CO2 and Other Pollutants


Sustainable development can be defined as:

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Ecocem is sustainable because:

  • it is made by upcycling (as opposed to recycling) an industrial by-product.
  • it extends the life of your structures.
  • it significantly reduces the embodied CO2 of your structure.

Using Ecocem (GGBS) cement will ensure you are taking a very positive first step towards building a sustainable development.

The CO2 benefits have been discussed in a previous section. Under the definition of sustainable development as above, by reducing CO2 emissions we are helping fight climate change and thus not effecting future generations. The other two benefits are expanded in more detail below.

Natural Resources

Depletion of Natural Resources

In the production of Portland cement, 1.6 tonnes of clay/shale and limestone are removed from our landscape for every tonne of Portland cement produced. However, there is zero depletion of our natural resources associated with the manufacture of GGBS.

The raw material for GGBS production is an industrial by-product. This means no extraction of limestone or clay in large scale quarries that both deplete our natural resources and disfigure the landscape, and no associated traffic, noise and dust problems that are also generated by large-scale quarrying.

Concrete Service Life

Longer Service Life

The effect of GGBS on concrete durability means that the time to replacement of concrete products and structures is extended. Specifying GGBS to replace Portland cement in concrete is an essential requirement on all projects carried out under the aegis of sustainable development.

The longer service life of concrete containing GGBS reduces the demand on natural resources to meet the requirements of the construction industry. This applies to all ingredients in concrete: for every tonne of cement there are approximately 6 tonnes of sand/aggregates that also need not be replaced as long as the concrete remains in serviceable condition.

In short, extending the useful life of concrete has a major impact in reducing the demand for the extraction of new natural resources from the landscape, and is a significant contributing factor to sustainable development.

A Perspective on Recycling

Recycling Paper and Specifying GGBS in Concrete

Most organisations now have a policy of recycling paper. A little effort is required to set up such a system, but the organisation that recycles paper is happy to advertise this as a demonstration of its environmental credentials. Recycling paper has now become an established and accepted method of ‘saving the environment’.

However if we look more closely at the impact of paper recycling on CO2 absorption, and compare it to the role GGBS can play, the results are quite dramatic. The example below illustrates the point clearly:

  • 1 staff member in the average office recycles approximately 10 sheets of paper per day = 15 kg of paper per year1
  • 1 tree supplies 60 kg of paper2
  • 1 staff member recycling paper saves 0.25 trees per year
  • 1 tree absorbs 5–9 kg of CO2 per year3
  • Thus 1 staff member recycling for 1 year saves up to 2.25 kg of CO2
  • 1 staff member recycling for 10 years saves up to 121.5 kg of CO24
  • Thus 10 staff members recycling for 10 years will save only 1.2 tonnes of CO2
  • However, one single medium sized project using 5,000 m3 of concrete, with 50% GGBS specified in the mix, will save 728 tonnes of CO25
  • The average consulting engineer’s or architect’s office will handle maybe a half-dozen such projects in just one year
  • 728 tonnes × 6 projects × 10 years = 43,680 tonnes, a substantially greater CO2 saving than just 1.2 tonnes