THIS IS A GUIDE TO "TRL" PREFIXED REPORTS RELEVANT TO HIGHWAYS MAINTENANCE,
GIVING AN INDICATION OF THEIR CONTENT
There are
reports prefixed TRL and not those prefixed TRRL, this is due to a
name change from the Transport and Road Research Laboratory to
the Transport Research Laboratory.The TRRL reports are earlier than the TRL reports, and reference to TRRL reports can be found on a separate page.
The TRL website address is www.trl.co.uk, and information relating to most TRRL/TRL reports can be found there, in the publications section, even if some of the older ones are difficult to track down.
But before you rush off to the excellent TRL website it will probably help you to have a browse through this page where you may well find a little extra information relevant to a particular report and the subject it covers.
These report references being particularly appropriate to actual highways/roads maintenance, and road pavement construction.
To find specific information in this page please use your browser "find" function to perform a search using an appropriate keyword or words.
NOTE - References to a new, interesting, TRL Published Project Report (PPR) has been added to this list on the 22-01-2010, I could tell you where it is, but you may learn more about the many other excellent available TRL publications if you have to look for the new addition.
TRL - TRANSPORT RESEARCH LABORATORY / FOUNDATION
The TRANSPORT RESEARCH LABORATORY is a trading name of the TRANSPORT RESEARCH FOUNDATION group of companies.
The TRL is now privately owned.
The TRANSPORT RESEARCH FOUNDATION is a company limited by guarantee.
A company limited by guarantee is a company set up where the "members" of the company have a liability limited to the amount set down in the "memorandum of understanding" of the company.
The amount is usually quite small, however I believe the company is still liable to a claim against its assets.
TRL Abstracts no. CT89.1 - AGGREGATES IN ROAD CONSTRUCTION UPDATE 1996/98
This issue of
Current Topics includes over 75 abstracts of reports, conference
papers, books and journal articles which focus on the effects of both
concrete and bituminous road surfacings, including texture treatments,
specifications / testing, skidding resistance, durability, and noise
generation from vehicle tyres.
A predominant theme is thin surfacing treatments.
These items have been selected from the material added to the
Transport Research Laboratory's Library Database between 2005 and
2008. Much of the relevant English language published literature from
the UK, USA, Australia and Europe is included; some of the non-UK
literature is included courtesy of the OECD International Transport
Research Documentation (ITRD) database.
The reproduction of
the summary of this report placed on the TRL website is acknowledged.
TRL Abstracts no. 68.1 : Deterioration of road surfaces update ( 1994 - 1996 )
This is an interesting collection of abstracts from the TRL Library's Database of Worldwide Published Information relating to Deterioration of Road Surfaces.
Because they are only abstracts they only give an indication of what is in the published document, but none the less it remains interesting reading and points you in the right direction for further study.
Current Topics in Transport : Report No. 130 : Rubber in Bituminous Pavements (1991 - 1997)
This is an interesting collection of abstracts from the TRL Library's Database of Worldwide Published Information relating to Rubber in Bituminous Pavements.
It includes many abstracts relating to the use of rubber "crumb" from the recycling of old car tyres.
Current topics in transport : Report No. 89.1 : Aggregates in Road Construction Update (1996 - 1998)
This is an interesting collection of abstracts from the TRL Library's Database of Worldwide Published Information relating to Aggregates in Road Construction
Current topics in transport : No.40.3 _ Bituminous Road Design and Construction Update
This is an excellent collection of abstracts relating to bituminous materials used in road construction and maintenance.
The abstracts range over most aspects relating to bituminous based products, and how they may be manufactured and used.
I find I can always discover a few abstracts that lead me to obtaining the full report or paper,.
I can recommend the abstracts on the use of recycled high density polyethylene (HDPE) and low density polyethylene (LDPE) as a bitumen additive/modifier.
Application Guide AG26 (Version 2) - Footway and cycle route design, construction and maintenance guide
This version published 2003, it has been produced by TRL under a contract placed by the Highways Agency.
This is a very comprehensive guide covering most aspects of footway and cycle route design, construction and maintenance.
TRL CONTRACTOR REPORT 151 - LIME STABILISATION
This report is quite comprehensive in discussing all aspects of using lime or cement, or a combination of both as a means of stabilising in-situ material to replace an imported granular capping layer.
It incorporates current specifications for use in Britain as well as describing specifications used in the U.S.A..
There is also information on work already undertaken with in-situ stabilisation.
THIS REPORT IS WELL WORTH READING FOR ANYBODY CONTEMPLATING SOIL STABILISATION.
TRL CONTRACTOR REPORT 292 - NIGHT DEFLECTOGRAPH
This report describes an investigation into the validity of night-time deflection measurements.
It was basically concluded that night-time surveys could replace day-time surveys with little or no loss in accuracy, providing specified temperature limits are adhered to.
It was also concluded that modifications to present temperature correction procedures would improve the accuracy of the deflection method for both night time and day time surveys, and of course, you cannot see as well in the dark.
This may well provide more basic practical problems such as correctly logging / identifying the road sections that you are testing.
TRL CONTRACTOR REPORT 320 - POROUS CONCRETE ROADS
TRL CONTRACTOR REPORT 341 - HIGHWAY EMBANKMENTS
This report is in the form of a set of guidelines for the design and selection of construction methods for highways on soft alluvial deposit.
Constraints on a design, such as, cost, performance, construction time and enviroment all need to be taken into account in selecting a possible embankment site and method of construction.
