| TOPICS
Reinstatement of Openings in Highways
The Beginning
of the End to "Partnering" ?
Price Fixing
in the Construction Industry
Use of the Internet
Winter Maintenance 2009-10
BS EN 12591:2009
(Added 16-11-09)
Motto
of the Month
|
Introduction
It is just three years since I retired, and I really do not
know where the time has gone. I am afraid that time is like that, it
just goes, or does it? Is the past still there to be re-visited by some
complex new technology yet to be devised.
I make this strange comment because I have recently purchased a
negative scanner, and "I are be mostly scanning negatives" in
my spare time over the last couple of months.
Since I have several thousand 35mm. negatives dating back to my
schooldays it is sometimes like visiting a time gone bye when the
images appear from the scan, when the actual photographs have long
been lost or forgotten.
In some cases I was at family functions taking photographs that I
cannot remember taking, but these were occasions from my youth when I
had more important things to remember.
I have never thrown away any good quality negatives although the
method of storage, a shoe box, does not mean they have not always been
efficiently catalogued. I exaggerate a little, some of my early
negatives are nicely stored in suitably labelled negative files.
But a large number of more recent negatives were removed from the
photograph envelopes and placed in one known place for safe keeping,
i.e. the shoe box. So I have a considerable amount more cataloguing
and filing to do as I scan.
A good many of these negatives are of work situations spanning the
whole of my career, and it is good to have reaffirmed the images I
hold in my mind, of places and situations that have been instrumental
in building my knowledge and experience.
The images from the scanned negatives are of a much better quality
than the scans I have taken of a photograph from the negative, in
effect cutting out the middle man. So hopefully I will start to
replace some of the images on my website with images of a much better
quality.
Also taking into account that I am now working the website to a 1024 x
768 pixel resolution, not the 800 x 600 that I originally used, I
would like to think that you will see some improvement in the quality
of images used on the various pages of the website. It will not be
immediate but will take place slowly as I work on updates and
additions to existing pages, but I am trying not to add any more pages
as I think there are already enough.
I just wish people would take more time to read all the information on
the various pages relating to their particular need, rather than
obtaining a little bit of information and then dropping me an email
expecting me to provide them with the information they require. I may
be being unfair as many readers may be finding the information they
require without recourse to emailing me, I would like to think so.
I do try to help the ones who come with a genuine
approach, some do not, but even then I will tell them where to look for the
information rather than just provide it.
I always like my jottings to convey a meaning, and the meaning to this
introduction is never throw away good information/records, you never
know when it will be useful.
Yes it is possible to "read" a great deal from a trial hole and
appropriate testing if you know how to "read" a road pavement profile
and the test results. However good records on actual materials, dates
used, supplier and contractor can be very useful when assessing the
performance of a road pavement many years later.
In this day of information technology and data storage, I am
surprised at how little "real" information on road pavement materials,
especially bituminous surfacing materials, is actually, accurately,
collected and collated.
If it were, or perhaps it has been but not published, we should be able to determine
which materials have been successful and which have not.
"Pieces of
paper" that cover a multitude of bituminous mixtures will not allow
you to determine which actual bituminous mixtures/recipes/designs have been successful
and which have not.
This storage and retrieval of real information should mean that you
can support the suppliers and contractors who have provided you with the
most successful surfacing, or other product or service.
But do take note that one example of success does not make the whole
company product list successful.
Reinstatement of Openings in Highways
There is now available for
download a number of documents relating to the 3rd. revision of the,
Specification for the Reinstatement of Openings
in Highways.
All these documents can be downloaded in .pdf format from the
government website,
www.dft.gov.uk/consultations/open/openingsinhighways
One of the documents is a complete
copy of the proposed revised 3rd. edition, i.e. before any further
amendments that may be introduced as a result of this consultation
exercise.
As poor quality reinstatement to openings in highways by the many and
various utility companies is one of the major cause of fail in highway
pavements, especially a prime cause/source of potholes I would suggest
that you take a serious interest in this document and the consultation
process.
I do wonder how many of those who look at the proposed 3rd. edition
will understand much of the content relating to materials that are now
able to be used in trench reinstatement, and if you think I am going
to start explaining it to you I am not.
