Biljana Vuksanović, B.Sc .( C.E .)

Biljana Vuksanović, B.Sc.(C.E.) USE OF ELECTRO-FILTERED ASH AND CLINKERPRODUCED IN THERMO-ELECTRIC POWER PLANT “NIKOLA TESLA А andB” AND THERMO-ELECTRIC POWER PLANT“КOSTOLACА and B” FOR THE NEEDS OF ROAD CONSTRUCTIONresearch-developing project EMPLOYER : PUBLIC ENTERPRISE “ROADS OF SERBIA”PREPARED BY : THE HIGHWAY INSTITUTE May 2008, Divčibare

30-40 million of tons of lignite is used in the Republic of Serbia annually • 7-8 million of tons of electro-filtered ash is produced • only 1-2% is used in the cement industry • Electro-filtered ash is disposed at 1400 hectare of fertile land • Estimated value of stockpiled ash is 300 million tons • The greatest producers of energy out of lignite are • Thermo-electric power plant “Nikola Tesla" A and B • Thermo-electric power plant “Kostolac" А and B May 09, 2008, Divčibare

May 09, 2008, Divčibare

Projectgoals: • collection, analysis and synthesisof all previous laboratory data, • laboratory tests for key samples of electro-filtered ash and clinker from the on-going production of thermo-electric power plants • laboratory tests for samples of ash mixed with lime or cement, in accordance with our technical standards for road construction materials and European standards • Comparison of the results and assessment of the quality and applying possibility of electro-filtered ash and clinker • Analysis of harmful effects of electro-filtered ash and clinker to the environment • Proposal of possible technical and technological solutions for ash and clinker use in road construction • economicjustification and specification of advantages of electro-filtered ash and clinker use in construction and maintenance of road beds and superstructures and other road surfaces in Serbia in comparison to classic road construction materials (gravel, send, crushed stone etc.). May 09, 2008, Divčibare

PERFORMED TESTS • chemical • physical-chemical • physical • Mineralogical • content of radio-nuclides • pozzolanic attributes • physical-mechanical • For content of heavy metals • For content of other harmful ingredients May 09, 2008, Divčibare

RESULTS AND RECOMMENDATIONS • Based on physical-mechanical characteristics, chemical content of ahs and clinker, as well as composites attained by combining them with lime and cement, performed tests have undoubtedly shown that these materials are convenient for road construction. • The project indicated that placement in road base should be done in segments isolated from the effects of surface and underground water, and some characteristic cases have been treated in this way May 09, 2008, Divčibare

ASH APPLIANCE Embankments made purely of electro-filtered ash May 09, 2008, Divčibare

embankments with ash and geotextile embankments with ash and binders – lime or cement This type of embankment is more applicable in urban areas, where it is necessary to occupy as less as possible land during construction. These embankments can be of steeper grad than 1:1.5 May 09, 2008, Divčibare

embankments in specific geotechnical conditions Problems of low bearing capacity of stratum or high level of underground water. These parameters determine specific conditions for construction of embankments. May 09, 2008, Divčibare

Infilling behind the object Backfilling of infrastructural elements May 09, 2008, Divčibare

CONSLUSIONS • Electro-filtered ash and clinker are the most common waste – secondary material in the Republic of Serbia • Dumps of electro-filtered ash and clinker, although under constant surveillance and monitoring,cause significant disturbance of environment: • In the following period primary goal for all relevant institutions in the Republic of Serbia should be production of electro-filtered ash and clinker as secondary waste and secondary raw material. • Research-developing project is valorization of waste material, electro-filtered ash and clinker into secondary raw material – road construction material. • Results and tests show that electro-filtered ash and clinker have changeable mineral, chemical, physical and mechanical characteristics, which originate from non-homogeneous composition of coal burnt in thermo-electric power plants. • Electro-filtered ash and clinker have pozzolanic characteristics • Content of radionuclide is bellow the limits of radioactive contamination, set for construction material; May 09, 2008, Divčibare

Physical – mechanical characteristics of ash and stabilized ash with addition of cement and lime from thermo-electric power plants “Obrenovac” and “Kostolac” are in the range of values that verify this material as adequate for construction of roads and other infrastructural (elements of) systems (embankments, infillings of ditches, infillings behind objects etc.). • Electro-filtered ash and clinker should be placed in road base in segments, isolated from the impact of surface and underground waters, since in that way, during the road exploitation, syringe of chemically harmful elements from ash and clinker and their penetration into waterare disabled. • Completed analysis of expenditures for construction of embankments with pure electro-filtered ash and ash with 2% of lime at terrain with good and low bearing capacity, where height of embankment is 3 and 8 m, compared to the expenditures of construction with common dusty-clayey and sandy – gritty materials, shows that construction of embankment from ash per m3, depending on type of embankment, is for 30 – 80% cheaper. • Based on the achieved results of research-developing project, it can be said that use of electro-filtered ash and clinker in road construction is possible under the conditions defined in this project. • Results of research-developing project indicate the possibility of ash and clinker usage in construction of pavement road-base, but additional tests are needed. May 09, 2008, Divčibare

Biljana Vuksanović, B.Sc .( C.E .)

Biljana Vuksanović, B.Sc .( C.E .)

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