TRL Project Report 109 - EVATECH H Polymer modified bitumen
This is a report of tests carried out on "EVATECH H", a polymer modified bitumen produced by Alfred McAlpine Quarry Products, who commissioned the report.
It is intended as a replacement for 50pen straight run bitumen in hot rolled asphalt materials, and for use in THIN SURFACINGS.
The limited increased benefits of using this binder may NOT be regarded as sufficient for the increased cost over British Standard materials, it would be best to read the report and draw your own conclusions.
TRL Project Report 114 - A quantitive assessment of a nuclear method for binder content determination
As the title suggests it is a report into the use of a nuclear method for the determination of the binder content of bituminous materials.
This is a much quicker method, approximately 15-20 minutes, but there can be problems with initial calibration, and you still need to strip binder from mixes to be able to do aggregate gradings, so it may be of limited use.
TRL Project Report 12 - The testing and performance of surface dressing binders for heavily trafficked roads
A large part of this report is details on road trials incorporating differing binders and processes, and the results obtained.
Use of modified binders is referred to.
TRL Project Report 13 : Acceptable weather conditions for laying bituminous material
This is a report on the effect that prevailing weather conditions has on the laying of bituminous coated materials.
In particular temperature and wind speed, related to the thickness of the bituminous layer and viscosity of bitumen.
The report is quite detailed in the depth to which it deals with the subject and the inter-relation of the factors mentioned.
Specifications at the moment are almost exclusively temperature based, i.e. maximum and minimum temperatures for particular materials, and minimum air and road surface temperatures.
The report suggests wind speed should play a greater part in specifying laying conditions.
TRL PROJECT REPORT 30 - VEHICLE WEIGHT LIMITS - ROAD PAVEMENT WEAR - FAILURE
This report was produced as a result of a questionnaire survey of goods vehicle operators conducted by TRL.
The survey data was processed in such a manner as to give estimates of numbers of goods vehicles, amounts of goods vehicle travel, perhaps most importantly an indication of increased road wear attributable to the increased weight limits.
TRL Project Report 55 : Evaluation of a performance specification in road construction
TRL PROJECT REPORT 60 - SITE INVESTIGATION
This is a study in the efficiency of SITE INVESTIGATION PRACTICES.
This study was conducted because of concern of costs incurred on jobs because of lack of information that should have been supplied by adequate SITE INVESTIGATION, and was not.
TRL Project Report 61 : Assessment of Multiphalte, the Shell Multigrade bitumen
This is a report produced by TRL, as a result of a commission from Shell Bitumen, to assess the performance of a proprietary Shell bitumen marketed under the trademark of "MULTIPHALTE".
Most of the work in the report is based on trials done in 1987 on the A38 at Burton.
A number of lengths of HRA wearing course were laid at the same time as a trial that was being conducted on POROUS ASPHALT.
If you require information on MULTIPHALTE I would suggest you obtain and read a copy of this report.
TRL Project Report 65 : EVALUATION OF STONE MASTIC ASPHALT (SMA): A HIGH STABILITY WEARING COURSE MATERIAL
This is a MUST if you wish to know about the original concept of SMA, and how to specify it.
It includes a large amount of VERY INTERESTING back ground information regarding the development of SMA.
TRL Project Report 66 : EVALUATION OF "ENROBE A MODULE ELEVE" (EME): A FRENCH HIGH MODULUS ROADBASE MATERIAL
An excellent report giving details of the original concept of stiff roadbases, which was a relatively fine graded aggregate structure with quite a high binder content of a very stiff bitumen.
Later development work in the U.K. changed this original concept and failures resulted in trials, and actual use.
(Note - The use of a proprietary EME more closely related to the original French design for this material is now being promoted, it is still too early to assess whether the "new" EME's for use in the UK have proved successful.)
TRL Project Report 75 : Cold-mix bituminous materials for use in the structural layers of roads
This report covers a number of trials using bituminous materials coated using bitumen emulsions.
It describes the trials, problems encountered and the performance of the materials on site and in laboratory testing.
It also includes useful information on cold mix emulsion macadams already in use in Europe and America, including "Grave Emulsion" used in France.
TRL Project Report 78 : Tests for voids and compaction in rolled asphalt surfacing
This is an interesting and useful report on voids in bituminous materials in general, and in hot rolled asphalt wearing course in particular, and it explains the methods of calculating voids quite well.
TRL Project Report 79 : Road trials of thin wearing course materials
The title is a bit misleading, as only two materials have been trialed, and of those two materials there were seven sites of "Safepave" and one site of "UL-M", with some hot rolled asphalt wearing course as a control.
It is still a report well worth reading for the factual information that is presented on these two products and the principles of thin surfacing in general.
TRL Project Report 87 : ACCELERATED AND FIELD CURING OF BITUMINOUS ROADBASE
The work sponsored by the HIGHWAYS AGENCY, B.A.C.M.I. and the ROAD BITUMEN ASSOCIATION (RBA).
The report is a study of the curing, (hardening), of bituminous binder used in roadbases, and the development of a simple accelerated curing test able to be performed in the laboratory that reflects the on site curing characteristics of binders.
TRL Published Project Report PPR021 - Measurement of the acoustic performance of road surfaces
TRL Published Project Report PPR023 - Comparison of tyre/road noise for a range of surfaces in Leicestershire
This a comparison of generated tyre noise from a number of different types of generic surfacing materials, hot rolled asphalt, stone mastic asphalt, coated macadams and surface dressings using TRITON as the noise measuring vehicle.