But
you may like to read up on Alternative Reinstatement Materials in
Appendix 9, especially the section on Hydraulically Bound Mixtures,
there seems to be an awful lot of appropriate specifying to ensure the
quality of this varied material. How many of you have been on site in
a "real" trench reinstating situation.
If I were still involved in the industry I would explore the
possibility of making the supplier of the hydraulic binder responsible
for supervising its use. They obviously want to sell their product, so
they will want to see it used correctly, or time will soon show that
it is not producing the stated engineering requirements and hence
the claimed environmental benefits.
If you do not understand this document yourselves
I expect you to consult appropriate people, i.e. an experienced
Materials Engineer, if you can find one.
But it has to be said, and it has been said over and over again,
probably the biggest cause of failure of a trench reinstatement is
poor compaction in the lower layers.
It is sad to say that without correct supervision, or penalties that
actually hurt, the poor quality of reinstatements in highways will
continue to take place whatever the proposed specification will
contain.
And when I say penalties, I do not only mean penalties for the poor
quality workmanship but also penalties for the poor response to
notification of defects.
I stand to be corrected on this issue, as "Street Works", apart from
the materials side of it, was not my area of knowledge.
But I do
believe that a dangerous pothole that results from a poor
reinstatement by a utility company cannot be left unrectifeid by a local
authority once reported by a member of the public or noted in a
routine highway inspection survey, as they have "a duty of care" to
the highway using public.
I am not aware that the utility company has such a duty in relation to
highway reinstatements, but as I said this is not my area of
knowledge, and it is getting a bit "legal" so I am prepared to be
corrected.
However if the utility companies do have such a duty it
seems to be going unimplemented in the area that I live, where the
local authority seems to be the body that makes such potholes safe.
Thus in a number of ways poor quality reinstatements to opening in
highways causes a heavy drain on highway maintenance budgets by having
to at least make subsequent potholes safe if not a full repair.
This
is apart from the general deterioration in the surrounding area of
highway pavement that often occurs as a result of a severe disturbance
in the matrix of the highway.
The reinstatement of openings in highways is a very important matter, get involved.
The
Beginning of the End to "Partnering"? - A News Item
from NCE
A recent article in New
Civil Engineer was bought to my attention, as an item that I would be
interested in, and I certainly was.
The article was in the edition of NCE dated 23-30 of September 2009,
being titled "Keeping Them Keen". an article by Anthony Oliver
relating to an interview with Steve Morgan who is the new Capital Programmes Director of BAA.
Occasionally I feel that my jottings regarding the state of the
Highways Maintenance procurement are falling on deaf ears, no closed
ears. However, I know this to be untrue, as I am aware that many, many,
people involved in the "real" side of highways maintenance agree with
my views, but have little opportunity to influence overall decisions.
But we often think we are largely being ignored by the "suits" that
now seem to run both sides of the industry.
So how refreshing to read this article in NCE where a very senior
"suit", and he must be regarded as that, expresses the views contained
in this article.
I particularly appreciated, "It's not a matter of let's hold hands
and sing kumbaya around the camp fire - it's more about defining
what we are doing and rewarding performance."
I would like to think from this, that a part of "defining performance"
includes actually specifying materials, e.g. runway surfacing, and sampling and
testing to be able to reward performance.
If you wish to read this article for yourself and you do not receive
NCE, the good thing about the New Civil Engineer website is that most
of it is "open", and you can read much of the content of editions of the
journal on line, without having to disclose all your personal
details.
So to save me transferring a long website address just put the
keywords "Steve Morgan" and "NCE" into a good search engine of your
choice, and I know Google works for me, and you will be taken to the
appropriate page containing the article, and in another area of the site you will be able to
read letters/responses that the article has generated.
Please take the time to read this article, I think that you will enjoy
it, well some of you will, especially if you are beginning to despair of the current
arrangements in highways maintenance, especially highway surfacing. I
found it particularly interesting to note that it is large elements of "private
industry" that seems to be leading the way away from "partnering"
agreements to cut costs and improve performance, while government and
local authorities seem to be still embracing such arrangements.
