Download Standard Specification of Roads Works - Section 9 - Concrete PDF

TitleStandard Specification of Roads Works - Section 9 - Concrete
File Size201.6 KB
Total Pages36
Document Text Contents
Page 35

(JKR/SPJ/rev.2005)

S9-35




8.0 DIMENSIONAL DEVIATIONS

Deviations arise at three stages of construction: during initial setting out, during in-situ construction
and during erection and assembly. It is important that effective control measures are adopted by the
Contractor to ensure that deviations are kept within permissible limits.

The following permissible deviations (see BS 5606) are given as both plus and minus values on a
specific dimension.

8.1 In situ concrete


Construction Location mm
Walls Thickness

Straightness in 5m
Abrupt changes in continuous surface
Verticality up to 2m
Up to 3m
Up to 7m

± 8
± 9
± 4
11
17
16

Columns Size on plan up to 1m
Verticality up to 3m
Up to 7m
Squareness

± 8
12
16
9

Beams Depth
(Perimeter beams) up to 600mm
Over 600mm
(Internal beams) up to 600mm
Over 600mm
Level
Variation from target plane
Straightness in 6m


± 13
± 20
± 12
± 16

± 22
10

Structural slab Level
Variation from target plane
Structural soffit


± 25
± 19

Foundation Dimensions on plan ± 50

8.2 Precast concrete members


Dimension Location mm
Length Up to 3m

3m to 4.5m
4.5m to 6m
Additional deviation for every subsequent 6m

± 6
± 9
± 12
± 6

Cross section Up to 500mm
500mm to 750mm
Additional deviation for every subsequent
250mm

± 6
± 9
± 3

Straightness Up to 3m
3m to 6m
6m to 12m
Additional deviation for every subsequent 6m

6
9
12
6


8.3 Control of accuracy during construction


Checking by the Contractor shall be systematic and be undertaken at all stages of
construction. Particular attention shall be given to monitoring of construction in areas where
the work would be affected in appearance or performance.

8.3.1 Dimensional control


The Contractor shall ensure to achieve dimensional control by:

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