TRL Published Project Report PPR066 - The early life skid resistance of asphalt surfaces
TRL Published Project Report PPR066 - Pavement wear factors
TRL Published Project Report PPR073 - Friction tests on contaminated road surfaces
TRL Published Project Report PPR077 - Tyre/road noise - Assessment of the existing and proposed tyre noise limits
TRL Published Project Report PPR082 - A study of water movements in road pavements
TRL Published Project Report PPR084 - Edge deterioration on local roads
TRL Published Project Report PPR127 - Road foundation design for major UK highways
TRL Published Project Report PPR144 - Wehner Schultz machine - First UK experiences with a new test for polishing resistance in aggregates
TRL Published Project Report PPR148 - Surface texture measurements on local roads
TRL Published Project Report PPR187 - Test procedures for durability and adhesion in asphalt - The US Mechanistic - Empirical Pavement Design Guide
TRL Published Project Report PPR205 (2008) - Early Life Skid Resistance - An assessment of accident risk
"For some years it has been suspected that new asphalt surfacings may have different skid resistance properties to surfaces that have been in service for some time. This is thought to be due to the presence of a film of bitumen binder on the new surface that is eventually removed by weathering and traffic. New types of surfacing introduced in the mid 1990's have led to concerns that the risk of early-life skid resistance problems, and the time that any effects last, may have increased. This report provides the results of a study to investigate if a link could be observed between new surfacings and accident risk. The study used a combination of an analysis of accidents before and after resurfacing of Highways Agency (HA) network, and from other Highway Authorities. The findings from this study are generally consistent with the physical phenomena that have been measured on new asphalt surfacings. Neither of the approaches in the study identified widespread problems with modern asphalt surfacings in their early life, but there is evidence of a small increased accident risk in some circumstances."
The reproduction of the summary of this report placed on the TRL website is acknowledged.
TRL Published Project Report PPR219 - Road trials to determine the effect of de-icers on skid resistance
(ISBN: 978-1-84608-749-3 ISSN: 0968-4093)
Highway authorities have a duty to keep highways free of ice and snow and endeavour to meet this duty by treating roads with de-icers. It is unlikely that de-icers will reduce grip to levels that would occur with ice or frost on the road, but concerns have been expressed by some road users that de-icers, particularly repeated applications that cause them to build up on the road surface, can adversely affect the skid resistance and increase the risk of skidding accidents compared with that in normal conditions This report describes a study in which a test methodology was established to investigate the effect of de-icers on skid resistance. The study included measurements of skid resistance on sites with hot rolled asphalt and proprietary thin surfacings that had been treated with de-icers. Four de-icers were included in the investigation, namely dry untreated rock salt, rock salts treated with Eco-Thaw and Safecote, and pre-wetted salt (rock salt pre-wetted with brine). The measurements were made with Highway Agency’s Pavement Friction Tester (PFT) and a GripTester. The tests with the PFT showed that de-icers reduce skid resistance at low sliding speeds (20 – 40 km/h) compared with a wet road with no de-icer present, but at higher speeds (60 km/h and above) skid resistance with de-icer present is greater than on a normal wet road. The significance of these changes was assessed with reference to the seasonal increase in skid resistance from summer to winter and the investigatory level. The GripTester was found not to be suitable for general use in detecting any adverse effects due to de-icers. Since it was not possible to determine the effect of all the potential effects of de-icers on skid resistance, including a build up of de-icer and associated detritus during prolonged cold spells with repeated applications but little rain, further tests with the PTF are recommended.
The reproduction of the summary of this report placed on the TRL website is acknowledged.
TRL PPR220 An assessment of the effect of de-icers on skidding accidents
(ISBN: 978-1-84608-750-9 ISSN: 0968-4093)
During periods of frost and snow, the formation of a layer of ice on a road surface will lead to a large reduction in friction, and increase significantly the risk of skidding accidents. For this reason, highway authorities have a duty to keep highways free of ice and snow and endeavour to meet this duty through winter service operations. However, concerns have been expressed by some road users that de-icing operations, particularly repeated operations when de-icers can build up on the road surface, can adversely affect skid resistance.
The Highways Agency commissioned TRL to investigate the effect of de-icing operations on skidding accidents and skid resistance. This report describes a desktop study to address the first objective of the research project: to identify where and when a reduction in skid resistance due to repeated de-icing operations has been experienced on the Agency’s network and any common factors.
The data were analysed in three stages:
1. an overview of winter accidents in comparison with other times of year using the national accident data;
2. comparison of the accident densities and characteristics of winter accidents on an Area basis with and without the use of de-icers using the Highways Agency’s database that reports winter service operations in combination with the accident data;
3. comparison of the accident rate on routes on days with and without the use of de-icers. This analysis used traffic data in addition to the data used in the second stage.
The reproduction of the summary of this report placed on the TRL website is acknowledged.
TRL PPR324 Surface requirements for asphalt roads
(ISBN: 978-1-84608-753-0 ISSN: 0968-4093)
HA/QPA/RBA Collaborative Programme 2004/07: Surface requirements for asphalt roads
This report
describes research for Topic 1, "Surface requirements for asphalt
roads", of the 2004–2007 phase of the Collaborative Programme
sponsored by the Highways Agency, the Quarry Products Association and
the Refined Bitumen Association. The primary objective was to assess
whether current aggregate specifications related to skid resistance
are appropriate for modern asphalt surface courses. A database study
attempted to compare the in-service performance of existing thin
surfacings with current specification requirements for Polished Stone
Value (PSV) and traffic. However, the main emphasis of the work was on
a series of road trial sites where thin surfacings using the same
coarse aggregate in different sizes were laid for direct comparison.