Thank you NCE, it would be nice if more of the other Highways
Maintenance related press had similar content and the same open approach to
sharing information.
Not having cause to visit this website for some time, I found it very
informative as to what has been happening in the industry at the
higher "management" level. It was revealing and
disappointing, but it
is unfortunate that I did not find it surprising.
It is well worth taking some time to read other "related" articles and
comments to be found on this website
I know that I only used to play somewhere in the First Division
compared to the top four management spot in the Premier Division, that
the
gentleman in the article that I refer to occupies, but the principles are the same.
A good well specified contract takes a lot of beating in providing
clarity for both sides to work to, but of course you need people who
understand fully what they are doing to provide such a contract.
I always found the "real" people in the production/supply and
contracting side of the industry also preferred this option.
It was the "hairy/fairy" management people, on both sides I hasten to
add, who preferred "partnering" arrangements as it made up for their
lack of any "real" knowledge.
I am led to believe that large and important Highways Maintenance
contracts are these days won on the eloquence of their presentations,
the sartorial elegance of the presenters, and having the appropriate
social contacts, rather than any proof of the knowledge/expertise that
a bidding "team" is able to provide to the client,
allegedly representing the taxpayer.
It is good that I am retired and not part of this "unreal" situation
that we have arrived at today, in what is basically a very "real"
industry.
You see, I can remember, in what seems a different age, when we used
to have contractors and suppliers into the office for a serious "arse
kicking" session (a highways maintenance
technical term) if they had failed to deliver what was in the
contract, and things would get sorted out pretty quickly or they would be off the
approved list.
"They" are probably invited in for counselling these days.
The commercial side of the the industry is a tough industry, it is
fully able to take the criticism, survive, and produce the materials
that you the engineer want, that is, if you know what you want.
But you need somebody equally tough to keep them in line, it is just
the way it has been for a very long time, until lately.
Allowing the decline of the engineering capability of local authority
engineering departments, and consultant engineers, and their ability to
supervise, and replacing them with media/public relation types is not
the answer.
This decline in engineering supervision will only promote a lowering
in quality of supplied materials and workmanship, because if the "good
guys" putting in the effort to supply good materials and workmanship
do not see this investment rewarded with a continual supply of
work/contracts, well I leave you to draw your own conclusions.
If you wish to maintain the integrity of the UK highway network,
the relevant authorities must also put in place the appropriate
investment to support the Engineers and Engineering Technicians,
quality does not happen by itself.
It is like saying, as long as you have laws, you do not need a police
force, I just do not think it would work, do you?
Price Fixing
in the Construction Industry
It was while browsing
the internet regarding the item above, that I understood the extent of
the "illegal bidding" that had been conducted in obtaining
construction contracts by companies large and not so large.
Yes, I had seen the brief news item on the television news, and not
given it a lot more thought. I know these things happen from time to
time, but they are usually individual situations.
After visiting the website,
www.oft.gov.uk/news/press/2009/114-09, and seeing the length of
the list of the companies that had been fined by the Office of Fair
Trading it is concerning how endemic this type of practice is in the
UK construction industry.
I am going to exercise caution and limit any comments I may have, I
leave you to download the list from the Office of Fair Trading website
and draw your own conclusions.
However you may wish to look at the comments and letters that an
article regarding this situation published in NCE and available on
their website.
The illegal bidding (price fixing) did not come about of its own
accord, it would have been arranged by "people" active in the
industry.
It is sad that the industry has come to this, but it has happened
because it is able to happen. Were there really no checks in place to
have a reasonable idea of what the work, whether large or small,
should cost?
Perhaps I am spoilt and worked with a team that had a pretty good
idea what work should cost. We often used to get concerned if a price
was too cheap, knowing that it would be difficult to provide the
standard we expected for the price that had won the bid.
And we certainly knew if a contract had been over priced.
I am not making this up, line marking was a particular example of low
prices causing concern. When
you worked out the total length of the line to be laid the average
thickness and width, the quantity of good quality thermoplastic
needed, the amount of good quality drop on glass beads to provide the
minimum 100mcd's retro-reflectivity that was specified for the marking,
the cost of the labour, plant, and traffic control, there was little
margin if any left.
