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VOL. 5 / No. 4 / December, 1997
Quarterly Newsletter of the Finnish Highway Transportation Technology Transfer Center, FinnT2
Address: Finnish National Road Administration, FinnT2, P.O. Box 33, 00521 Helsinki, FINLAND
Fax Int. 358 204 44 2675. E-mail: [email protected] Editor: Arto Tevajarvi, Tel. Int +358 204 44 2032
Editor-in-Chief: Jarmo Ikonen, Tel. Int. 358 204 44 2118
Contents
- REGIONAL T2 SEMINAR BUSY WITH STRATEGIC PLANNING
- THE FINNISH ROAD STRUCTURE RESEARCH PROGRAMME; TPPT
- ACCELERATED PAVEMENT TESTING
- MODERN COMPACTION TESTING EQUIPMENT
- REMIXER STABILIZATION IN RECYCLING OF OLD ROAD STRUCTURES
- R&D Projects of Finnra's Traffic and Road Engineering Unit
REGIONAL T2 SEMINAR BUSY WITH STRATEGIC PLANNING
THIS YEAR, STRATEGIC PLANNING HAS GAINED DISTINCTION AMONG THE TECHNOLOGY TRANSFER CENTERS IN THE BALTIC REGION. THE CONSEQUENCE WAS THAT STRATEGIC PLANNING ISSUES RECENTLY PLAYED A DECISIVE ROLE AT THE 10th REGIONAL T2 SEMINAR. THE VISION, GOALS AND STRATEGIES OF THE THREE NATIONAL TECHNOLOGY TRANSFER CENTERS AS WELL AS THE REGIONAL CENTER WERE DRAFTED DURING THE MEETING. THE DOCUMENTS GENERATED IN THE EVENT ARE, AT THE MOMENT, UNDER FINALIZATION.
The 10th semiannual regional T2 Seminar was arranged by the Latvian Technology Transfer Center in Riga, Latvia, on November 4-5, 1997. In addition to the host center, the Estonian Technology Transfer Center, the Lithuanian Technology Transfer Center, the Finnish Technology Transfer Center and the Federal Highway Administration of the USA were represented in Riga.
Three presentations delineating the ongoing changes in the Latvian road community were given in the beginning of this meeting: Principles, tasks and realization of the Latvian road branch reforms by Mr.Talis Straume, Director of Road Department in the Latvian Ministry of Transport; Coalescence of Latvian road maintenance offices by Vilnis Urbanovics, President of State Joint-Stock Company �Roads of the Central Region�; The implementation strategy of the European normatives in road branch of Latvia by Mr. Guntis Graveris, Head of Normative Department of State Enterprise (Road Research).
The topical work plan issues were, of course, included in the agenda of the meeting. The directors of the centers gave status reports on the realization of the Work Plans 1997 and the Work Plans 1998 were jointly drafted after having heard the Estonian, Latvian and Lithuanian needs for next year activities.
JARMO IKONEN
ROAD STRUCTURE RESEARCH PROGRAMME IN FINLAND PROGRESSING
The Finnish National Road Administration has in her strategic research action plan (1995-2001) an extensive road structure research and development program called TPPT, the total budget of which is about 11.5 million USD.
Overall, the research program is progressing well: it includes the development of new foundations, improved road structures against loading and frost, quality of design and construction and minimizing environmental loading in road construction materials and structures.
Pic. 1: Light embankment from expanded clay under construction.
Wide international cooperation is connected with this programme, too. A great deal of experience from abroad (Sweden, USA, Great Britain and France) has already been applied to Finnish research practice.
The most important joint project with Sweden was the purchasing of a common accelerated pavement testing machine, the Heavy Vehicle Simulator (HVS). In addition we opened information sharing between the countries and cooperated in joint practical research.
It has been calculated during the preparation process of the research programme that by better quality in design and construction of structures, it is possible to make substantial savings (5-10%) in annual maintenance costs. Also the structures developed in this program will be much more durable and homogenous and the new materials will have fewer negative environmental impacts.