Monitoring of the development of skid resistance over a range of
speeds commenced at nine sites representing different PSV/traffic
combinations. A laboratory study was made of the polishing of
aggregates of different sizes using the Wehner-Schulze test, a
technique new to the UK. Samples of aggregates used in all the trial
sites, plus cores taken from one site after a period of trafficking,
were tested. A short study was also made to assess making comparisons
of the spray generated by traffic on different thin surfacings. A
mobile photographic method was investigated that provided a feasible
way of measuring spray in traffic under moderate rainfall but not when
it was heavier and the surface texture appeared flooded. Currently,
the trials are at different stages of polishing towards their
equilibrium skid resistance level and this is necessarily an interim
report. Monitoring of the trial sites is continuing in the next phase
of the Programme.
The reproduction of
the summary of this report placed on the TRL website is acknowledged.
TRL PPR393 Measuring skid resistance without contact, 2008-2009 progress report
The title describes the content of the
report, it is interesting reading, whether this "without contact"
procedure it will eventually replace "contact" testing still depends on
a great deal of work being done, and even then the answer may be it is
not a viable option.
The principle of the method is using optical images taken of the surface
at "road speeds" and being able to interpret these images, using
appropriate computer "software", as an accurate assessment of the skid
resistance of the road surface. The need is for the optical image to be
an exact representation of the road (aggregate) surface and the software
to produce a true conversion of the optical information for all
surfaces.
This report indicates the progress that has been made to date.
TRL Project Repot PR/CE/143/95 : REHABILITATION OF IN-SERVICE FOOTWAYS
(This is an UNPUBLISHED report.)
This report is a study into footway design and construction, based on information from answers to a questionnaire distributed to local authorities.
The report is fairly comprehensive in the varied approaches to footway construction and maintenance, and includes a lot of useful information, but if you already possess good reference books on this subject it does not cover that much new ground.
FOOTWAY DESIGN GUIDANCE : NEW CONSTRUCTION
(This is an UNPUBLISHED report.)
This is an excellent report giving good information on footpath design for different situations, and It includes designs for block paving which give cause for concern, I am unable to comment further as it is an unpublished report.
It may be possible to get copies from TRL.
TRL PROJECT REPORT PR/CE/178/95 - HAUNCH - RECYCLING
This is an unpublished report, based on work associated with three trials where recycled materials were used in the haunch construction.
There is much useful information in the report with regard to the materials used, and types of testing apparatus and methods of test used.
Also assessment of how successful the various materials have been.
TRL PROJECT REPORT PR/H/05/92 : EQUIPMENT AND METHODS FOR ASSESSING THE CONDITION AND CONSTRUCTION OF ROAD HAUNCHES
This report is almost a listing of all types equipment currently available for testing haunches prior, during and following construction, equipment that is capable of determining surface regularity, strength, compaction and layer thickness.
TRL Project Reort PR/H/40/93 : Use of Alternative Materials in Road Haunches : A Review of Past Practice
The objective of this report is to review the experience of local authorities in re-using conventional road making materials, industrial by-products and other alternative materials for repairing haunches.
TRL PROJECT REPORT PR/H/43/93 - FOOTWAY MAINTENANCE - SURFACE REGULARITY
This report is a "review of profile monitoring techniques".
This means it is a review of approximately 25 pieces of equipment capable of recording surface regularity, all but two pieces of apparatus are not suited to footway testing, but are for carriageways.
The equipment most suitable, ( but still under development), for footways are :-
The BRITISH GAS PROFILE METER, and the, WDM FOOTPATH PROFILER.
TRL PROJECT REPORT PR/H/58/93 - SCRIM - GRIPTESTER - SKID RESISTANCE MEASUREMENT
(This report is UNPUBLISHED at 31/12/93.)
This Project Report has been prepared for the County Surveyors Society Griptester User Group.
The TRL Test Track was used for comparison of the GRIPTESTER and SCRIM machines.
TRL also analysed the results gained from the test track runs to produce the information in this report.
As this is an UNPUBLISHED report no mention of conclusions drawn will be referred to here, but they are "interesting".
Copies of the report may be obtained only by direct personal application to TRL.
TRL PROJECT REPORT PR/H/66/94 - FOOTWAY PROFILES
This is a report on the testing and comparison of two FOOTWAY PROFILOMETERS, these being:-
1) BRITISH GAS ROAD PROFILE METER
2) WDM FOOTWAY PROFILOMETER
These two machines were put through various trials, both on TRL test sites and in actual footway situations.
The results of each machine were compared against "true" results and each other.
TRL PROJECT REPORT PR/H/85/94 - FOOTWAY PROFILES
The contents of this report form the basis of an end product / performance specification for a FOOTWAY PROFILOMETER.
This report will include the necessity for criteria a FOOTWAY PROFILOMETER will need to comply with in order that it shall accurately measure defects in footways.
It will also include maintenance and calibration procedures in order that the profilometer shall retain its accuracy in use.
It shall also produce information in a form that can be processed by an IBM compatible P.C..