But the point I am making is, that between us in "The Highways
Maintenance Team" I worked in, we had this combined knowledge and the ability
to exercise it. Are there any such teams left? I would like to think
so, but I doubt it, and even if there are, there is a good chance that
they will disappear in the next round of local authority "savings".
In my opinion there certainly is not much "intelligent client" left in
the Highways Agency. I can remember when a visit from the Highways
Agency engineering team to our own Motorways and Trunk Roads Section,
to check that everything was progressing as it should be, used to put
the fear of God into them, because these visiting teams really knew
about highway engineering.
This is of course when local authorities had the responsibility,
funded by government, to locally maintain the motorways and trunk
roads in their area.
I still find it amazing that practically all of the motoring public do
not realise that the maintenance of motorways and trunk roads for all
intents and purposes has been privatised by Government, and they are
having a jolly good attempt at doing it to Local Authorities.
Use of the
Internet, (the information is out there, if you know how, and are
willing, to search)
Already, with the items
above you will have noticed how I have accessed appropriate
information that has been posted on the internet, not from any dubious
blogs or dodgy websites, but from mainstream sources who obviously
want you, and that is everybody "you", to have access to the
information.
I am of the opinion that there is less "information" available for
young and inexperienced engineers and technicians within the
"engineering office", and what there is, is not shared across the
office as it used to be, on the basis that "knowledge is power". It is
also my belief that the commercial side of the industry is trying to
play down the engineering aspect of promoting a material or process,
replacing it with "marketing", in the form of "pieces of paper" to
define engineering ability, and plain old ordinary advertising in all
its forms.
I particularly notice the plethora of "awards" that are available
these days, it seems somebody is always "winning" something, and there
is a jolly party attended by all the various "PR" people, with some
prominent "speaker" picking up a nice cheque for orating the views of
those gathered there.
In response to all the "hype" creeping into the industry I would
suggest that you look to the internet to obtain a fuller and more
balanced view of the materials and processes that are out there
to choose from.
There are organisiations and websites out there who do provide more in
depth information of the products and process that they provide or
support.
I will give you a couple of examples of the information out there if
you take a little time browsing and you have some knowledge of highway
materials, if you do not have such knowledge then you do need a website such as mine, or
similar, to point you in the right direction.
This is what I like to think I do, not necessarily put answers on a
plate, but point you in a direction where you are able to find
information that will allow you to become capable of making your own decision.
(It would be better still if you could discuss
items with a knowledgeable and experienced Materials Engineer, but
still make up your own mind, but I think I may have mentioned this
before.)
It also highlights the fact that it is not possible to tell you
everything, there is too much to tell, you have got to be capable of
finding it out for yourself.
Example 1:
Website items like this also remind me of items of information that I
have taken for granted as accepted knowledge, that everybody
dealing with bituminous mixtures still possess, e.g. the use of
limestone filler in hot rolled asphalt (HRA), and other bituminous
mixtures.
This filler is a significant
factor in making hot
rolled asphalt the premium surfacing material that it is, or can be.
So take a look at,
www.britishlime.org/tech_asphalt01.php
Although not dealing with hot rolled asphalt surface course in
particular, it does concisely cover the benefits of using limestone
filler in bituminous mixtures.
In my early days it was custom to use ground limestone as the filler
element of a hot rolled asphalt "recipe", whether a "recipe"
recipe or a "design" recipe.
(Whatever bituminous mixture a supplier produces
they do need a "recipe" to be able to manufacture a consistent
product.)
Over the years it has now progressed to the situation that the filler
element of the mixture is more likely to be "aggregate dust" from the
manufacturing quarry, often material fed back from the dust extraction equipment on the
plant.
I am not saying that this is the situation on all plants, and the
filler portion could well be a blend of "in house" filler and bought
in limestone filler.
But what I am saying is that before you condemn all hot rolled asphalt
surface course as liable to rutting, in the wheel tracks of heavily
trafficked roads, that you fully investigate the nature of the HRA
surface course that has been used, including the nature of the filler
element.
