Introduction:

British Standard BS 8500-1 , the standard which covers concrete specification, identifies a number of mixes which are 'designated' a simple(ish) name, with each mix intended for a range of specific purposes within the civil engineering industry.

The idea behind designated mixes is to simplify the specification process, primarily by limiting customer input to selecting strength, aggregate size and consistence (although there can be some additional input, such as cement type , in certain circumstances). The producer then creates a concrete to meet these requirements and retains control over other factors as they see best for any praticular location and application.

Only accredited producers can supply designated mixes, whereas any producer can supply a prescribed mix , because prescribed mixes are particular recipes rather than mixes produced locally and intended to reach certain strength and perfomance parameters. Accreditation is undertaken by approved third parties, the most common being the Quality Scheme for Ready Mix Concrete (QSRMC), although there are others.

qsrmc

For the vast majority of paving, hard-landscaping and drainage projects, a designated concrete is easier to specify than going to all the trouble of creating a prescribed or standardized prescribed concrete.


 Designated mixes available

Designation Applications Types Strengths
GEN General civil engineering applications GEN 0
GEN 1
GEN 2
GEN 3
Typically ranging C6/8 up to C16/20
FND Foundations including reinforced foundations FND 2
FND 3
FND 4
Typically C25/30
PAV Driveways and Paving PAV 1
PAV 2
C28/35 and C32/40
RC Reinforced concrete floor slabs RC30
to
RC 50
C25/30 to C40/50

 Typical applications for designated mixes

Use Mix Consistence
Kerbs and edgings bed and haunching GEN 0 S1
Drainage works needing immediate support GEN 1 S1
General drainage works GEN 1 S3
Residential driveways, domestic and external parking PAV 1 S2
Heavy-duty commercial external paving PAV 2 S2
Blinding and mass concrete fill GEN 1 S3
Strip footings GEN 1 S3
House floor with no steel reinforcement, where permanent finish is to be added e.g. a screed GEN 1 S2
House floor with no steel reinforcement, with no permanent finish e.g. carpeted GEN 2 S2
Garage/shed floor with no steel reinforcement GEN 3 S2