TRL PROJECT REPORT PR/H/88/94 - FOOTWAY DESIGN - FOOTWAY FAILURE
This report reviews the present methods for the design of footways and the causes of deterioration.
It also considers new approaches to the design of footway construction
TRL PROJECT REPORT PR95 - FOOTWAY PROFILES - CARRIAGEWAY PROFILES
This is Part 1, of 3 Reports, Footway Maintenance, A Review of Profile Monitoring Techniques
This report covers a number of profile monitoring techniques, most of them being suitable for highways rather than footways.
It also incudes a provisional specification for a Footway Profilometer.
This report gives a good background description of the all techniques if you need information on carriageway profile monitoring.
TRL PROJECT REPORT PR96 - FOOTWAY PROFILES
This is Part 2, of 3 reports covering FOOTWAY PROFILES.
This is a report on the testing and comparison of two FOOTWAY PROFILOMETERS, these being:-
1) BRITISH GAS ROAD PROFILE METER
2) WDM FOOTWAY PROFILOMETER
These 2 machines were put through various trials, both on TRL test sites and in actual footway situations.
The results of each machine were compared against "true" results and each other.
TRL PROJECT REPORT PR97 - FOOTWAY PROFILES
The contents of this report form the basis of an end product / performance specification for a FOOTWAY PROFILOMETER.
This is Part 3, of 3 reports covering FOOTWAY PROFILES.
This report will include the necessity for criteria a FOOTWAY PROFILOMETER will need to comply with in order that it shall accurately measure defects in footways.
It will also include maintenance and calibration procedures in order that the profilometer shall retain its accuracy in use.
It shall also produce information in a form that can be processed by an IBM compatible P.C..
This research project was funded by the County Surveyors Society and the Highways Agency.
TRL PROJECT REPORT R/D190/1 - THE EFFECTIVE SEALING OF CRACKS IN BITUMINOUS SURFACINGS
This report has been prepared for the Highways Agency by Rendel Palmer and Tritton in conjunction with TRL.
It is a fairly comprehensive report covering all aspects of joint and crack sealing in bituminous materials.
It plays particular emphasis on SKID RESISTANCE and TEXTURE, these being the factors that are necessary for safety to road users.
It includes a useful technical appendix on joint / crack sealing products and contractors.
TRL Report 121 - Laboratory testing of road-marking materials
This is a report on procedures being developed for the laboratory testing of road marking materials to replace the on site trials on the A1 at St. Neots in accordance with BS 3262:Part 2.
The testing regime being developed to include laboratory tests on :-
Erosion (Wear Index),
Rate of spreading of laid line,
Skid Resistance Value,
Luminance Factor,
Retro-Reflectivity,
The report is useful reading on the above characteristics.
TRL Report 125 - Trials of high-friction surfaces for highways
The report gives information on the performance of the differing systems on the market, epoxy-resin, polyurethane-resin, acrylic-resin and rosin ester, this information being obtained from a series of road trials throughout the U.K..
Laboratory tests have also been devised to simulate accelerated wear under trafficking.
TRL REPORT 129 - An economic and technical appraisal of geosynthetic soil nails
TRL REPORT 134 - A STUDY OF FOOTWAY DESIGN - CONSTRUCTION - MAINTENANCE
This a very comprehensive report, ninety five A4 pages, prepared by TRL.
It is funded by the County Surveyors' Society and the Highways Agency.
It is an excellent report and to be recommended.
It covers all aspects of footway design, construction, maintenance, management, profiles, materials, inspection, costing, research, etc., etc..
TRL REPORT 157 : RHEOLOGICAL PROPERTIES OF POLYMER MODIFIED BINDERS FOR USE IN HOT ROLLED ASPHALT WEARING COURSE
Published February 1999
Authors :- J.C.Nicholls, D.R.Gershkoff, J.Caswell
TRL Report 176 : Laboratory tests on high-friction surfaces for highways
A number of laboratory test have been devised to test for the quality of HIGH FRICTION surfacings with the pupose of assessing various materials for having the necessary level of quality to receive HAPAS approval.
This report describes the tests and testing procedures, but does not suggest the levels of performance materials must attain to receive the HAPAS approval / certification.
TRL Report 216 : Road Haunches : A Guide to Re-usable Materials
This is a very comprehensive report, including information on recyclable materials, haunch design and construction practice.
It was derived from information obtained from actual trials using recycled materials in haunch construction, these trials being documented in TRL PROJECT REPORT PR/CE/178/95.
TRL Report 218 : Assessment of AXOFLEX, the Redland thin asphalt surface course
This report includes a great deal of information from trials performed in France.
However as at 4/8/98 this material has not received approval from the Highways Agency for motorway and trunk road work in the United Kingdom, this is because a 2 year trial on a principal road, and subsequent satisfactory report has not yet taken place.
TRL Report 231 : Road trials of high modulus (stiff) base for heavily trafficked roads
This report describes trials of high modulus (stiff) roadbase materials inroad pavement construction, 15pen., 25pen., and 35pen., bitumen binders were used in the trials.
The increased stiffness of these materials increases the ability of the roadbase to spread load and therefore thinner pavements can (in theory) be designed, thus providing a saving in cost of road construction.
TRL REPORT 237 - COMMERCIAL VEHICLE TYRE ADHESION - TYRE NOISE
Includes information on tyre noise.
