LIFE+ 09/ENV/EE/227
Maanteeamet Eesti Energia Nordecon Ramboll Skepast&Puhkim

In November 2016 with the submission of the last reports the OSAMAT project was officially finished. After 5 years of pilot activities with oil shale ash (OSA) in road construction field, it could be stated that the project results have been successfully achieved and OSA is a competitive material on the construction market. The technical monitoring first years’ results after Narva -Mustajõe and Simuna-Vaiatu pilot sites construction showed that OSA is suitable for the construction. The application of OSA doesn’t also have environmental impacts according to the environmental monitoring data. Thus OSA use in road construction (instead or partly instead of cement) helps to reduce the natural resources extraction for the cement production and collateral environmental impacts, including CO2 emissions to the atmosphere. Undoubtedly the environmental risks connected to OSA landfilling on the ash plateau will be decreased with OSA usage increase.

OSA was already used in road construction in Estonia some decades ago. Past experience had provided a certain confidence in successfulness of the OSAMAT project when planned the project. A lot of people asked why a new project should have been initiated while Estonians had already had the previous experience of OSA use in road construction. The OSAMAT project was necessary for many reasons. Firstly the construction methods and technologies were changed. Mass-stabilisation technology that was tested at Simuna-Vaiatu pilot site is new for Estonia. However, other countries’ experience and the results of the OSAMAT project show the effectiveness of the method in stabilisation of soft soils, including peat stabilisation.   Secondly, the new combustion technologies blocks (circulated fluidized bed) were installed at Narva power plants. The ash of the new combustion blocks has other properties comparing to the ash generated in the old, pulverized firing blocks. Also some filters in old pulverized firing blocks were changed, that also influenced the ash quality. So, by the project initiation we had had at least 2 new types of the ash which properties should have been explored and tested. Thirdly, with entering the European Union and environmental legislation modifications the environmental impact studies became an integral part of the project to be sure in the absence of impacts to the environment and human health.

Experience and data received during 5 years work, formed the basis for the practical guideline “European Guideline for Practice” work out. The guideline gives instructions to a constructor about the way OSA should be used in stabilisation of upper road layer and mass-stabilisation of peat. The guideline can be down loaded from the webpage chapter “Documents/Technical documentation/Guidline for European Practice.

Due to OSAMAT project, OSA is going to be used in construction of Tallinn-Tartu highway and Rail Baltic railway construction. Besides Estonian project, the biggest Scandinavian ports are interested in OSA usage: Kokkola (Finland), Gothenburg (Sweden) and others. In ports OSA is used for stabilisation of contaminated sea sediments.

Although the OSAMAT project has been officially finished, the project activities are still continuing. In the years 2018 and 2020 the technical and environmental monitoring of pilot sites are planned to conduct. Therefore, any modifications in pilot constructions with the time will be followed. More information about post-project activities could be found “Documents/Dissemination Materials/After-LIFE Communication Plan.

Any other project information (years Progress Report, booklets, monitoring reports and others) could be found in the webpage chapter “Documents”.

The International OSAMAT Conference and Workshop were held in Tallinn on 2 and 3 of June 2016. More than 100 participant and media representatives took part in the Conference.

The objectives of the events were to deliver the OSAMAT project results and in particularly:

-        to present the oil shale ash ina new perspective: as material for road construction (based on the project results),
-        to provide technical information about road construction with OSA on a example of the pilot sites construction (Narva-Mustajõe and Simuna-Vaiatu pilot sites), quality control and monitoring,
-        to present pilot sites environmental monitoring results and discuss on environmental issues,
-        to open discussion about OSA further standardisation and conformation as a product
-        to foster international networking and present experiences from Finland, Germany and Greek.

The first day of the conference was targeted to the wide auditorium: politician, transport authorities, road managers, contactors and scientists. Firstly, the general information about the OSAMAT project and the project activities and results were presented. Then the floor was given to Estonian Road Administration and Ministry of Environment to get an assessment of the project actions and support in further steps to legalise OSA use in road construction. Finally, the experience of Finish, Germany and Greek experts in utilisation of by-products in road construction were presented and discussed. 

The conference ended with the panel discussion. It was emphasized the value of the experience and data received during the OSAMAT project, as the need for “carbon free” materials is growing with the growing demand of binder material in general. The expert from Finland brought an example of Helsinki city: every year million tons of sub-soil is generated. Instead of landfilling it might be stabilised with environmentally friendly materials as OSA and give environmental and economic savings for all the parties.

The aim of the second day of the conference aimed to foster the communication between interested parties: Eesti Energia as a producer of oil shale ash and authorities, contractors and scientists as a consumers of the material. The program included the visiting of the Narva-Mustajõe pilot site and discussions at the place and a Workshop where the practical issues as OSA production volumes, storage and loading capacities, transportation, legal status of OSA and new developments were discussed. Additionally LIFE program opportunities were presented by the representative of Ministry of Environment at the Workshop.

