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Concrete is big business and its specification complex. To help those who sell and buy concrete, we’ve amended the British Standards which complement the European concrete specification. This blog post explains the changes.

BS 8500-1 and BS 8500-2 are two British Standards written to help users of BS EN 206 – the European concrete specification standard – in the UK. Both British Standards provide guidance on UK national provisions, materials, methods of testing and procedures outside the scope of the European standard, but known here.

BS 8500-1 describes the most up-to-date methods of specifying concrete – making it an essential guide for UK concrete buyers. It describes ways of specifying concrete and gives specifiers guidance. Annex A provides details on the concrete quality to be specified for selected exposure classes, intended working life and nominal cover to normal reinforcement.

The standard covers:

• Requirements for the constituents of concrete
• The properties of fresh and hardened concrete and their verification
• The limitations for concrete composition
• The specification of concrete
• The delivery of fresh concrete
• The production control procedures
• The conformity criteria and evaluation of conformity

Meanwhile BS 8500-2 provides concrete producers with essential up-to-date specifications on constituent materials and concrete. It specifies several basic requirements for concrete and its constituent materials, and gives specific requirements relating to the types of concrete listed in BS 8500-1.

This standard also specifies:

• Requirements relating to delivery
• Conformity testing
• Production control and transport as well as requirements for the constituents of concrete
• The properties of fresh and hardened concrete and their verification
• The limitations for concrete composition
• The specification of concrete, the delivery of fresh concrete, the production control procedures and the conformity criteria and evaluation of conformity.

What’s new and why

The standards have been amended because while writing new specifications for natural pozzolana for use with Portland cement in concrete (BS 8615 -1 and 2), it became evident that both parts of BS 8500 should change to reflect the increased range of cementitious materials in use.

These materials include natural pozzolana, natural calcined pozzolana or high reactivity natural calcined pozzolana as an addition, Portland�pozzolana and pozzolanic cements, as well as a range of ternary cements which include up to 20 per cent limestone fines.

Consequently, new recommendations have been added to Part 1 on the use of natural, natural calcined and high reactivity natural calcined pozzolana, as part of cement or in combination, based on the assumption that the performance in concrete will be similar to fly ash.

In addition, new recommendations for ternary cements have been added, which include up to 20 per cent limestone fines for applications where their use is considered safe and durable. As well the option to use durability modelling or an equivalent durability procedure is clarified.

Minor editorial changes have also been made, but these aren’t tagged, such as the change of nomenclature from N/mm2 to MPa for stress.

The same amendments have been carried through into Part 2. Plus, the equivalent concrete performance concept (ECPC) to demonstrate equivalence for the use of additions is clarified and additional guidance is provided on the preparation and transport of cube specimens for strength testing.

Note too that these 2018 amendments come on top of a complete revision of both the standards in 2015 which was done to align them with BS EN 206:2013. The new standards are now formally known as:

and

These standards supply comprehensive and critical information, so it’s recommended that Part 1 is used by factory production control managers and commercial technical managers working for ready mix concrete manufacturers, as well as concrete contractors and specifiers who can use the information to assist designers. Part 2 should in addition be used by concrete producers and manufacturers.

For an ancient building material, concrete – and the uses to which it can be put – still changes remarkably often. Which is why those who work with this most fundamental of building materials need to get hold of these amended standards and use them to stay at the leading edge of what’s possible.