TRL Report 250 : Design of long-life flexible pavements for heavy traffic
This report is a study of existing and past methods of flexible pavement design to assess how successful the various designs have been after many years of trafficking.
It indicates that flexible road pavements that were initially well constructed have maintained their strength, and in some cases gained strength.
Therefore it suggests well constructed flexible pavements will have a long structural life providing deterioration of the surface course receives remedial treatment at the appropriate time.
TRL Report 261 : The long term performance of a surface dressing trial on A413, Amersham.
Various test lengths of type and size of chipping were laid for study after trafficking, the various results are recorded and possible conclusions drawn.
TRL REPORT 264 - REVIEW OF POROUS ASPHALT TRIALS
TRL Report 292 : Assessment of MILLOM HITEX, the Bardon thin asphalt surface course
This materials is not too different from a 10mm. open graded macadam in appearance although it does contain limestone filler and a modified bitumen as the binder.
TRL Report 298 : Mechanical retexturing of roads, a study of processes and early-life performance
TRL Report 299 : Mechanical retexturing of roads, an experiment to assess durability
TRL Report 303 - The evaluation of tests for repair materials used on concrete pavements
This report covers a range of laboratory tests to establish the likely performance of the various materials on the market, a number of representative types of material have have been tested and conclusions drawn.
It was also emphasised the extreme importance of good workmanship and correct weather conditions at the time of the work.
TRL Report 308 : The determination of the acceptability of selected fragmenting materials for earthworks compaction
TRL Report 314 : Road trials of stone mastic asphalt and other thin surfacings
TRL Report 315 : Specification trials of high performance hot rolled asphalt wearing course
TRL Report 322 : Polished stone value of aggregates and in service skidding resistance
TRL Report 324 : The effectiveness of the utility reinstatement specification
TRL REPORT 329 : Use of non-destructive testing for the assessment of newly constructed concrete pavements
This was a study of tests undertaken on the surface of pavement concrete that were considered able to determine the strength of pavement concrete, and most tests gave a fair degree of accuracy in indicating early strength of the concrete.
TRL Report 367 : High and low speed skidding resistance : the influence of texture depth
Included in this report is a description of the PAVEMENT FRICTION TESTER (PFT).
The PFT is the standard apparatus for testing the friction of road surfaces in the USA, it is a towed trailer with both wheels having hydraulically applied disk brakes which are activated by compressed air.
It uses the locked-wheel principle in accordance with ASTM Standard E274 (1990)
The TRL now has one of these machines, but with only the left side wheel fitted with the braking system.
TRL REPORT 386 : Design guide and specification for structural maintenance of highway pavements by cold in-situ recycling
The authors are :- L.J.Milton and M.Earland, Published 1999
TRL Report 408 : Enabling the use of secondary aggregates and binders in pavement foundations
Published 1999
This report details work performed by the TRL on secondary aggregates, such as :-
China clay sand
Blastfurnace slag
Steel slags
Pulverised fuel ash
Gypsum
Cement kiln dust
These materials were formulated to a number of blends and the most successful were used in full scale trials at the TRL's Pavement Test Facility (PTF).
A number of secondary aggregate mixtures were found to be successful in producing strong road pavement foundations, and full scale road schemes have been recommended on these materials.
TRL Report 424 : Detailed chemical analysis of lime stabilised materials
Published 1999
TRL REPORT 434 : ASSESSMENT OF THINPAVE A BARDON THIN ASPHALT SURFACE COURSE - THIN SURFACING
THINPAVE is an open textured 10mm. bituminous macadam with a 100pen. binder that has been modified by the addition of rubber at the time of mixing.
The added rubber being in the form of latex.
Further trials are currently taking place where a pre-modified bitumen, I.e. "Olexobit" from BP has been used as a replacement for rubberised bitumen.
TRL REPORT 435 : ASSESSMENT OF SMATEX A BARDON THIN ASPHALT SURFACE COURSE - THIN SURFACING - SMA
SMAtex is based on a STONE MASTIC ASPHALT (SMA), but it is sufficiently different in its design and the thickness at which it is laid from the original German concept of SMA that the impervious nature and durability of SMAtex may well be less than that original concept.
TRL REPORT 447 - SULPHATE SPECIFICATION FOR STRUCTURAL BACKFILLS
TRL REPORT 456 : DEVELOPMENT OF A PERFORMANCE-BASED SURFACING SPECIFICATION FOR HIGH PERFORMANCE ASPHALT PAVEMENTS
This is a large and comprehensive report with a great deal of information relating to actual road pavement trials performed on the TRL road pavement test facility.
A number of designs and bituminous mixtures where included in the trials and associated testing was quite thorough.
Included in the report is a large amount of information relating to wheel type ( super single and twin wheels) and the damaging effect each type has on the road pavement.
TRL REPORT 494 : THE BEHAVIOR OF ASPHALT IN ADVERSE HOT WEATHER CONDITIONS
TRL REPORT 497 : THE DESIGN OF POROUS ASPHALT MIXTURES TO PERFORMANCE RELATED CRITERIA
TRL REPORT 499 : MATERIAL PERFORMANCE OF POROUS ASPHALT, INCLUDING WHEN LAID OVER CONCRETE
TRL REPORT 505 - SWELL TEST REQUIREMENTS FOR LIME STABILISED SOILS
TRL REPORT 516 - MITIGATING THE DISRUPTION CAUSED BY UTILITY STREET WORKS
TRL REPORT TRL519 - SPECIFICATION OF PULVERISED-FUEL ASH FOR USE AS GENERAL FILL
TRL REPORT TRL523 : GRANULAR AND BITUMINOUS PLANINGS MIXTURES FOR CAPPING
This is a fairly comprehensive report on trials performed at the TRL Pavement Test Facility (PTF) on bituminous planings and blends of materials including bituminous planings.
