Specification 49 Stone Mastic Asphalt for Airfields - Ministry of Defence

Specification 49 Stone Mastic Asphalt for Airfields 5 Laid Material Requirements
5.4.2 The course thickness shall be determined:
• at minimum intervals of every * m² laid or from
every 2 h work, whichever is the more frequent;
and
• at locations agreed with the Project Manager.
Alternate cores shall be taken so that the edge of
the core hole is, at its nearest point, 25 mm to
50 mm from the lane joint. The walls and base of
all holes from which core samples have been cut
shall be filled in accordance with Clause 6.24.
* Project Manager to provide value for specific job
specification; advice given in Clause Z.4 of
Appendix Z.
5.5 IN SITU DENSITY
Every core taken as required by sub-Clause 5.4
from the area shall be tested for bulk density
according to BS EN 12697-6, Procedure A. The
rolling mean of 6 bulk density measurements from
cores shall not be less than the Job Minimum
Density as defined in sub-Clause 7.3.5. No
individual measurement shall be less than 98 % of
the Job Minimum Density.
5.6 FINISHED LEVELS
5.6.1 The finished surface levels shall conform
with the levels, profiles and contours shown on the
drawings and the finished levels of the underlying
courses are to be such that at no point will the
thickness of any overlying courses be less than the
thickness specified.
5.6.2 Where the Project Manager so directs,
deviations exceeding 6 mm from the required levels
shall be corrected by replacement with new
surfacing at not less than the specified course
thickness after removal of the appropriate thickness
of the offending area. The removal shall be carried
out in accordance with Clause 6.22.
5.7 SURFACE ACCURACY
5.7.1 The surface accuracy of the surfacing
material shall be measured as the gap between the
bottom of a 3 m long test straightedge and the
surface of the pavement when the straightedge is
placed unsupported on the surface in accordance
with Appendix B. The surface accuracy shall not
exceed 3 mm for surface course nor 10 mm for
binder course anywhere in any direction, other than
across the crown of a camber or across a drainage
channel.
5.7.2 Tests for regularity of the finished surface
shall be carried out
• at minimum intervals of twenty every * m² laid or
from every 2 h work, whichever is the more
frequent; and
• at locations agreed with the Project Manager.
Alternate tests shall be taken across lane joints.
* Project Manager to provide value for specific job
specification; advice given in Clause Z.4 of
Appendix Z.
5.7.3 Any non-complying area shall be removed
for the full width of the lane and replaced by the
Contractor, at his own expense, with material that
shall satisfy the acceptance criteria, as specified in
Clauses 6.22 and 6.23.
5.8 TEXTURE DEPTH
5.8.1 The texture depth of surface course SMA
shall be determined in accordance with
BS EN 13036-1 using ten measurements equally
spaced across a diagonal across a 50 m length of
laid surfacing. The test shall be repeated after
every 250 m of length paved.
5.8.2 The average texture depth for each 1000 m
length of paving, or for the complete length where
this is less than 1000 m, and the individual test
measurements shall be within the ranges given in
Table 5.3.
TABLE 5.3 TEXTURE DEPTH RANGES
Aggregate size 1000 m Mean Individual test
0/10 (1.1 ± 0.2) mm (1.1 ± 0.4) mm
0/6 (0.9 ± 0.2) mm (0.9 ± 0.4) mm
5.9 PARTICLE LOSS
5.9.1 The third and then every subsequent sixth
core taken as required by sub-Clause 5.4 shall be
tested for particle loss in accordance with
BS EN 12697-17 at (25 ± 2) °C other than that the
samples will not be moulded samples. The results
of the particle loss shall be submitted to the Project
Manager for research purposes.
(NOTE. The Project Manager is requested to issue
copies of particle loss results to the Construction Support
Team, DE.)
5.9.2 Testing for particle loss shall not be
required after 10 results have been compiled.
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