You will also need to investigate the source of the sand (fine
aggregate) and the viscosity of the binder, but this item is primarily
to draw your attention to the filler portion of a HRA surface course,
all other things being equal.
While you are on the British Lime website you may want to explore all
the other information (with excellent downloads) that is available
relevant to highway construction, e.g. lime stabilisation.
Example 2:
Now contrary to my earlier statement, "it
is also my belief that the commercial side of the industry is trying
to play down the engineering aspect of promoting a material or
process, replacing it with "marketing", in the form of "pieces of
paper" to define engineering ability, and plain old ordinary
advertising in all its forms."
There are companies that are not following this trend, and do
produce quite comprehensive websites to inform you of the products
that they market, their intended use, and "product information sheets"
to tell you the composition of the actual product.
This gives the purchaser/client the ability to compare individual
products that are on offer, and indeed sample and test to check the
quality of the material that they are receiving against that
advertised.
I would particularly draw your attention to the highways/line marking
section of this website as it is the area I have mostly explored, but
other topics on the website seem to follow the same approach.
I am sure that there are many other websites, that offer similar
information, and you will find that good search engines do favour
websites that have good content in them in their main "open"
searching.
Suffice to say this is an example of a good "open" website (i.e.
you do not have to enter all your personal details before you can
access it) where an Engineer or Engineering Technician will find
"real" information on the products listed, in what I found, a fairly
logical manner.
So, as an example of what I think is a good commercial website take a
look at,
www.adbruf.com/home.htm, and search
for similar websites in relation to the product or process that you
are looking for, and form your own conclusions.
And, I have to add, as a retired Materials Engineer, look for
information in relation to British Standard specifications.
Winter
Maintenance for 2009-2010
I
would also like to describe the "Use of the Internet", as a means of
trying to follow what is happening in relation to products and
processes that are being introduced on to the Highways Maintenance
market, and how "change" is happening all the while.
Not to the basic product or service, but how it is "marketed". to make
it more profitable or appear more "sexy". (A
marketing term I believe, and I hope the presence of this word on my
website does not attract the "wrong kind" of browser.)
Winter Maintenance being a very important sector of Highways
Maintenance, I present this as a topic in its own right.
This wander around the web, and it is is a long tale so I hope you are
sitting comfortably, all started when I noticed that a link I had on
my,
Road Salt for Winter Maintenance page
no longer
worked.
It appeared that the website, and more important the title, that had
been displaying the products and services of the largest road salt
supplier in the UK was no longer in being.
In fact the current website title had reverted back to the company
title, rather than the all embracing but not specific title it had
recently
held, so the website was still active under the name it had held
before the grand marketing ploy.
What immediately struck me was that this company was now owned by a
very large American based company, you were even able to download
their 2008 Annual Report if you wished.
I do not know when this occurred but I certainly did not notice this, at this time of the year in 2008.
Once on the website my curiosity led me to the list of products to see
if the much marketed and allegedly enhanced road salting material
containing an agricultural by product from the sugar production
industry was still
offered for sale. I noted that the complete road salting product was no longer
offered under its highly promoted brand name, but was still available
as a proprietary product using the quite innovative company brand
name.
This discontinuation of the original highly promoted brand name as a
"total" salting material may be because of a significant amount of
criticism that had been associated with the storage, use, and claimed
benefits of the product.
It appeared that there has been a change in marketing strategy, and a
little more searching led me find that there was still an active
website that promoted and supplied information regarding the
agricultural by product used to coat rock salt. The addition of this
modifier claiming to provide a number of benefits to the basic rock salt
element, and therefore more than offsetting the increased cost of the
modified road salt. The claims for this rock salt modifying product are documented on their
website.
It is my opinion that there is a distancing between the rock salt
industry and supplier/promoter of the agricultural by product, but it
is for you to decide for yourself.
What I did appreciate finding was a comprehensive specification for
this salting product, as well as specifications for other products
supplied, on the salt mining company
website, which means that you can sample
and test to ensure that you are being delivered the material you are
paying for.