It includes useful information on pavement layer testing devices, including :-
Falling Weight Deflectometer, German Dynamic Plate (GDP) and the Prima 100
TRL REPORT TRL535 : FOOTWAY MAINTENANCE MANAGEMENT
TRL Report TRL536 - Resurfacing a motorway with porous asphalt :
Effects on rural noise exposure and community response
TRL Report TRL545 - Development of a novel traffic calming surface "Rippleprint"
This report details the stages involved in developing traffic calming surfaces with particular reference to surface that has a sinusoidal wave pattern created on the surface of the road the design of the wave is such that noticeable vibration is cause within the vehicle cabin without cause excessive noise to the close environment of the road where it has been positioned.
TRL Report TRL557 - Durability of thin asphalt surfacing systems : Part 1 - Initial findings
TRL Report TRL566 - Basic oxygen slag as surface course aggregate : An investigation of skid resistance
TRL Report TRL572 : Long-term performance of reinstated trenches and their adjacent pavements -
Part 1 : Literature review
TRL Report TRL573 : Long-term performance of reinstated trenches and their adjacent pavements -
Part 2 : Long-term performance of reinstatements in the highway
TRL Report TRL576 - Quieter concrete roads : construction, texture, skid resistance and noise
Exposed aggregate concrete road surfaces compared with hot rolled asphalt, stone mastic asphalt and thin surfacings.
TRL Report TRL598 - Development of new materials for secondary and recycled aggregates in highway infrastructure
The contents of this report forms part of the DTI/WRAP sponsored Aggregates Research Programme to support the development of construction markets for secondary and recycled aggregates.
TRL Report TRL611 - A guide to the use and specification of cold recycled materials for the maintenance of road pavements
This is a comprehensive report offering guidance on cold recycled materials that are "bound" using hydraulic (cement, slag, pulverised fuel ash) binder or foamed bitumen, or combinations of these binders.
Although the report places emphasis on performance testing of road pavement materials produced by cold recycling, it also stresses the importance of the initial design, and its documentation.
An outline specification for a number of possible cold recycled materials is included in the Appendix to the report.
TRL Report TRL615 - Development of a more versatile approach to flexible and flexible composite pavement design
This document deals with the idea of increasing the versatility of road pavement design to give the engineer a wider choice of materials and design configurations.
This increased versatility will lead to more economic designs by allowing new materials, recycled materials and a wider range of secondary aggregates and binders to be used.
It offers the potential to enable stronger foundations to be constructed, incorporating hydraulically bound materials, providing the option of reductions in the more expensive surfacing layers.
TRL Report TRL622 - Accidents and the skidding resistance standard for strategic roads in England
It is largely on the basis of this report that changes have been made to HD 28/94 to produce the revised edition
HD 28/04.
TRL Report TRL636 - The application of "Enrobé à Module Élevé" in flexible pavements. (2005)
This is an interesting report covering trials carried out at the TRL Pavement Testing Facility, under simulated continuous wheel loading, comparing the stiff, binder rich, French bituminous mixture "Enrobé à Module Élevé" (EME) with more conventional coated macadams, the opportunity was taken to undertake a study of wheel track "trench" repair using EME.
I would suggest that you read this report thoroughly before you use this bituminous mixture, which is likely to be only available as a proprietary material, on a critical site.
TRL Report TRL638 - A model set of asphalt sustainability indicators
This report recommends a "model" set of sustainability, and other, indicators that could be adopted and developed by the asphalt industry.
TRL Report TRL639 - Guidance on the development, assessment and maintenance of long-life flexible pavements
A very informative report that describes the concept of long life road pavements, the new concept of robust pavements, and how existing, less well constructed pavements, can be maintained so that they may become long life pavements.
TRL Report TRL645 : Feasibility of recycling thin surfacing back into thin surfacing systems
This report provides information on a number of trials and processes to assess the feasibility of recyling the premium quality aggregate present in failing thin surfaces into new thin surfacings.
With the implementation of the asphalt package of European standards and the withdrawal of the equivalent British Standards in January 2008, the basis of the tests called in the Specification for Highway Works will have to change. This harmonisation of test methods for bitumen and asphalt will mean that numerical values in requirements may need to be adjusted in order to maintain the same level of performance as prior to the change.
This report relates to work undertaken to determine the nature of any potential/necessary adjustments, in particular with the testing of the texture depth of pavement surfaces, wheel tracking and the storage stability of polymer modified binders, amongst others.
A pilot trial has taken place using CKD in the production of both binder course and surface course materials.
There were no exceptional problems to producing a good looking mat. The overall conclusion is that CKD can be successfully used as the added filler in routine asphalt mixtures, but that it varies as a product between sources (the extent of the consistency of properties from a single source has not been investigated).
TRL (UN-NUMBERED REPORT) : RECYCLING IN TRANSPORT INFRASTRUCTURE
An excellent report covering ALL aspects of undertaking recycling processes in road maintenance and construction.
It includes advice and guidance on all the necessary rules and regulations that must be complied with in any recycling process.
The report also describes example of types of recycling already being undertaken.