ARTO TEVAJ�RVI
THE FINNISH ROAD STRUCTURE RESEARCH PROGRAMME; TPPT
TPPT is a strategic research programme of the Finnish National Road Administration (Finnra) for the years 1994-2001. The programme is carried out by the Technical Research Centre of Finland (VTT). The total budget is about FIM 58 million, including the additional costs of constructing test roads and a small amount of external support.
TPPT is the Road Structure Research Programme which investigates the operational level of service of a road and its achievement and maintenance as economically as possible, and with the least environmental load.
The crucial task of TPPT is to develop road structures so that the present level of service can be achieved in the future with increasing economy. Thus, TPPT includes research relating to foundation conditions and their characterization, pavement structures, frost structures and foundations as well as matters concerning quality in production and design. In addition, investigations in TPPT will concern the environmental loads caused by structures and the life-cycle of the structures. Many analyses require the modelling of the behaviour of materials and structures and the investigation of external stress factors.
OBJECTIVES AND APPROACH
The main target of TPPT is to reduce the annual maintenance costs of a road by 5 -10 % depending on the road in question and, at the same time, to decrease the amount of unexpected damages of a road by 50 %. It should be possible to reduce the environmental impacts of construction and structures as well.
The evenness of a road and thus its service life are regarded by TPPT's hypothesis as being influenced mainly by the geotechnical load bearing capacity and sensitivity to frost penetration of the foundation or the old structure. The loading capacity of the road, on the other hand, is regarded as having considerably less significance than the above factors.
WAY OF WORKING
The recearch progresses from investigations of foundation conditions and materials to tests of trial tracks and roads. As a result, new behaviour models, dimensioning systems and codes of practice for structures and materials are obtained.
Pic. 2: Vertical stabilization of peat
The organization contains 5 special working groups, the executive committee and the international advisory committee. The programme manager is assisted by the technology committee. The special working groups are: 1) Characteristics of subgrade and subsoil, 2) Material models, 3) Structures and their behaviour, 4) Production quality, and 5) Life cycle cost analysis. They contain some 35 projects in a year.
The main structures are engaged with the bituminous layers, cement treated layers and their combinations; frost sensitive materials and their modification; lean cement and lime treated materials and reinforcement materials. The functional criteria of the end results deal with the evenness of a road in a long run. Thus, the basic selection criteria of a structure base on the annual costs containing all the maintenance measures as well.
STATE OF RESULTS
The TPPT programme is at about the stage of mid point. The materialistic studies will be finished this year. Next year will be the last year for larger field tests. The general description of the functional designing system has been made and the quality assurance system is still under construction. The life cycle cost analysis as a key tool for the life time dimensioning of roads is now under construction.
Life time modelling is a significant key task in TPPT. At the moment, the life time models of the loading capacity issues are quite ready for life time design processes. It is a part of the EU project called PARIS. The modelling of the frost behaviour in terms of the structural durability is still under progress. The bases of the process are totally novel. The settlement models are still under construction.
The TPPT materials are unbound, bitumen stabilized, cement stabilized, a combination of cement and bituminous materials (composite materials) and frost sensitive materials. The models have already been developed.
The measuring of subsoil and subgrade behaviour is, in principal, done. The measuring systems consist of segregation potential measurements, water content measurements by electric resistivity and the loading capacity by the radius of curvature of dynamic loading.
Pic. 3: A ground radar device is being equipped for field surveys.
INTERNATIONAL COOPERATION
The TPPT programme has many international connections. There is the international advisory committee which evaluates the progress and the contents of TPPT every year. Last year TPPT lounged a comprehensive cooperative research project with the Swedish Road Administration and the Swedish Road and Transport Research Institute in the field of accelerated deterioration of road structures with a common facility (HVS device). TPPT has connections to the Minnesota road research programme and to the corresponding CRREL (Cold Regions Research and Experimental Laboratory) programme with the HVS device. Very important links have been made in connection with the EU's PARIS programme.
