AVs in Mastic Asphalt
Is Air Void testing of HRA as stated within the SROH only applicable to the conventional family of HRA’s as stated within the SROH on page 97 which says as follows: “A2.1.1 Surface Course Mixtures The following HRA surface course mixture options are permitted….. (3) Footways, Footpaths and Cycle Tracks HRA surface course mixture shall be HRA 15/10F surf 100/150 rec or, HRA 15/10F surf 70/100 rec or HRA 15/10F surf 40/60 rec….” If we are required to use a “sand carpet” type of fine aggregate material (as is permitted within S8.3.3. and/or S8.3.4 of the SROH) then ,according to the information on the materials collection tickets, the material we are using is titled as either HRA 0/2F for 2mm aggregate, or, if we requested 4mm aggregate, it would then become HRA0/4F Neither of the above fit anywhere within the SROH footway definition of a HRA which leads me to believe that sand carpet, although a form of HRA, falls under the “any other bituminous materials within the specification” which, as per the Air Void table on page 77 means that there is guidance within the SROH on compaction but no air void limits apply. Can you confirm that the fine asphalt footway reinstatement material commonly known as “sand carpet” is actually a material that can have the relevant air void test applied to it?
Compaction Adjacent to Structures [particularly Poles]
There are circumstances where Openreach carry out small excavations (e.g. pole testing). A number of HAs have demanded that the dimensions of such excavations should be expanded such that mechanical compaction equipment can fit into the space available. Whilst recognising that all excavations need to be compacted correctly, Openreach would argue that hand compaction is acceptable. We would request a statement in the SRoH covering these circumstances
Coring of Fillets [Areas of reinstatement in close proximity to Apparatus
Openreach have been presented with invoices for cores taken close to surface apparatus such that it would be impossible to take a fillet in accordance with current SRoH requirements, given the flanges which surround said apparatus. We would like a definitive statement in the SRoH which defined what (if any) tests are appropriate in such circumstances.
Bound Layers in reinstatements within extended trim-lines failing Air Voids
Cores fail for air voids where the core has been taken in the trim back area around a utility reinstatement, are we required to dig out the existing HA backfill and replace it in compacted layers?
Depth of Bound Layers in reinstatements within extended trim-lines
Cores fail for overall depth after being taken in the trimmed back area around our reinstatement, in these cases the trim back is full depth down to the existing HA backfill material, are we required to dig out the HA sub base material to a depth suitable for the SROH ?
Depth of Surface Course in reinstatements within extended trim-lines
Cores that are being taken in trimmed back areas around our reinstatements are failing for lack of surface course depth where the utility has reinstated on top of the existing HA binder course.
Exemption from Coring (less than 200mm)
It is my understanding that as per S10.2.3 2) all bituminous materials must be compacted and comply with the S10.1. Restriction for core extraction in air voids section, S10.2.3 4) “with no part of any core being within 100 mm of any surface apparatus within the reinstatement.” Under Notes for guidance this is explained as NG10.2.3 5) “When taking cores near surface apparatus, Section S10.2.3(4) requires a minimum clearance of 100mm to avoid damaging the apparatus or structure it is bedded on. However it is possible that some surface apparatus may have wider than normal flanges and there may be instances where a greater clearance is required to avoid damage. If doubt exists, liaison with the owner of the apparatus should be undertaken in advance.” Within the adopted highway there are a number of surface apparatuses where the undertaker has consistently changed their working practice to reduce the size of the excavation so there is no part greater than 200mm from the apparatus. Stopping us from fitting a 100mm core more than 100mm from the apparatus. As highways authority we are concerned that the undertaker could not compact the material in the correct material lifts. The undertaker is claiming it can’t be tested as per the above comment in S10.2.3 4) and minimum trimback from S188.8.131.52 don’t apply as it is not a carriageway. Example: The works: Installation of a water meter, the surface apparatus is an Atplas Box. Solution: I would like to core within the trimback. This would be a full 100mm core but would be within the 100mm of the surface apparatus. There is absolutely no risk of damage to the apparatus as the core will be beyond the apparatus and its supports. As above, if we as the authority extract a core within 100mm of a surface apparatus and cause no damage to the apparatus and we send the core for air void testing and it fails to table S10.1. Are we correct to issue a defect for air voids using this result as valid failure?
We have been using Ironguard (a proprietary flowable mastic asphalt) very successfully in several Highway Authority areas to reinstate around ironwork in the carriageway, especially on S81 work. The product is HAPAS approved, and in our views is permitted under the SROH. We have one Highway Authority who has said the product cannot be used under the SROH. We understand the same Highway Authority permits its own contractor to use the product in their area.
It would be appreciated if your group could review this and confirm that this product can be used in the carriageway to reinstate around ironworks.
Our supplier of frames and covers are advising us to use a flowable concrete binder course which is HAPAS approved up to 60mm from the road surface and acceptable under the Design Manual for Roads and Bridges HA104/09. On top of this the matching surface course to the existing road can be used.
We wish to follow this specification however some Highway Authorities are claiming this is unacceptable under the SROH and 100mm of flexible surface course & binder course is required. I understand that under S184.108.40.206 bedding material, including C32/40 strength concrete can fill the excavation to within 100mm of the road surface but the flowable concrete we are using is not “bedding material”.
Attached to this email are the data sheets for the material we are wishing to use and would be grateful if the SROH Working Group can clarify if material is acceptable (Ultracrete QC10) bearing in mind the quote from S11.5.1 “Works undertaken to apparatus shall be to the standard and specification of the owner of the apparatus”.
A Highway Authority has issued an Undertaker with a number of Defect Notices, stating non-compliance in respect of compaction of unbound materials. The HA contends that the unbound material is insufficiently compacted on the basis of results from Panda Penetrometer compaction testing results, carried out following core extraction. In part, the HA is quoting recent field-based trials/research which used the same Panda Penetrometer testing to check CBR measurements, and thereby classified the unbound layers as achieving CBRs of 30% as the pass or fail threshold.
Does the current SROH 3rd Edition support retrospective end-product testing of unbound materials as determining compliance?
If a utility worked at a time that the SROH 1st Edition was in force, when Air Voids were not part of the specification, then if a HA subsequently chooses to core this reinstatement, can they legitimately fail the reinstatement for air void specification outlined in SROH 2nd Edition?