Technical Standards

Please note that all technical information is provided for information purposes only and it is explicitly the responsibility of the client to ensure that they order the correct product that is fit for purpose.

Ready Mixed Concrete Standards

Concrete BS EN 206-1 Specification, performance, production and conformity
BS 8500-1 Method of specifying and guidance for the supplier
BS 8500-2 Specification for constituent materials and concrete

Selection of Consistence
The consistence of fresh concrete should be suitable for the conditions of handling and placing so that after compaction, concrete surrounds all reinforcement, tendons and ducts and completely fills any formwork. The table below is extracted from BS 8500-1 and provides guidance on consistence expressed as slump class appropriate to different uses. Where concrete is laid on a slope, a lower slump class than that given in the table may be necessary.

Consistence suitable for different uses of in-situ concrete
Use of concrete Type of compaction Consistence Class
Kerb bedding and backing Tamping S1
Floors and hand place pavements Poker or beam vibration S2
Strip footings Poker or beam vibration S3
Mass concrete foundations Poker or beam vibration and or tamping S3
Blinding Poker or beam vibration and or tamping S3
Normal reinforced concrete in slabs, beams, walls and columns Poker or beam vibration and or tamping S3
Sliding formwork construction Poker or beam vibration and or tamping S2
Pumped concrete Poker or beam vibration and or tamping S3
Trench Fill Self compacting S4
In-situ piling Self compacting S4

Summary of Requirements for Designated Concretes

Concrete Designation MinimumStrengthClass DefaultSlumpClass Maximumw/c ratio Minimum Cement Content based on4/20mm Aggregate CementType Supplied
GEN0 C6/8 S3 120 CEM 1, CEM 11b-v+sr
GEN1 C8/10 S3 180 CEM 1, CEM 11b-v+sr
GEN2 C12/15 S3 200 CEM 1, CEM 11b-v+sr
GEN3 C16/20 S3 220 CEM 1, CEM 11b-v+sr
RC20/25 C20/25 S3 0.70 240 CEM 1, CEM 11b-v+sr
RC25/30 C25/30 S3 0.65 260 CEM 1, CEM 11b-v+sr  b
RC28/35 C28/35 S3 0.60 280 CEM 1, CEM 11b-v+sr  b
RC30/37 C30/37 S3 0.55 300 CEM 1, CEM 11b-v+sr  b
RC32/40 C32/40 S3 0.55 300 CEM 1, CEM 11b-v+sr  b
RC35/45 C35/45 S3 0.50 320 CEM 1, CEM 11b-v+sr  b
RC40/50 C40/50 S3 0.45 340 CEM 1, CEM 11b-v+sr  b
RC40/50XF C40/50 S3 0.45 340 CEM 1, CEM 11b-v+sr
PAV1 C25/30 c S2 0.60 280 CEM 1, CEM 11b-v+sr
PAV2 C32/40 c S3 0.45 340 CEM 1, CEM 11b-v+sr
FND2 C25/30 S3 0.550.50 320340 CEM 11b-v+srCEM 1
FND2Z C25/30 S3 0.55 320 CEM 1, CEM 11b-v+sr
FND3 C25/30 S3 0.40 380 CEM 11b-v+sr
FND3Z C25/30 S3 0.50 340 CEM 1, CEM 11b-v+sr
FND4Z C25/30 S3 0.45 360 CEM 1, CEM 11b-v+sr

a)      See BS 8500-2 Clause 6 for full requirements of designated concretes

b)      Only if specifically permitted under BS 8500-2 clause 4.2.3

c)      The concrete shall contain air-entraining admixture to give a minimum air content by volume of 4.5% with 20mm aggregate and 6.5% with 10mm aggregate at delivery.

Guidance on the selection of designated concrete and standardised prescribed concrete in housing and other applications

Application Designated Concrete StandardisedPrescribed Concrete Recommended Consistence Class
Unreinforced concrete foundations and associated works requiring DC-1 Concrete  
Blinding and mass concrete fill GEN 1 ST2 S3 c
Strip footings GEN 1 ST2 S3 c
Mass concrete foundations GEN 1 ST2 S3
Trench fill foundations GEN 1 ST2 S4
Drainage works to give immediate support GEN 1 ST2 S1
Other drainage works GEN 1 ST2 S3 c
Oversite below suspended slabs GEN 1 ST2 S3 c
Unreinforced foundations requiring DC-2 to DC-4 Concrete
DC-2 FND2 N/A S3 c,d
DC-2z FND2Z N/A S3 c,d
DC-3 FND3 N/A S3 c,d
DC-3z FND3Z N/A S3 c,d
DC-4 FND4 N/A S3 c,d
DC-4z FND4Z N/A S3 c,d
DC-4m FND 4M N/A S3 c,d
General applications
Kerb bedding and backing Gen 0 ST1 S1
House floors with no embedded metal
Permanent finish to be added, e.g. a screed or floating floor Gen1 ST2 S2
No permanent finish to be added, e.g. carpeted Gen2 ST3 S2
Garage floors with no embedded metal Gen3 ST4 S2
Wearing surface: light foot and trolley traffic RC 25/30 ST4 S2
Wearing surface: general industrial RC32/40 N/A S2
Wearing surface: heavy industrial e RC40/50 N/A S2
House drives and domestic parking PAV1 N/A S2 c
Heavy-duty external paving with rubber tyred vehicles e PAV2 N/A S3 c,f

a)      Concrete containing embedded metal should be treated as reinforced
b)      Reference should be made to Table A3 BS8500-1 for designated concretes for reinforced foundations and reinforced concrete
c)      This is the default slump class for this designated concrete
d)      For trench fill, the recommended consistence class is S4
e)      For extreme applications, e.g. foundry floors and busy public roads, specialist advice should be sought
f)       Depends on the method of placing and finishing

Hillhouse Group

Hillhouse Group