As an output of the Workshop and conference in general EE:

-        continues collaboration with the biggest construction company who has an experience in mass-stabilisation in other countries and who gives us a great help in promoting OSA and mass-stabilisation in Estonia,
-        continues collaboration with Finnish company who research the binder production in an alternative way.
-        takes part in international project RECIPE (HORIZON 2020 program), where 
            o   the new approach in transportation of OSA will be tested,
            o   OSA will be tested in stabilisation of port contaminated sediments
o   OSA will be tested for conformation to European standards

2 of June 2016 the OSAMAT International Conference 2016 “Management of Environmentally Sound Recycling of Oil Shale Ashes into Road Construction Demonstration in Estonia” will be held in Tallinn.

The Conference will deliver the results of the OSAMAT project, including:

·         Presentation of oil shale ash from a new perspective, as a material for road construction
·         Road construction with oil shale ash: technical information about constructing pilot sites Narva-Mustajõe and Simuna-Vaiatu, quality control and monitoring
·         Environmental safety regarding using oil shale ash: presentation of the laboratory research and pilot sites monitoring
·         Legislation
·         Fostering international networking, presentation of the experience from Finland, Germany, Greek and Sweden

The Conference will be held at the KUMU museum in Tallinn, Weizenbergi 34/ Valge 1 on June 2nd, 2016.

The language of the conference is English.

You can register to the conference sending your name and occupation to the e-mail katrin.ressar@energia.ee.

You can see the program here.
Press release

The results of the pilot sections Narva-Mustajõe and Simuna-Vaiatu construction, built with oil shale ash produced in the Narva Power Plants of Eesti Energia, confirmed that oil shale ash is suitable for use in the construction of roads.

The technical and environmental monitoring surveys, conducted as a part of the pilot project between 2012 and 2016, revealed that both of the test sections constructed with oil shale ash have high strength and road-bearing capacity parameters. There was no decomposition of the constructed layers emerged during the monitoring period on both test sections as well as no negative environmental impacts have been noticed.

“The pilot project confirmed that oil shale ash has good stabilising and binding properties and can be therefore successfully used in substituiton of cement,” said Margus Vals, Member of the Management Board of Eesti Energia.

In the first stage of the project, the ash was used in the construction of the stabilising layer beneath the asphalt on a 1.6-kilometre section of Narva-Mustajõe road. In the second stage, 900-metre section was constructed in Simuna-Vaiatu road. The oil shale ash was used in mass-stabilisation of the peat layer.

“Oil shale ash has been used successfully in road construction in Estonia before, and these roads have proven to be durable. In the frames of the pilot project the oil shale ash was for the first time tested in modern mass-stabilisation technology. The possible impacts on the environment were also checked. As the results are promising, in the next step we are going to standardize the ash as a product. This will enable the larger quantities of the product to be used in base layer stabilisation and mass-stabilisation in Estonia and abroad. In this way we can add more value to oil shale by offering a quality product at a competitive price to road constructors and reducing the use of non-renewable materials in the construction of roads and ports,” added Vals.

Narva-Mustajõe and Simuna-Vaiatu pilot sections were built within the framework of the OSAMAT (Management of Environmentally Sound Recycling of Oil Shale Ashes into Road Construction Products) project, aiming to facilitate the wider use of oil shale ash generated during production of electricity. According to Taavi Tõnts, Lead Engineer in the Road Network Development Department of the Estonian Road Administration, the OSAMAT project can, in general, be regarded as successful. “Based on the research and tests conducted, we now know that it is technically possible to use oil shale ash also from fluidised bed boilers for mass-stabilisation, in addition to cement. For example, along the new section of the Tallinn-Tartu-Võru-Luhamaa Highway, we have already had planners who consider the mass-stabilisation as one of the alternatives for crossing peat bogs in their comparative technical economic analyses. On roads with lower traffic volumes, we are planning to approve the use of weak stone material (coming from oil shale enrichment) in complex stabilisation. Due to such researches we have a possibility now to use energy production by-products in road construction. Economic efficiency should be assesed separately in the case of each project,” said Tõnts.

The pilot project has been carrying out between 2010 and 2016. The parties of the project are Eesti Energia, Nordecon, Ramboll and the Estonian Road Administration. The cost of the project is EUR 2.4 million and it is supported by the European Union programme LIFE+ for the co-funding of environmental projects. Oil shale ash has been used in road construction before, between 1971–1986 in Estonia, Latvia, Lithuania, Belarus and Russia. In this period more than 1000 kilometres of roads were constructed with oil shale ash. The ash was also widely used for the reinforcement of embankments when the impovements in crushed stone quality and other fillers were needed.

The monitoring reports “Technical monitoring and scientific of data from OSAMAT project pilot sections” and “OSAMAT – post-project environmental monitoring” are available under "Documents"
Second phase of Simuna-Vaiatu test section construction works were completed in August 2014. Works included levelling of base layers, removal of preload layer from mass stablised part, layer stabilisation with 100 % oil shale ash on 500 m section and complex stabilisation by traditional method – by cement and bitumen - on another 500 m section.

The following phases were surface dressing, road marking, cleaning of ditches, grass seeding and covering of slopes.

Hereby it would be appropriate to give a short summary about technical and environmental monitoring of Simuna-Vaiatu section, prior to construction works of this year.

