1 The self-consolidating concrete used for the Hong Kong Shenzhen Western Corridor project is capable of being transported over longer distances more economically

2 The Hong Kong Shenzhen Western Corridor

3 Gammons concrete batching plant

4 The cable-stayed tower for the Hong Kong Shenzhen Western Corridor

20,000

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/mC

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m)

45/20D normal PFA concrete100/20D high-performance concrete

HK$35,047.94/m45/20D normal PFA

concreate

HK$27,932.57/m100/20D

high-performance concrete

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Concrete from Grey to Green 5

Product range

A full range of GGC specificationsIn the GGC family, concrete mixes have a carbon footprint per unit volume not higher than 380 kg carbon dioxide equivalent.

The different types of GGC include various high-performance concretes such as flowing concrete, high-strength concrete, high-durability concrete, self-consolidating concrete and early strength concrete.

Concrete mixes can also be tailored for special applications upon request (2 months lead development time required).

Normal ConcreteNormal concrete products are designed for general purpose applications such as columns, walls, slabs, and caps of buildings and bridge structures.

These high quality products are manufactured to comply with local and international standards or specifications.

High-performance ConcreteGammons high-performance concrete products have been successfully applied in many technically-demanding projects in Hong Kong.

- Flowing Concrete (Slump 190 mm)

- Tremie Concrete

- Very Long Slump Retention Concrete (Slump retention 10 hours)

- Early Strength Concrete (Cube strength 10 MPa in 12 hours)

- Very Early Strength Concrete (Cube strength 12 MPa in 4 hours)

- High-Strength Concrete (Ranged from Grade 65 to 100 MPa with high workability)

- Self-Consolidating Concrete (Slump flow 700 mm)

- Crack Control Concrete

1 The pile cap works for the Hong Kong Shenzhen Western Corridor

2 Photomicrograph of Grade 100 MPa high-performance concrete showing enhanced aggregate-cement paste interface

3 One Island East is an example of a project constructed with Grade 100 MPa high-performance concrete. The high strength property of Grade 100 MPa concrete means less concrete or rebar are needed. As a result at One Island East, the reduction in carbon footprint per unit floor area per year of sevice due to the higher strength and durability of the high-performance concrete used is about 50%

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Concrete from Grey to Green 6

Harnessing technology

In 2003, Gammon introduced an advanced Global Positioning System (GPS) Mixer Truck Tracking System to manage its mixer truck fleet more efficiently. The system performs two basic functions: data transmission and data storage/analysis. This technology offers the following benefits:

Real-time information, updated every 30 seconds, available to the operation team

Timely and accurate delivery information assures better responses to customer enquiries and higher levels of customer satisfaction

Maximum efficiency

Reduced waiting time on site

Reduced communication time

Safer driving speeds

Accurate and reliable delivery of data

1 Gammons GPS concrete truck tracking system. Each truck is equipped with a GPS system to improve logistics

2 The mixer truck fleet on the road

3 Gammons mixer truck fleet

4 A mixer truck fleet delivering concrete on a barge during the construction of the Hong Kong Shenzhen Western Corridor

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Concrete from Grey to Green 7

Residue fresh concrete recycling

Gammon understands the importance of environmental protection and has adopted sustainable practices in every branch of its business. In Gammons concrete batching plant, the wastage from production and delivery is processed by the use of a two-stage recycling system:

Separation in the concrete reclaimer stage

Dewatering in the slurry dewatering machine stage

After processing, the wastage is separated into aggregates, dewatered slurry and water. All these materials can be re-used for other engineering purposes.

Send to local academicinstitution to investigate potential area for reuse

Reuse in cleaning

works

SlurryCake

SlurryWater

Slurry Dewatering Machine

1st Stage Treatment

2nd Stage Treatment

ResidueFresh

Concrete

Recycled for other engineering use

RecycledFine

Aggregates

RecycledCoarse

AggregatesSlurry

Concrete Reclaimer

Concrete from Grey to Green 8

Certified to the Quality Scheme for the Production and Supply of Concrete (QSPSC), ISO 9001, ISO 14001 and ISO 18001.

2007 Hong Kong Awards for Industries Technological Achievement Award.

2009 Occupational Safety and Health Award Excellent Performance in Hearing Conservation.

2009 Occupational Safety and Health Award Excellent Performance in Prevention of Pneumoconiosis.

2010 Occupational Safety and Health Council Good Housekeeping Promotional Campaign 2009/10 Merit Award.

Our award-winning operations

Reference projects

Major Civil Projects (over HK$1,000 Million)2003-2006 Hong Kong - Shenzhen Western Corridor, Hong Kong

2003-2006 Deep Bay Link - Northern Section, Hong Kong

2003-2008 Route 8, Nam Wan Tunnel and West Tsing Yi Viaduct, Hong Kong

2009-2013 Reconstruction and Improvement of Tuen Mun Road - Eastern Section, Hong Kong

2009-2014 MTR West Island Line, Kennedy Town Station and Overrun Tunnel,

Hong Kong

Major Building Projects (over HK$1,000 Million)2003-2005 Bellagio Phase 2, Hong Kong

2006-2008 One Island East, Hong Kong

2007-2009 iSQUARE, Hong Kong

2008-2011 Tamar Development Project, Hong Kong

2009-2012 Hysan Place, Hong Kong

2009-2012 Centennial Campus, The University of Hong Kong

Major Foundations Projects (over HK$50 Million)2003-2006 Hong Kong - Shenzhen Western Corridor, Hong Kong

2003-2006 Deep Bay Link - Northern Section, Hong Kong

2005-2006 Mixed Use Development at Lot B, Zone B, NAPE, Macau

2006-2007 PPC Piling and Bored Piling for Zone 4, City of Dreams at Cotai, Macau

2007-2009 LPM & ELS Works for Centennial Campus, The University of Hong Kong

2008-2009 Tseung Kwan O Complex at Area 44, Hong Kong

2008-2010 Tseung Kwan O at Area 85, Site A, Lot 90, Hong Kong

2008-2011 Tamar Development Project, Hong Kong

2009-2010 Kai Tak Development Site 1A, Phase 1 & 2, Hong Kong

2009-2010 Proposed Composite Development at 3 Chun Yan Street, Hong Kong

2009-2010 Reconstruction and Improvement of Tuen Mun Road - Eastern Section, Hong Kong

For more information on our products or services, please contact:

Gammon Construction LimitedConcrete Technology Department21 Chun Wang StreetTseung Kwan O Industrial EstateHong Kong

Tel (852) 2110 1880Fax (852) 2964 0402

E-mail: concrete@gammonconstruction.com

is a registered trademark of the Concrete Technology Department under Gammon Construction Limited

Jointly owned by Jardines and Balfour Beatty