INTERNATIONAL SYMPOSIUM
The first international symposium on the TPPT programme will be held in Helsinki on June 8-9, 1998. The programme consists of the results achieved by that time.
CONTACT PERSONS
For more information, please contact Aarno Valkeisenm�ki, Project Coordinator (tel. int. +358 20444 2140, fax int. +358 20444 2154), or Tuomo Kallionp��, Project Secretary (tel. int. +358 20 444 2144), at Finnra or Asko Saarela, Project Director (tel. int. +358 9 456 4970, fax int. +358 9 463 251), at VTT.
Mr. ASKO SAARELA, Technical Research Centre of Finland (VTT)
While the Finnish Road Structures Research Programme (TPPT), 1992-2001, was being planned it was soon found out that it cannot be carried out successfully without Full Scale Accelerated Pavement Testing. During the previous and very successful paving research program (ASTO), 1987-1993, the laboratory results could be verified within a winter or two because it handled only the wearing course and mainly its properties against studded tyres. Roads are usually structurally designed for twenty years and thus the results from structural test roads take a long time, from ten to twenty years.
The Nordic countries have traditionally had close co-operation for instance within the Nordic Road Association (PTL), especially in its permanent committees. PTL also had an ad hoc group on accelerated pavement testing in the late 1980�s; no real co-operation within a common facility was economically possible at that time and the result was only a published report. Close co-operation has included visiting researchers and joint research projects. VTT also has carried out a large research project financed and ordered by the Swedish Transport Research Commission. The Swedish National Road Administration has also ordered research projects from VTT. The Nordic countries had a common coordinator as a loaned staff at SHRP during the whole research program.
The researchers of the Technical Research Centre (VTT) in Finland have participated in international research projects where accelerated pavement testing has been used. They came to the conclusion that the testing facility should be linear and movable and it should have complete temperature control. The bids for offers were sent to all potential manufacturers. After the evaluation of the proposals it was obvious that all the alternatives were exceeding the financing available.
Finnra and VTT started discussions with the Swedish National Road Administration (SNRA) and the Swedish Road and Transport Institute (VTI). The Swedish counterparts had informed their interest for an accelerated testing facility earlier. The result from the negotiations was positive; a Full Scale Accelerated Testing Facility will be bought together on a 50/50 bases.
After a careful technical and cost/benefit analysis the decision was made; a Heavy Vehicle Simulator (HVS) was ordered from South Africa. It was delivered to VTT this year and started the first test at the end of June. HVS will be used in Finland up to September 1998, after which it will be taken to Sweden for one e year, then back to Finland for a year and so on up to the end the research programmes.
HVS can move at walking speed on a test area and can be moved as a semi-trailer on longer distances. Thus, it can be taken to a ferry in Helsinki and transported easily to Stockholm and further on to Link�ping, where VTI is located. The test wheel is either dual tyres or a wide base tyre. The wheel load is 30-110 kN corresponding to axle loads 60-220 kN (6-22 tons). The normal operating speed is 12 km/h and if run in bi-directional mode there are 25 000 wheel passes within 24 hours and, if run uni-directionally, half of that. The trafficked length is about 7 meters. The total length of HVS is 23 m, width 3.5 m and height 4 m. The total mass is 46 tons.
A very important feature of VHS is the temperature control for both heating and cooling. The pavement temperature can be kept constant in the range of -5�C to +35�C. 10�C has been selected as a standard temperature which is close to the mean temperature in Southern Finland. HVS can be run electrically or by diesel if electricity is not easily available, like on the the road under construction where it will be taken next spring.
In order to get all of the benefits from the common facility, the co-operation between Finland and Sweden must be very effective. The basic principle is that 50 % of the tests should be common and 50 % own. With that principle we will have 75 % efficiency.
