Concrete Sector Sustainability Working Group (CSSWG)

Concrete is a locally produced material that supports local employment and the fabric of our society.

 

The use of exposed concrete to maximise thermal mass allows us to use natural environmental systems to cool and heat our built environment. In naturally ventilated concrete buildings, the provision of openable windows can provide good airflow and a degree of occupant control, which has a positive effect on the occupants 'comfort'. The exposed concrete used in naturally ventilated buildings can reflect light far into a building's interior. This can reduce the need for artificial lighting, improving the quality of light for the occupants and helping to prevent eye strain.

 

Furthermore, as concrete is naturally inorganic and inert it does not need treatment with additional toxic chemical treatments, such as the Volatile Organic Compounds (VOCs) used to preserve timber. The bonus of concrete is that, when used in naturally ventilated buildings, it provides a healthier indoor air quality and can help to reduce the incidence of sick-building syndrome in commercial buildings. Physical proof of concrete's inherent neutrality is its use in the London ring-main a vast engineering undertaking, twice as long as the Channel Tunnel, which supplies 50% of the capital's water supply.

 

The Government is committed to developing 'sustainable communities' which have been defined as:

 

"Places where people want to live and work, now and in the future. They meet the diverse needs of existing and future residents, are sensitive to their environment and contribute to a high quality of life. They are safe and inclusive, well planned, built and run and offer equality of opportunity and good services for all."

 

There are many ways in which concrete products can contribute positively to these aims. Concrete offers a range of 'value-added' benefits that are inherent properties of the material and come at no extra cost.

 

Benefits such as: inherent fire resistance, acoustic performance, strength, robustness and durability, which last throughout the life of the structure.

 

The full structural capacity of a masonry or concrete wall, with its considerable reserve of strength and ability to accommodate future changes, far exceeds design requirements. It is this inherent robustness that has enabled traditionally built houses to cater for increased loads emanating from alterations and adaptation.

 

Their strength also facilitates the introduction of concrete upper floors which provide clear spans between external walls and will support internal masonry walls. All internal walls below become non-load bearing, producing a design where the layout can be altered to cater for future changes in living requirements, so satisfying the government's requirement for 'lifetime homes'. Design codes, Government documents and other standards such as those issued by the Highways Agency give clear and effective requirements and guidance on the robustness of structures, i.e. ensuring that structures will not succumb to progressive collapse if one part becomes compromised. This benefit is understandably important: people need to be able to rely on the design of a structure to maintain its robustness even, to a reasonable degree, during extreme events. Concrete structures are particularly robust the reinforcement ensures that alternative load paths are utilised in the event of a problem. The effectiveness of the continuity in concrete structures is unsurpassed.

 

Rising crime is causing increasing concern about personal safety, not only in relation to crime on the streets but also intrusions into our buildings. Security has been improved by way of locks and alarm systems to windows and doors, but what of the structure itself?

Concrete and masonry walls are accepted as being solid and robust and this benefit should not be underestimated. But it cannot be assumed that all other forms of construction offer the same degree of robustness and security. The implication of the term 'Robust Detail' is that all forms of construction meeting this requirement are physically robust, but this is not necessarily true. They are only robust in terms of reliably meeting the sound insulation requirements (as in the Building Regulations Part E). The term does not relate to robustness in a wider sense e.g. structural robustness or impact resistance. For example, the Robust Details for acoustic properties of separating walls require two strong 100mm tied leaves of masonry. On the other hand, alternative methods of construction for party walls use a much more lightweight form of construction, which is reduced still further within the roof space.

In light of climate change predictions it is also important that we consider the security of our built environment to debris penetrating the built fabric during storm events. Research conducted by the Texas Tech University's Wind Engineering Research Center concluded that an exterior concrete wall is one of the premier systems for ensuring safety for homeowners from debris carried by tornado- and hurricane-force winds. University researchers conducted a series of analytical and physical tests of numerous exterior wall systems for residential housing, subjecting them to projectiles driven by the severest of winds. Only concrete wall systems were proven to withstand 100% of all known hurricane-force winds, and over 99% of tornado-force winds.

 

The use of SUDS paving, by Marshalls, at housing estate in Oxford.

Further information

• Transport
• Local community