TRL APPLICATION GUIDE AG39 - SPECIFICATION FOR FOAMED CONCRETE
TRL RESEARCH REPORT 298 CRUSHED ROCK FINES IN HOT ROLLED ASPHALT
This is a study of trials carried out on the A303 near Mere in Wiltshire.
Trial plots with wearing course mixes incorporating crushed rock fines, different penetration binders and amounts of binder were laid and tested over a period of six years, the results are tabulated and discussed in this report.
TRL RESEARCH REPORT 349 - CONCRETE JOINT SEALANTS
This is a report to study the performance of 18 different concrete joint sealants, and results obtained both in the laboratory and on site are tabulated and discussed.
This is a useful piece of reading for anybody considering work on concrete joints.
TRL RESEARCH REPORT 355 - FAST TRACK CONCRETE PAVING
This is a very useful report on this subject describing the process, with mix designs and details of a full scale trial.
TRL RESEARCH REPORT 358 - MODIFIED DBM ROADBASES
This report covers trials where the bitumen binder has been modified in some way, e.g. polymer and metallic modifiers.
Also stiffer than conventional bitumens, (i.e. 50pen.), where included in the trials.
The report concluded that there was no significant improvement in the roadbases incorporating polymers, there was some improvement with the use of metallic modifiers, although metallic modifiers in other trials have given variable results.
This work confirmed the improvement in roadbase performance using harder grades of bitumen.
It did however point out these materials require mixing and rolling at higher temperatures to ensure adequate coating and compaction.
TRL RESEARCH REPORT 361 - SOIL COMPACTION
This report has investigated a number of methods and devices for monitoring the compaction of earthworks, in relation to the Series 600 Earthworks of the DOT Specification for Highway Works, and the reinstatement of trench backfills.
This report summarises research carried out on:-
1) the nuclear density gauge.
2) the Clegg impact soil tester.
3) the TRL dynamic cone penetrometer.
4) Bomag Terrameter compaction meter.
5) Dynapac compaction meter.
It was generally thought that density measurement was the only acceptable method of assessing compaction at this present time.
I acknowledge copyright by TRL of the following summary of Road Note 39 - 6th. Edition, obtained from their website.
"Road Note 39 is a guide for the design of surface dressing for roads throughout the United Kingdom (it is NOT prepared as, nor should it be used as, a specification).
This Sixth Edition of the Road Note is produced by a Panel representing all sides of the industry, with the Chairman and Secretariat provided by the Infrastructure Division of TRL Limited.
The following extract emphasises the importance of the Road Note: "Surface dressing can be used successfully on all types of roads, from the country lane that carries only an occasional vehicle to trunk roads and motorways carrying thousands of vehicles a day.
It provides a simple but cost-effective form of maintenance (Carswell, 1994; Nicholls & Frankland, 1997; Milton et al., 2001). Unfortunately, the attention paid to design, control, supervision and aftercare is frequently less with surface dressing than with more expensive forms of construction. Lack of attention to detail shortens the useful life of a surface dressing; the benefits of adequate control, particularly in the period when traffic is first allowed on the new surface dressing, cannot be emphasised too strongly."
The principal differences from the Fifth edition are: CEN standards (European standards have been introduced for aggregates and bitumen and are being introduced for surface dressings and so there are a lot of changes to the standards that need to be referenced); Nomenclature for aggregates (European standards for aggregate have introduced a nomenclature for aggregates of d/D, where d and D are the minimum and maximum sizes, so that the use of a/b for multiple system surface dressings would now become more complex and has been discontinued); Nomenclature for emulsions (the European standard for bitumen emulsions has replaced the K1 70 classification by several, more specific classifications); Cut-back binders (cut-back binders are no longer generally available from binder suppliers in the UK and so have been removed, leaving all binders to be one of the varieties of bitumen emulsion); Spread rates for proprietary polymer-modified binders (polymer-modified bitumen emulsions now represent a major part of the market so the rates quoted in the Road Note with an assumed binder (solids) content of 67 % can be adjusted by multiplying by 67 over the proportion declared for bitumen emulsions with a different proportion); Traffic categories (the weight of passenger vehicles has increased, particularly with the use of people carriers and off-road vehicles becoming more widespread so that the proportion of vehicles over 1.5 t is increasing and the number of roads with very low flows of medium and heavy vehicles is reducing); Simplicity (as far as practicable, the method has been simplified without changing the basic methodology and, in particular, the use of categories for binder spread rates has been discontinued); and Electronic documentation (where documents are available on the web, the web address is given that can be used as a link, although no distinction is made between those that can be downloaded freely and those that require payment, either for each document or as a subscription)."
I would suggest that everybody associated with the design and laying of surface dressing should have ready access to a copy of this document, it is regarded as the "bible" of surface dressing.
This Road Note identifies the different techniques for overlaying concrete pavements and bridges with asphalt (bituminous mixture), assists in the choice of treatment for a specific situation and gives advice on how to maximise the durability of the treatments. The basic durability of the asphalt material used for the overlay covered by
Road Note 42.
This Road Note gives general guidance on the procedures for maximising the durability of asphalt (bituminous mixture) pavements. Whilst it is appreciated that some concepts may not be practical in all circumstances, particularly for emergency repairs, the ideas should be used as ideals that are strived for whenever practicable.
TRL Supplementary Report SR 754 - Nuclear gauges for measuring density of dense roadbase macadam : report of a working party