It is very important to standardise materials, running process and measurements in order to get good comparability between Finnish and Swedish tests. Fine sand is used in most tests as subgrade, and both parties have worked hard in order to find similar sands. The running process (temperature, lateral wander, standard wheel loads etc) has been agreed on. The measurements systems are the same and all measurement devices (except FWD) will be similar. Detailed planning of a common database has been started. It will have different levels and, for instance, measurement signals will be saved. The main part will be open to doctoral students of Finnish and Swedish Universities; in fact two Swedish students have already started their work.
The formal co-operation is done in Steering, Program and Operative groups. The Steering group includes decision makers from each four owners, the Program group consists of experts from all four parties and handles research programs, etc. The Operative group handles practical and technical questions and members are experts from VTT and VTI. This three level system seems to work well.
For further information, please contact Mr. Matti Huhtala at VTT, phone int�l +358 9 4564960, fax int�l +358 9 463251 or e-mail [email protected].
Mr. MATTI HUHTALA, Technical Research Centre of Finland (VTT)
MODERN COMPACTION TESTING EQUIPMENT
A very interesting new basic piece of equipment for laboratory work is the gyratory compactor. A Finnish company has developed this equipment for over 11 years. It has recently been defined and introduced in some standards: the SHRP/AASHTO designation in the USA and the draft CEN standard in Europe.
Increased traffic loads call for higher quality requirements in road construction. The behaviour of materials under compaction and traffic loads is studied in advance in a laboratory to make sure that the construction will succeed economically and reliably.
Pic. 5: An ICT-150 gyratory compactor.
The gyratory compactor makes it possible to compact specimens of different mixes in road construction: asphalt pavement mix, unbound or stabilized soil, and concrete. This compaction method simulates field compaction, e.g. rolling, better than traditionally used tests. It also gives better repeatability.
The Finnish National Road Administration (Finnra) has investigated road construction materials with the ICT gyratory compactor in its road regions for nearly 10 years. One road region has used the equipment to determine the optimal binder content of asphalt pavements and in the quality control of roller compacted concrete. Another road region has also used the ICT equipment in investigating soil layers stabilized by cement or granulated blast furnace slag. According to the experiences the equipment suits well for these purposes.
Nowadays, the ICT equipment is also used in other investigations and tests within Finnra, e.g. in studying aggregates in asphalt mixes and in soil materials used in road building. With the instrument it is possible to make homogenously compacted and comparable specimens for demanding measurements. Thus, it is possible to improve the repeatability of results considerably.
On the western coast of Finland the aggregates available for road construction often are of poorer quality than in the other parts of Finland. The equipment in question has also been utilized in investigating these materials, see Finnra publication no 53/1994: Applicability of Poor Quality Crushed Rock.
In Imatra, near the Russian border, the construction of 10 kms of new motorway was completed in 1997. In this site, a total of 300 000 square meters of stabilized layer with cement content of 3.2 % was constructed. During the work 182 specimens were made in six weeks. The specimens needed to be compacted within an hour after the mixture was mixed. The transportation of the specimens also took some time. The compaction of the two specimens by the ICT took 10-15 minutes.
In Lapland the climate is colder than elsewhere in Finland, which causes some problems. The specimens have been compacted by the ICT into a plastic tube and then tube suction tests have been carried out. Specimens by the ICT have also been made for water permeability tests. These test results are important in understanding the frost behaviour of materials.
The quality of bituminous pavement materials can be controlled by the ICT. Skilled research personnel can solve many problems related to the use of construction materials by the help of the equipment. Typical users are the road authorities, universities and research laboratories.
Laboratoire Central des Ponts et Chaussees (LCPC) in France arranged comparison tests of gyratory compactors on the European market. The ICT belongs to the best category, when considering the test results separately or looking at the differences in sensitivity to the shearing resistance of a mixture.
The manufacturer of the equipment, Invelop Ltd, has supplied the product to 12 countries.
