| TOPICS
BS
EN 13108 Family of Bituminous Mixtures- Continued
Skid
Resistance
Motto
of the Month
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Introduction
I hope you all had the Christmas that you desired, and
may I take this opportunity to wish you all a happy, healthy and
fulfilling New Year.
How easy the last of these goals may be achieved in relation to
employment in the Highways Maintenance Industry could well be governed
by which side of the industry you find yourself on.
Please do not say we are all on the same side, we are not.
If you are unable to make a distinction between those employed by
companies making profits for shareholders and those trying maintain
highway networks on behalf of the public/motorist/haulier I think your
powers of judgment are flawed, the latter sector usually being employed by Local Authority Highways
Departments.
Now I do not have a problem with this two sided system, it has been in
place for the whole of my career in highways maintenance and
construction, and I believe it has worked well.
But over the last ten years I feel the balance between the two sides
of the industry has tipped too far in favour of the commercial side of
the industry.
If this balance is not restored I can see the condition of the UK
highway network deteriorating not improving, and I believe this will
not just be due to cuts in funding.
In my opinion you cannot have those in charge of creating the profits
for commercial companies responsible
for the condition of the highway network, the two functions are basically
in opposition.
I can foresee many thousands of miles of basically sound highway
network, designed and supervised by qualified and experienced
Engineers and Technicians being allowed to fall into poor condition,
to provide the appearance that the new methods can achieve the
unachievable whilst maintaining /improving profits of the private
sector on reduced funding.
Just "flashing" over with a thin layer of surfacing to fool
SCANNER and improve your BVPI figures is not the way to do it.
This newsletter will be added to, but I thought it important to bring
the information below to people's attention as soon as possible.
BS
EN 13108 Family of Bituminous Mixtures- Continued
If you are not already aware of the following important documents, and in truth you should
be, you need to
obtain them and study them thoroughly, and I mean thoroughly. There are
elements of these Interim Advice Notes that introduce radical changes to the
nature of contracts based on these documents. These contractual
changes being in addition to the changes made in the nature of specifying
bituminous mixtures.
In my initial perusal of these "Notes" I have found some
significant "one liners" which could have a significant
effect on the working relationships between "client" and
"supplier".
But hopefully you do have a Materials Engineer or Pavement Design
Engineer who is keeping your organisation up to date on these matters.
The documents are :-
Interim Advice Note 101/07 - Revised Manual
of Contract Documents for Highway Works (MCHW)
900 Series - Specification for Road Pavements - Bituminous Bound
Materials
This document comes into effect from the 1st. of January 2008, as
does,
Interim Advice Note 102/07 - The Introduction
of BS EN Standards for Bituminous Mixtures - Site Supervision Aspects
Both these documents can be obtained in .pdf format from
the website,
www.standardsforhighways.co.uk
May I also recommend a an excellent twelve page
"guidance" document, in downloadable .pdf format, on the
introduction of the BS EN 13108
Family of Bituminous Mixtures to be found on the Bardon
Aggregate website.
It is titled, "European Standards for Asphalt - EN Harmonisation"
I still have to make the point that the "industry" still
wants to call everything "asphalt", whereas you will note
that the official documents refer to "Bituminous Bound
Materials" and "Bituminous Mixtures", which in my opinion,
and presumably that of the author, is the more correct description to include
all the distinct types of bituminous mixture.
However I regard this guidance document the most helpful that I have found to
date that has been provided by a major supplier of bituminous materials, (so you may
want to download it quite quickly, it could disappear).
I feel it necessary to draw your attention to the fact that this
document appears to have been produced by the "Technical
Department" of this company, thank you, and I hope these thanks
do not cause you embarrassment.
I feel I must remind you again that you must still decide the actual specification,
i.e. "target mixture composition" of the new bituminous
mixture description, and its properties must be validated by
"type testing".
I do not expect the supplier to do everything
for you, somebody on the "client side", hopefully a
Materials Engineer is earning his salary providing the appropriate
information.