In 2013 settlement plates were installed on top of mass stabilised layer in order to measure sinking of peat and receive information when to build upper pavement layers. The Consultant performed 4 measurement series in 5 locations:

  • Reference heights were fixed after completion of mass stabilisation works;
  • First measurement took place 1 week up to 1 month after completion of works;
  • Second measurement took place 3-5 months after completion of works;
  • The last measurement took place in June 2014.

The results indicated major sinking during autumn 2013 and further slowing or even stopping of the process. The Finnish experience also confirms that the main sinking takes place during the first 6 months after completion of mass stabilisation works.

We also performed cone penetration and vane share tests with the objective of measuring unity and homogeneity of stabilised peat soil – i.e. whether sufficient amount of binder had been used and it had spreaded evenly. Field works took place in November 2013 and July 2014.

Minimum sample limit value is 50 kP and the results of the first measurement were in the range of 50-160 kPa (2-3 months after mass stabilisation) and the second measurement 60 - >200 kPa. Cyclone ash has the highest indicator. The results indicate that mass stabilisation works were successful.

The Consultant has performed environmental monitoring of Simuna-Vaiatu section with the analysis of water, soil and flora properties in order to assess possible environmental impacts accompanying the use of oil shale ash. Water and soil samples were taken before commencement of construction works and flora was inspected in the road vicinity. New soil samples and a water sample were taken next to road section after a month after completion of mass stabilisation works. No changes of water environment and flora in comparison with the background were detected in both cases. The last additional water sample will be taken and flora inspection will be performed this autumn.

We have finalized OSAMAT project video, where it is possible to see overall background and goals of the project and also overview of main activities with preliminary results.

Environment Day Seminar of Eesti Energia was held on 4th of September at Vaivara county in Auvere. The seminar focused this time on by-products of the oil shale industry. At the Environment Day the main subject was oil shale ash and as one of the latest pilot projects about oil shale ash innovative usage in Estonia – OSAMAT project – was introduced, its main goals and first results. Aleksander Pototski, Manager of Eesti Energia Narva power plant oil shale ash sales department, made ​​a presentation about OSAMAT projects and he pointed out that the initial results show, that the binders with oil shale ash work well in layer stabilisation and give positive results. "Reached load bearing parameters are sufficient for the road construction according to Estonian law," said Pototski. At the event also OSAMAT project short film was presented to the public, the film is introducing the mass-stabilisation principles and works at Simuna-Vaiatu pilot site.

The main idea, which came out trough different presentations at Eesti Energia Environment Day was that, although a number of oil shale industries by-products are in terms of legislation defined as waste, they can often be seen rather as products or as raw materials, which can be used to the maximum extent, only if there are good ways how to use them.

More detailed information about Eesti Energia Environment Day is available at the companies’ blog in Estonian here:


Short film about mass-stabilisation principles and works at Simuna-Vaiatu pilot site can be found from projects webpage under news section.

Information Day was held in Väike-Maarja on 6th of August, where LIFE + project OSAMAT Simuna-Vaiatu test section works were introduced to the members of Asphalt Pavement Association.

In the seminar, which took place in Väike-Maarja, Arina Koroljova (EE Narva Power Plants AS) introduced OSAMAT project in general, Marjo Ronkainen (Ramboll) introduced various recipes used in Simuna-Vaiatu test section, formulations and quality control activities and Ville Niutanen (Biomaa Oy) gave an overview of the mass-stabilization technology, which is used at the test section as well as elsewhere in the world.

After the presentation, all participants had an opportunity to visit a Simuna Vaiatu test section, and ask questions from the project parties about the technology and the use of materials.

This year starting from in mid-July, LIFE + project OSAMAT second test section construction in Simuna-Vaiatu 3,0-4,0 begun. The first phase of the work will be completed by September, and the whole section is finished in June 2014.

Pilot project second section tests mass stabilisation in peat and other unstable soil using oil shale in 500 meters long road section. Every 100-meter section will be built with a different substance prescription, varying ash-cement proportions. Pilot section construction tests cyclone ash, dust incineration ash, fluidized bed boiler ash.

After the construction works sections are monitored for few years to in order to obtain information about the various sections of ash mixes stabilized behavior. According the current plan road sections monitoring at least until year 2016.

LIFE + project OSAMAT first test section in the national road No. 12109 Narva-Mustajõe 14,0 to 16,1 km was ready at the end of 2012. First part of the test section was built in the autumn of 2011, and the second part in October 2012th.

The binders used in mass stabilisation are komposiittsement, binder mixtures of oil shale ash from electricfilter block 3 and 8 total of approximately 500 tons. Oil shale ash was used to carry out the existing base layer stabilisation. In addition to it approximately 4,700 tons of oil shale mining waste rock was used in the construction. New road surface was constructed and the road water flow system was repaired. During the construction binders were tested regularly to see that it is in accordance with laboratory receipts. For two years after the construction site monitoring and measurements will be conducted, during which ash stabilized layer properties and durability will be tested.

Images of the object construction can be viewed in the gallery.

Technical reports can be accessed through a link on the documents.

This project has been funded with a contribution from the LIFE financial instrument of the European Community