Further information, please contact: Invelop Ltd, Telakkatie 18, 57230 Savonlinna, Finland;
tel. int. +358 15 557 987, fax int. +358 15 557 990, or Kari Lappalainen, Finnra Headquarters,
Production/Laboratory, 00521 Helsinki,
Finland; tel.int. +358 20444 2544,
fax int. +358 20444 2019.Mr. ANTTI PAAKKINEN, Invelop Ltd
REMIXER STABILIZATION IN RECYCLING OF OLD ROAD STRUCTURES
The Lapland Road Region (the Arctic Area) in the Finnish National Road Administration in cooperation with a paving company and a pavement equipment manufacturer has been developing a new bitumen stabilization method in which the load durability of old and declined paved roads is restored by reusing old materials existing in the road structure. Only some minor additional materials are needed.
MATERIALS IN DAMAGED ROADS ARE STILL RECYCLABLE
The fatigue of a road structure can be seen as damages in road surfacing such as ruts, crazings, longitudinal and transverse cracks and decline of evenness. The conventional surface repaving is usually not enough to keep the damaged road level in shape long.
The most valuable materials in road structure are quality mineral aggregates and bitumen. Particularly the upper part of the unbound bearing layer grinds in a long term by the effect of deformation due to loading and it is converted into highly hydrophilic, even frost suspectible. Considering the cost-effective maintenance and the lifetime of the structure it is most important to eliminate this problem by mixing the grinded layer with other materials.
NEW STATIONARY MIXING METHOD
Wearing courses have already for years been renovated by remixing equipment. The new working method has been developed out of this procedure. However, the normal pavement recycling equipment is not applicable.
The equipment has to be much heavier because it must be capable to process much heavier and bigger amounts of mixtures. The unbound layer under the surfacing shall be stabilized and in this way the problem caused by grinded material will be eliminated. The mixing depth of the process on the road shall be 15-20 cm.
A layer thicker than that must not be made in stabilization because of difficult or poor compaction. The total thickness of bound layers can be raised according to the design based on preliminary studies. If the old surfacing is very thick it is possible to make it thinner by milling and use milled asphalt for construction of new surfacing.
The old surface is first warmed up by radiating heaters. Even a minor rise in the temperature of the surface makes milling easier and improves the quality of the mixture; makes it easier to mix, lay and compact. Thus the method improves the quality of old binder in the recycling process, the mixture quality improves and the amount of new binder can be reduced.
USE OF REMIXER STABILIZATION IN FINLAND
The road structures of paved roads in Finland are mainly 20-30 years old. Financial cuts in road construction budgets during the 1970's and 1980's were made simply by reducing layer thicknesses. Now the negative consequences of the reduced layer thicknesses are beginning to come forth: loading durability on many roads is defective, and the fatigue of the road structure also reflects very strongly on the surface.
Pic. 7: Stabilization equipment at work on a road in Northern Finland.
The addition of mineral aggregates is usually quite small, just to correct longitudinal and edge indentations or to repair grading. When comparing results with the other stabilization methods, the mixture here has a very good quality and is extremely homogenous. The mixture is almost equivalent to the pavement and its quality is tested by applying pavement quality control. Mixing is comparable to mixing at the plant and heating of the mixture contributes considerably to good quality. About 2 million square meters of roads in Finland have been stabilized through this process.
When the work is performed almost entirely by using old materials, there is some variation between mixture proportions. But nevertheless the result of the work is excellent; e.g. dispersion values of binder content are only about twice as high as in the pavement masses mixed at the plant. A stabilized surface wears traffic well and immediately after compaction, traffic may drive on the stabilized structure. Surfacing can be layed immediately following.
Required loading durability is reached at thinner layer thickness than earlier which also saves materials. Besides observations in practice loading durability has been researched at the laboratory of road and traffic engineering in the Department of Building Technology in Oulu University.
Stabilization also enables the use of less qualified mineral aggregates, if quality of the materials is ensured by prequalification tests. According to one research, under a standardized test procedure, mineral aggregates of defective quality absorbed humidity 6-7 % and aggregates of good quality about 3 %. In the laboratory tests, it was observed that water absorption decreases in remixer stabilization so that stabilized mineral aggregate absorbs only 0.5-0.7 % water when bitumen content is even under 3 %. It is well-known that water, especially with its freezing and resolution phenomena in structures, is the worst and most critical point when considering loading durability .
