With the introduction of Cem II in to the building product industry and the environment being a major concern, Hanson Formpave has successfully developed a more sustainable, environmentally-aware cement that has been used in the manufacture of its pavers for the last 10 years. This proves that the use of recycled materials does not mean compromising on quality.
As more and more specifiers are requesting the sustainable credentials of cements in their specifications, Hanson Formpave delivers the ultimate solution by ensuring that all of its products are manufactured using a 30% recycled GGBS content within its cement mix, akin to Cem II. The only exception is the Charcoal single colour block which in order to achieve its dark colour is manufactured using pulverised fuel ash (PFA), a recycled by-product produced by the firing process in coal burning thermo-electric power stations.
Compared to the traditional Cem I Portland cement, Cem II provides the important ‘green’ element. Hanson Formpave uses a mix of original Portland cement (OPC) and ground granulated blast furnace slag (GGBS) - a by-product from the steel industry used as a cement replacement and therefore counts as a recycled component to create its own cement mix. Cem II is normally sold as a pre-blended product but Hanson Formpave utilises its extensive silo capacity on its site in Coleford, Gloucestershire to house the seperate components and blends the mix itself. Hanson Cement, a sister company from within Hanson UK, is the only manufacturer of GGBS in the UK; in producing concrete using GGBS Hanson Formpave can reduce greenhouse gases by over 40% per cubic metre of concrete.
In blending onsite it is able to tailor the mix, so when the temperature drops and raises with the change in season the factory team is able to add more or less GGBS. A higher quantity of OPC is needed in colder weather to ensure that the mix cures in time for racking and packaging the blocks as GGBS has a longer setting time and this is exacerbated by the cold, damp conditions in the winter months. In warmer weather the ratio of recycled to OPC can be anything up to 50:50, compared to 30:70 in cold weather. Consequently this means that on average, per year the UK as a whole saves around three million tonnes of quarrying, reduces primary energy use by 2,000 million kWh and potentially saves landfill of two million tonnes.
Steve Jones, quality manager for Hanson Formpave explains more about the use of GGBS and the affect that this has had on the company’s environmental and quality initiatives. "Hanson Formpave started to explore the inclusion of GGBS in the manufacture of its paving products over 10 years ago, today it is used in the manufacture of nearly all of our products. GGBS produces a lighter coloured concrete and so cannot achieve the dark qualities needed to replicate our charcoal shade.
"As a company we are continually pushing the boundaries of development and we are constantly working to ensure that we can provide the ideal paving solutions as the global climate shifts and changes. Our use of an alternative, recycled by-product and our ability to tailor a Cem II mix was an integral part of our achieving the environmental management accreditation, ISO 14001, across all of the Hanson Cement and GGBS manufacturing sites. In addition, all sites also hold the ISO 9001:2008 accreditation for quality.
"Quality is one of a number of uncompromising factors in the products and service that Hanson Formpave delivers. To be able to offer our customers an environmental alternative that maintains our high, exacting standards is a key element in our vision for the future, along with our continued research, improvement and development." Steve Jones added.