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**Notes
1. 4Omm aggregate may be used in mass concrete or large
foundation bases.
2. S3 slump class
concrete can be used in large foundations and
should be used in trench fill foundations.
3. When concreting on steep slopes, 5Omm or in some
cases 20mm slump concrete
should be used but this will require vibrating equipment
to compact it adequately. On flat surfaces, S3
slump class concrete may be
specified if the concrete is to be compacted by hand
tamping.
4. In a few parts of the UK, local materials may not
be suitable for the production of these high strength
concretes.
In such
circumstances, Mix 8 in the
Ministry of Agriculture's Standard Costs. Part 1: Specification
should be used.
5. C35A concrete meets the
requirements of BS 8007 Code of practice for design
of concrete structures for retaining aqueous liquids
demanded by the Control of Pollution Regulations 1991.
and this concrete should be specified for any application
that is to be used for holding/storing liquids.
6. Where the concrete is subject to even occasional
de-icing salts, designated concrete PAV2 is recommended.
7. Use low consistence concrete's
for acid and abrasion resistance. Take care to
ensure full compaction of the fresh concrete and proper
curing for at least several days.
8. What used to be known as
Workability is now referred to as CONSISTENCE. New consistence
classes have been introduced as follows:
Slump Class
Target slump mm
S1
20
S2
70
S3
130
S4
180
S5
220 plus
Note: Slump is now specified and measured to the nearest
10 mm
For further reading refer to:
1. BS EN 206-1: Concrete: Specification,
performance, production and conformity.
BS 8500-1
: Method of specifying and guidance for the producer
BS 8500-2
: Specification for constituent materials and concrete
2. MINISTRY OF AGRICULTURE FISHERIES & FOOD. Standard
costs. Part 1. Specification, July 1992. London, MAFF.
3. BRITISH CEMENT ASSOCIATION. Pocket guide 1. Laying
concrete. Publication 47.518, 1983. 8pp. Crowthorne,
British Cement Association.
Smiths concrete limited does it’s
best to ensure that any advice, recommendations or information
given is accurate. However, no liability of any kind
(including liability for negligence) is accepted in
this respect by the company it’s servants or agents.
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