DEVELOPMENT OF REMIXER STABILIZATION EQUIPMENT
To solve this problem the Lapland Road Region pavement unit began to discuss with the pavement contractor Savatie Ltd and equipment manufacturer Kalottikone Ltd some 7-8 years ago.
The first tests were performed by using the existing equipment, the surfacing remixer, heavier than normal. It was then stated that the work is possible, but for larger scale production the equipment is far too light. Since then the manufacturer has developed new equipment and constructed heavier machinery. Milling and mixing capacities have been greatly improved. Many other amendments have been developed which have an effect on mixture quality, layer thickness, road evenness and edge gradient.
The roles in the development work have been clear: Lapland Road Region has stated what the machinery should be capable to perform. Kalottikone Ltd as a machine workshop has constructed such machinery and Savatie Ltd, as a contractor, has made the stabilization work.
The method has been succesfully tested in Sweden and Norway as well.
For further information please contact:
Kalevi Luiro at the Lapland Road Region, tel.int. + 358 20444 3630,
fax int. + 358 20444 3672, or Jukka Karvonen at Kalottikone Ltd, tel. int. + 358 16 3680 111, fax int. 358 16 311 597.Mr. KALEVI LUIRO, Finnra and
Mr. JUKKA KARVONEN, Kalottikone Ltd
R&D Projects of Finnra's Traffic and Road Engineering Unit
ARCH. CODE
RESULTS OR CONTENTS OF THE STUDY
PROJECT NAMETIEL 2150007-97
Road project environmental impact assessment guideline
A revision of the 1992 Finnra environmental assessment impact guideline, taking into account experiences in 1990-96 and the Finnish EIA Act of 1994.TIEL 8000122E
Moving towards sustainabilty
Contains environmental development issues and the environmental policy of Finnra (in English).TIEL 3200410
Summary of the environmental surveys
As part of the Finnra public roads' environment survey, relations to nature protection, main roads of villages and small towns, and landscape and cultural heritage aspects were assessed. The summary also includes noise, exhaust emission and groundwater protection survey data.TIEL 3200367
Is car use reduction possible?
A study on the means to reduce car use and on people's attitudes to it.TIEL 3200379
Environmental impact indicators for the Road Administration activities
This report sets up the framework for environmental impact indicator development, to take place in 1997-99.TIEL 3200419
Car-free town? Studies on land use and transportation.
This is the third progress report of the Transport and Land Use project. The main theme of this report is how to reduce the role of the car in urban travel.TIEL 3200426
Sustainable development in regional development activity
This study aims at forming sustainable principles for the Road Administration input to future regional development.TIEL 3200457E
Valuation of impacts of road traffic emissions (summary in English)
This report reviews the bases and methods to determine the economic value of environmental impacts caused by road traffic fuel emissions, resuspension and noise.TIEL 3200461
Planning participation guidance
A guideline for developing public participation procedures in planning and design.TIEL 3200463
Road as an experience, construction and art
A study on how people respond to the road environment and new forms of environmental art, and the possibilities to use the idea of a "total work of art" as a road design principle.TIEL 3200467E
Traffic and land use (a Finnra strategical research and development project, in English)
This is the final summary report of the Traffic and Land Use project.TIEL 3200477
Germany and the Netherlands, working strategies to avoid traffic
An assessment of Dutch and German traffic system plans and policies to reduce car use.TIEL 4000131
Assessing the socio-economic impacts of road projects
A draft guideline for assessing socio-economic impacts in the road sector.TIEL 4000147
Impact of transport system efficiency improvement on exhaust emissions
An examination of how infrastructure improvements, traffic control and management influence exhaust emission levels.TIEL 4000148
Emission model for intersections
In this study, a model for calculation of traffic emissions at intersections was developed; to be included in the IVAR traffic investment assessment program.FinnContact is on the Internet at the web site address http://www.tiehallinto.fi/finncontact.htm.
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