 At
this time I am not going to go through this website changing the
description of all references to bituminous bound materials, I could
do it but I do not think the time is yet right to do it.
The terms I use, and that have been used for decades, and that do
basically denote an actual specification for a particular bituminous
mixture will be held in the minds of Engineers, and Engineering
Technicians for some time to come.
I believe at this time of transition it is best to take this knowledge
of the material you require and make a direct conversion to a
bituminous mixture description under the new BS EN standard that will
provide you with the material you are familiar with, and that has the
same engineering properties.
As time goes by, you (Engineers and Engineering technicians) will become
familiar with the materials that you are receiving under the new
descriptions, and agreed "specifications".
I may then begin
to add the new descriptions with direct conversions of the old
"recipe" specifications I was/am familiar with.
For those of you who are constant users of bituminous bound materials
I do not think this transition will be as difficult as you may fear, you will soon
get used to the new names.
The interesting bit will be deciding the "target mixture
composition" ("recipe") that you want for that
particular bituminous mixture type description, and the
"discussion" afterwards if/when any supplied material fails
to fall within the tolerances applied to the "target mixture
composition" (recipe) that you have defined.
I foresee that it could be possible for a material not to have
"failed" but to actually "comply" with a different
set of "target mixture composition" requirements, to those
that you have defined.
But if things do get difficult you can always go and ask your
"Manager" for advice and guidance on the subject, and ask
what course of action you need to take when material has
"failed" to comply with the tolerances applied to the
defined "target mixture composition" set by that authority.
I have seen this "difficulty" before with the
"specification" of thermoplastic road marking
materials.
Suppliers/contractors of supplied materials that have
"failed", i.e. not met the requirements that you have
specified from the various tables of "levels of properties",
have claimed that the thermoplastic materials have not actually "failed"
but just meet a different level of properties to the
"specification" that you required.
(You wanted a "Mondeo", but you got a "Fiesta",
for a "Mondeo" price. It still gets you around, why are you
complaining. Well okay, can I have a refund of the price difference.)
Even if you do obtain your refund this still leaves you with a
road surface, or road marking, that has properties less than you
stipulated in your design.
What I would suggest, in the real highway maintenance world, is keep a
dialogue going with your local suppliers and contractors, the people
that you work with on a daily basis, make sure that you all know what
it is you want going through the paver or into the patch.
I know this goes against "grand planning", but I believe it
is the best course of action to produce the best quality of work
within budget limits, with the least amount of problems.
I fear the worst when "Managers" (on both sides), not
experienced Engineers and Engineering Technicians, start
deciding what bituminous mixtures will be used on local highway
networks.
And finally, keep sampling and testing, I believe this is the only way
that you will be able to confirm that the new practices are providing
you with the materials you required.
But, here is one of the "one liners" I mentioned earlier
(well one and half lines actually),
Interim Advice Note 102/7 -
Chapter 5 : Site Activities - Paragraph 5.1 : General
"The specifications in the BS EN 13108 set of European
Standards only apply to the mixture at the time that it is loaded into
the delivery vehicle."
I think this is a rather "interesting" short statement, that
may possibly have considerable significance.
Skid
Resistance
On seeking out and
downloading the Interim Advice notes mentioned above I also found,
Interim Advice Note 98/07 - Guidance for HA
Service Providers on Implementing the Skid Resistance Policy (HD
28/04)
This is an important document which has been in effect
since its publication in September 2007.
"It provides specific instructions and additional guidance
about how to implement the Standard on trunk roads in England as well
as introduces several changes to the Standard itself."
Although this document is specifically for trunk roads, the
procedures and guidance contained in it are often adopted by Local
Authorities on their more highly trafficked highways within their
highway networks
I would suggest downloading and studying the document will bring you
up to date with current recommended practice.
Motto of the Month
"Give a man
a fish, you feed him for a day, teach a man to fish and you feed him for
life."
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