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Coring
of Completed Reinstatements - The Picture in Devon - Source
Devon County Council
To determine the
overall level of compliance by Utilities to the nationally
agreed reinstatement specification a Countywide coring
programme has been undertaken in Devon County Council.
In total 235 cores were taken of carriageway and footway
permanent reinstatements from which an analysis was made of
the following:
(1) total
depth of bituminous material found at each coring location
compared to the specified requirement;
(2) the
quality of materials, standard of workmanship and degree of
compaction.
The initial
comparison of overall depths revealed a compliance of 63%,
but when account was taken of quality of workmanship,
materials etc., the overall compliance fell to 41%.
Total Cores = 235 Total Cores
= 235
No. complied = 148 No.
complied = 97
% complied = 63% % complied =
41%
Apart from deficiencies in
the overall depth of bituminous material other deficiencies
were identified. The most significant of which were:
soft unstable material;
poorly compacted material;
no sealant applied to the
edges of reinstatements.
All the above
defects have the effect of reducing the durability of the
material used thereby reducing the service life of the
reinstatement. An analysis of individual Utilities
performance revealed significant differences in compliance
both in relation to overall depth of material and general
compliance. For the purpose of the analysis it was
considered inappropriate to use a small sample size and
therefore performance has only been compared between those
Utilities where more than ten cores were taken of their
reinstatements. In respect of total depth of material,
compliance varied from 72% to 49%. The overall level of
compliance when workmanship and quality of materials was
taken into account varied from 44% to 30%.
Further
Action
The results
of coring of reinstatements undertaken by Utilities reveals
unsatisfactory performance on their part. To protect the
highway infrastructure by ensuring Utilities compliance in
respect of workmanship and use of approved materials and to
ensure works are properly signed and guarded, the County
Council will need to continue carrying out regular
inspections of ongoing and completed works. In view of the
details revealed as a result of the coring programme, it is
proposed to undertake an annual coring programme as a
positive means of auditing Utilities' performance.
It may be
considered appropriate for representatives of the Utilities
to be asked to attend a future meeting of this Committee to
explain what measures they have or are likely to implement
to effect an improvement on their current performance.
General
It will be the responsibility
of the body initiating the coring activity to ensure that
all relevant legislation is complied with
Reinstatement
of test holes
The reinstatement of test
holes shall be in accordance with the HAUC publication
'Specification for the Reinstatement of Openings in
Highways'.
Investigatory inspection sites
shall be selected from random samples.
- The number of selected
sites should be proportional to the level of
undertaker's activity subject to a review of
performance.
- Where the purpose of the
investigatory works is to assess and determine the
current performance trends, core samples should be taken
within 6 months of completion of permanent
reinstatement.
- Where the purpose of the
investigatory works is to ascertain whether an
undertaker has complied with his duties under the New
Roads and Street Works Act 1991, core samples may be
taken by the Street Authority and/or the Undertaker, as
appear to them to be necessary.
Advance
Notice of Coring Programme
The Highway Authority and
Statutory Undertakers should advice of each phase of their
respective joint coring programme, at least 7 days prior to
commencing work.
Investigatory
Works carried out by the Highway Authority
- The Statutory Undertaker
should be invited to monitor Investigatory Works.
- All core samples should be
assessed and classified as follows:
- Technical Compliance:
where the reinstatement meets the requirements of the
HAUC specification;
- Technical Non-compliance:
where a reinstatement does not meet all the requirements
of the HAUC specification and subject to agreement,
remedial works may not be necessary; and
- Defects: where a technical
non-complying reinstatement would warrant remedial works
The defective reinstatement
procedures shall apply to 3 above.
In the event of a technical
non-complying reinstatement (given above), all reasonable
costs should be recharged to the Utility.
Investigatory
Works Carried Out by Statutory Undertaker
- The Highway Authority
should be invited to monitor Investigatory Works.
- The defective
reinstatement procedures, as it applies to time scales
and corrective measures, shall apply to non-complying
reinstatements identified by core sampling. However,
defective reinstatement charges will not apply under
these circumstances.
Statutory
Undertakers' Quality Assurance Testing
Statutory Undertakers may carry
out Quality Assurance Testing in addition to the above,
where appropriate.
The investigatory works may
be undertaken by either the Highway Authority or Statutory
Undertaker, or their appointed/nominated representative.
- Sample material should be
tested for compliance with the relevant British or
European Standard appropriate for the material and the
"Specification for the Reinstatement of Openings in
Highways".
- Analytical testing of
materials should be undertaken by a NAMAS accredited
Laboratory, approved to undertake such tests in
accordance with the procedures of the relevant British
or European Standards.
- The advice of an approved
NAMAS accredited laboratory may be sought in the event
of a dispute or doubt over material specification and
compliance, and reinstatement performance.
- Linear measurement of a
core sample shall be exempt from ii) and iii) above.
- The HAUC Conciliation and
Arbitration Procedure may be initiated in the event of
failure to agree.
Note:
All remedial works undertaken, as a consequence of
non-complying reinstatement identified by core sampling,
shall be subject to the notification requirements of the New
Roads and Street Works Act 1991 and completed within the
time scales set.
PERFORMANCE
REQUIREMENTS
For core samples less than 100mm in diameter:
- Overall thickness of
surfacing material
- Individual thickness of
surfacing material
The following may be
determined by mutual agreement:
- Correct material
- Compaction of surfacing
material
For core samples more than
100mm in diameter:
- Overall thickness of
surfacing material
- Individual thickness of
surfacing material
- Correct material, by
laboratory test
- Constituent materials
determined by laboratory test.
The following may be
determined by mutual agreement:
Compaction of surfacing
material
Notes:
- The Laboratory appointed
to undertake testing may require additional cores in
order to satisfy and comply with minimal sample size for
analytical purposes.
- Analytical tests shall
include: binder content; aggregate grading and
identification (i.e. limestone/gritstone/granite etc.).
If the material source is known, then it is likely that
the aggregate PSV values will also be known (applicable
to permanent and interim wearing course only).
FREQUENCY AND
SITING OF TEST HOLES
- Minimum of 1No. core
sample per 20 sq. metres or part thereof; or
- Minimum of 1No. core
sample per 100 metre lengths or part thereof.
- Where a non-complying
sample has been identified, additional core samples may
be taken in order to determine extent of non-compliance,
if necessary.
- The position of each core
sample shall be agreed on site.
CORE SAMPLE
RETENTION PERIOD
Highway Authority and
Statutory Undertaker to be offered the opportunity of
viewing the cores on or after the presentation of the
results.
Non-complying core samples
shall be retained until remedial works have been completed
in accordance with the reinstatement specification.
Permanent
Cold lay Surfacing Materials (PCSM's)
Where core samples are taken
from the reinstatement containing PCSM's, the Undertaker
shall provide the Highway Authority with the relevant HAUC
Certificates of Approval.
REPORT
FORMAT
Click
here to view a sample report form
REPORTING
PROCEDURES
Full report of each core
sample taken shall be copied, within one month, to the
Highway Authority or Statutory Undertaker respectively.
A summary report of results
should be presented at regional HAUC quarterly meetings by
the relevant Highway Authority. |