These specifications being very useful if you are not using,
BS 3247:1991:Salt for
spreading on highways for winter maintenance,
as your specifying document.
The story now takes a turn, as during my searching I had come up with website items that
interested me, relating to a "partnership" between a large university
in the "North West" and the large road salt supplier I have already
mentioned. This partnership dates back to 2003-4 and was facilitated
through a company that appears to be government funded (I gave up
trying to find out its exact sponsor) and a number of universities.
It appeared that a newly qualified graduate, one of many who take part
in the overall "partnering" arrangement had been put in charge of
a project to "explore the technologies of GPS (global positioning
systems) and vehicle weighing and salting sensors" to produce a system
to improve the efficiency and profitability of the road salt company.
It appears that this "system" worked well until last winter when we
actually had a prolonged spell of relatively severe winter weather
when the "system" fell down badly.
Now in all my browsing and seeing images of smiling people in suits at
"partnering" meetings I did not see one reference, or picture, of a
guy or girl from the "sharp end" who I know, certainly in my
area, predicted failure of this system on the basis of their practical
knowledge and experience over many years.
Now I am not, and never have been one of the "winter maintenance
team", but I did provide support in certain areas of sampling, testing
and calibration and so rubbed shoulders with these people on a regular
basis, and they appeared to talk a lot of sense to me, apart from
being some of the "hardest" guys who worked for the authority.
Yes I am talking about the actual guys who drove the gritters, they probably
know a bit about actually getting salt onto the road surface during
bad weather.
It is my opinion that most people could run a winter maintenance
programme when we have practically no winter, but when it all hits the
fan it is the people with the experience and "grit" if you will excuse
the pun who "get you out of the shit", (another
"real" highways maintenance technical term).
And if I may make just a couple of brief comments, of my own, on
winter maintenance.
It is that reducing the number of salt stockpiles and centralising
them may do wonders for increasing efficiency for precautionary
salting, but when conditions do get bad and accidents prevent the
gritters from getting back to the stockpile to refill and they have no
other source of salt it does not seem so clever.
The second point being, that supplying salt "on demand" works as long
as the whole country does not "demand" it at the same time.
We will all, once again, be watching the performance of the winter
maintenance industry carefully this coming winter. I wonder how many
"managers" are already crossing their fingers.
You will note that I have omitted the names of the various "players"
in this scenario because pointing fingers at individuals was not the
point of the item, but it is to highlight how those in charge of
Highways Maintenance are losing touch with reality.
I believe that this same scenario of the involvement of academics and
public relations people, not to forget the accountants, is being played
out in many aspects of highways maintenance, and it is producing few,
if any, benefits.
But I do see plenty of examples of it not working, and of course the
main example being proprietary, Thin Surface Course Systems.
In my opinion the modern procurement "system" has to change, i.e. revert to sound engineering practice, before the extinction of the species of
"real" highways maintenance people, at all levels, have
given up or have gone to maintain the network for the "force" in the
firmament.
There may come a time when there is no one left to get you out of the
brown smelly stuff, and even governing authorities, small or large,
could falter on this issue. Perhaps I need to get more political.
BS
EN 12591:2009:Specifications for Paving Grade Bitumens
Here is an important piece of news which I thought was of sufficient
importance to add to this newsletter rather than leave it until the
next edition, in truth I never know if my enthusiasm will survive to
produce a next edition.
In my recent internet browsing on highways related matters I found
that,
BS EN 12591:2009:Specifications for paving
grade bitumens, has recently been published to supersede
BS EN 12591:2000 which has been
withdrawn.
A "Guidance Brochure", describing the changes and additions
to the 2000 edition is available on the
RBA (Refined Bitumen
Association) website.
Once on the RBA website follow the toolbars for "Bitumen" and then
"Testing and Standards", and the document is available to download as
a .pdf file.
(While there you may also like to download the guidance document
relating to polymer modified bitumens.)
On reading this note you will find mention to the fact that there is
now included in BS EN 12591:2009 a table,
Table NA 1, that provides
guidance on the use of paving grade bitumens from 20/30 pen. to
160/220pen. "for use in the construction and
maintenance of roads and airfields in the UK".
