1. Londonwide Asphalt Specification An 2016 update
Ian D Walsh
Senior Consultant
Road Consultants

3. What’s New ! The changes are relatively small but not unimportant
The principal changes to the document are as a result of
Effect of the Construction Products Regulations on UK documentation
amendments to the underpinning British Standards
BS :2015
PD 6691 :2015
Specification for Highway Works
Interim Advice Notes
latest guidance notes from others
ADEPT and RSTA
feedback from some users.
Provision of improved guidance on maintenace options

4. CPR effects
The CPR is a legal entity now compulsory for all construction products placed on the market
It is implemented via European Standards brought into UK via a British Standard
E.g BS EN – Asphalt Concrete
The standard contains everything necessary for placing on the market and stated on the CE Marking Certificate
CE Marking Certificates are available on all manufacturers’ websites
Nothing extra can be added to the Certificated properties on a national basis but maybe on a local specification
This includes additional Quality Assurance
All national requirements i.e. SHW changes including IAN’s have to be approved by EU in Brussels to ensure they do not generate a barrier to trade
This is a very slow bureaucratic process

5. CPR and Thin Surfacing [Clause 942]
The SHW made HAPAS certification mandatory
IAN 157 had to change this to enable other providers
Only BBA provide this service currently
Cl 942 material is almost always a sub set of SMA to BS EN which is covered by CE Marking
The HAPAS scheme has been amended to concentrate more on installation
Currently there is no SHW Clause for SMA surface course BUT
These are normally proprietary products from your usual supplier
They manufactured to the EN and installed to NHSS AND
SMA may be specified in Appendix 7/1 using a reference to PD Annex 5 and the performance parameters required for the site:
Texture Depth (max and min) [IAN 156], PSV [IAN 154] Wheel Track Rate [PD 6691 Table D.2]. Crack resistance [BS EN ]

6. Other HAPAS Schemes
It applies to products that have no EN Standard and to Installation - not covered by CE Marking
High Friction Surfacing [HFS]
ADEPT RSTA Guidelines on installation
Document advice on traffic speeds
For most urban streets HFS is not necessary
Relationship between very slow speed traffic and PSV
LOTAMB Skid Policy
IL vs 0.50 ?
BBA research on service life
A good foundation is essential
Material laid in cold weather has shorter life
Thermosetting has better life than thermoplastic
HFS has the life shown on the Certificates

7. BBA HFS Study conclusions

8. Other BBA HAPAS Certificates
Bridge Deck Waterproofing to BD47 (9 products)
It may not apply to overlays less than 120mm
IAN96 Rev 1 gives required minimun bond strengths
Permanent Cold Surfacing Materials (4 products)
Patching materials ( 7 products)
Thermal repairs ( 1 product)
Overseal and Inlay crack sealants( 13products)
To be flexible, rut and skid resistant

9. Asphalt Changes - PD 6691:2015 [1]
Deformation resistance
A NOTE has been added stating ‘for very slow moving or stationary traffic in bus lanes, bus stops, major stop lines, docks and airport taxiways and stands an even better deformation is required’ than WTR2
NB The test method is now a EN so values are different
BS has been withdrawn
For materials with a HAPAS Certification half the values for WTR2 in PD ( as before) and a PMB specified
Quality Assurance
NHSS 14 scheme will be withdrawn this year and the requirements incorporated in a further revised PD 6691
A new BS EN ISO 9001: 2015 (published in September 2015) has extensive revisions
It will take until October 2016 for all the NHSS scheme documentation to be updated e.g. NHSS 7, 12, 16, 23, 30.
Clients may receive Certificates with the new date or with the old date. The latter remain valid until September 2018

10. Asphalt Changes - PD 6691:2015 [2]
Materials changes
Recycled Asphalt (RA) – there is recognition that the use of softening point as well as penetration may be beneficial where the binder from RA is modified. Reference to guidelines regarding Water Sensitivity has been removed.
Hot Rolled Asphalt – Revised wording in clause covering HRA which now clearly states “All mixtures are recipe unless they are designed”
Asphalt Concrete Table B.2 Binder grades – 70/100 has been added to the recommended grades of bitumen for both design base and binder course mixtures.
Béton Bitumineux pour chaussées Aéronautiques (BBA ) added
A fine graded rich AC
Intended for airfields only

11. Asphalt Changes – BS
Bond Coats - New text has been added which recommends a lower minimum rate of application of 0.2kg/m2 for the application of the bond coat to a newly laid asphalt substratum as against kg/m2 for planed, milled, or existing surfaces
Compacted thickness - The tables detailing the compacted thicknesses have been moved and now immediately follow Clause 5.4. To improve clarity and understanding, the column headings for nominal layer thickness now state “Nominal target layer thickness”. There has been a new note added to Table 1B for HRA which advises that Type C 35/14 and Type F 35/14 may also be laid at a nominal target thickness of 45mm with a minimum compacted thickness at any point of 40mm.
Adverse weather - Text has been added to emphasis the effects of “Wind chill” on laying chipped HRA.
Surface course joints – There is now specific acceptance of the use of edge compactors during the laying process. ( This is highly recommended to reduce the failure rate of joints in thin surface courses )
Chipping HRA spec has been removed 70% shoulder to shoulder should continue to be specified in Appendix 7/1 together with the minimum and maximum texture depth
S4H HRA 55/10F surf 40/60 des PSV 60* has been added to the schedule

12. Aide for compilers of Appendix 7/1 IAN 155/12

13. Surface Dressing RN 39 [March 2016]
Principal Change
Dressing now referenced with a Code letter S, R, D
PSV for less heavily trafficked roads
March 2016

14. Unchanged useful text Maintenance for surface defects
General, Cracking, Rutting, Fretting and potholing, Longitudinal Profile, Skid Resistance and Texture depth
>>>
Guidance on bus lane surfacing
Asphalt, pavers, grouted macadam, concrete ,
Updated ADEPT Guidance on Tar
Update on references not to text
Responsibility lies with Client to identify tar with a PAKmarker on cores

16. On the horizon - May-ish
TA 81/16 Coloured Surfacing in Road Layout (Excluding Traffic Calming)
HD 39/16 Footway and cycleway design
HD 28 /16 Skidding resistance
New SHW Series Asphalt materials
Includes Stone Mastic Asphalt Surface Course (TS2010) for Scotland and other minor changes
New 923 Cold Applied Ultra Thin Surfacing
Some revisions to Cl 942
New SHW Series 800 Sub base and HBM – [Spring 2016]
Revision to HD 25 ( IAN 73) Draft available end of May [2017]
Revision to HD 26 to incorporate new HBM terminology [2016/7]
Revision of BS 7533 series for design and installation of paving [2016/17]