Table NA 2 gives guidance on softer, less viscous, bitumens.
My interpretation of these "informative" tables is that they are a
common sense suggestion that you specify a penetration grade bitumen
from the "normal/standard"
range of available penetration grade bitumens.
It following that you do not use cutback bitumen in bituminous
mixtures if it can be avoided.
However,
I feel that I still have to mention the recent introduction of
in-plant blending of penetration grade bitumens, this procedure being
introduced in the final years of BS 594 and BS 4987, and has followed
into the new European specifications for bituminous mixtures.
I find the introduction of this practice a little concerning, as since
this time I have noticed examples of highly
rutted HRA surface course patching, which clearly should not be
occurring.
In my opinion a 100pen. bitumen is an acceptable, pragmatic, compromise bitumen for a HRA
surface course, in a patch, in difficult laying conditions, in cold
winter weather. It will give the gang a much better opportunity of
laying and compacting a successful surface course to any hand laid
patch. But this material, containing a 100pen straight run bitumen
will not rut to the degree that I have observed on some occasions
recently.
Is trying to "blend" a small quantity of bitumen in a small
tonnage of material going to be beyond the capabilities of some plants,
or some operators, I do not know. But my observation of heavily rutted HRA surface course patching has increased since the permitted
introduction of in plant blending of penetration grade bitumens, it
may be a coincidence but I think not.
Of course, the bottom line is that the penetration of the bitumen in
the mixture shall be that which is specified whether the source has
been a tank holding a straight run bitumen of the grade required, or if
the bitumen in the mixture is a result of blending two other
components to produce a bitumen of the specified viscosity.
It is my fear, that in reality, the arrival at the correct penetration
grade bitumen in the bituminous mixture through blending may not always be
achieved.
So, I had hoped to see some further reference to in-plant
bending of bitumen, but I was disappointed. There is a very brief reference to
"loading through an in-line blender" and
"a procedure for checking the performance of the
blender", but it is very brief and not at all specific.
I am further "troubled" by the comment at the beginning of the
document that states, "This European Standard
does not directly address 'cohesion, adhesion and setting ability'",
this is more fully detailed in the "Introduction" to the
specification.
There is a slightly larger reference to in-plant blending of bitumen in,
NHSS (National Highway Sector Schemes for
Quality Management in Highway Works) 15 : The Supply of Paving
Bitumens.
NHSS 15 can be downloaded from the UKAS website, and the
information relevant to in-plant blending can be found in,
Section 8.2.4 - Monitoring and Measurement of
Product
This depth of knowledge, in an ideal world,
should not be part of the purchasers responsibility, you should be
receiving the materials that you
have specified.
Note what I have just said, if you do not know what material you
require that is not the responsibility of the Supplier, talk to
your
Materials Engineer for guidance.
However, I found it was only by having a fairly thorough understanding
of what was happening in the "industry", and in the changes in
specifications, that was I able to be aware of what may be causing the
problems on the highways and sites I had some responsibility for.
Whether
you think knowing your craft is important I leave for you to decide,
fortunately I can just keep a watching brief out of a sheer interest
in what was my profession for most of my life.
But it does disturb me to see what is in my opinion a decline in the
quality of the highway network of the UK, well, at least in the area
that I drive.
It is not all down to reduced funding, as funding was increased
recently, for a time, and I did not perceive any benefit, and it is certainly going to get
tougher in the next few years.
A bit of "real" engineering by "real" engineers and technicians would
go a long way to holding off the worst of the reduced funding, but I
am probably not supposed to say that.
I am probably supposed to say we
need a conference on the subject followed by a few working parties,
followed by another conference, which all the "suits" will attend and
hardly any "proper" engineers.
And then, I guarantee that the result will be a unanimous "whinge" for
more money, which I realistically and reluctantly admit the highway network does need, but
at this time you are
not going to get it.
So what you will get needs to spent correctly, and
perhaps an investment in suitable engineers and technicians based on
qualification and/or experience will produce a better return on the
available budget.
Motto of the Month
News is what somebody somewhere wants to
suppress, all the rest is advertising.
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