TESTING OF PHYSICAL-MECHANICAL PROPERTIES OF COARSE AGGREGATE, USED FOR PRODUCING ASPHALT MIXTURES, AND ANALYSIS OF TEST RESULTS

1094 TESTING OF PHYSICAL-MECHANICAL PROPERTIES OF COARSE AGGREGATE, USED FOR PRODUCING ASPHALT MIXTURES, AND ANALYSIS OF TEST RESULTS Matas Bulevi ius 1 , Kazys Petkevi ius 2 , Daiva Žilionien 3 , Karina Drozdova 4 1 SE “Problematika”, Galves str. 2, LT-2028 Vilnius, Lithuania. E-mail: [email protected] 2, 3 Dept of Roads, Vilnius Gediminas technical university, Saul tekio ave. 11, LT-10223 Vilnius, Lithuania. E-mails: 2 [email protected]; 3 [email protected] 4 SJSC Latvian State Roads, Road laboratory, Gogola str. 3, LV-1050 Riga, Latvia. E-mail: [email protected] Abstract. In Lithuania investigation of various physical-mechanical properties of aggregate by using test methods of EU standards was started already in 2004. A lot of tests were carried out for different type of aggregates of different manufacturers to determine resistance of aggregate to freezing and thawing (F value) according to EN 1367-1, resistance to fragmentation (SZ and LA values) according to EN 1097-2 and the polished stone value PSV according to EN 1097-8. Taking into consideration aggregates, available in Lithuania and used in road building, the suitability tests and requirements for their properties were described. Based on the tests of rocks of the same origin and on the analysis of results obtained the relationship between F, LA, SZ and PSV physical and mechanical values was identified. When investigating aggregates used in road building the suitability of each test method was assessed for Lithuanian climatic conditions. It was determined that the assessment of aggregate suitability by use of freezing and thawing test is not suitable to Lithuanian climatic conditions. Investigated aggregates are suitable not only for asphalt concrete pavement and road pavement structure base layers, but can be used to transport construction, and building on the foundations of watertight clay soils in place if there are of good filtration. Keywords: aggregates, physical properties, asphalt pavement, strength, asphalt mixtures, resistance to freezing and thawing, fragmentation, polished stone value. Introduction Defects of road pavement caused by the impact of heavy vehicles influence functionality of road pavement, driving comfort and traffic safety. In order to improve the properties of road pavement and the quality of traffic the scientists of Lithuania and various countries carry out investigations of structural pavement layers, analyze the effect of their properties on pavement performance, mechanical and physical properties of asphalt mixtures used for structural pavement layers, etc. Aggregates (crushed stone, dolomite, gravel) differ in their size, shape and working conditions of the material which depend on the size and nature of loads, working temperature, environ- mental aggressiveness, etc. The aggregate can be affected by static, dynamic, permanent, variable or cyclic loads. The temperature of working environment can be low or high, and the environment itself – neutral or agressive. Mechanical and physical properties of aggregate, used for producing asphalt mixture, influence the quality indices of pavement structure, i.e. functionality, reliability and durability. Aggregate suitability to asphalt mixtures is dependent on its mechanical and physical properties. Aggregate properties determine the mode of production of asphalt mixture, the thickness of structural pavement layers and other peculiarities of road pavement structure. Thus, when selecting aggregate the working conditions (loads, environment, operating requirements) of road pavement structure shall be analyzed and the aggregate selected shall the best correspond to performance parame- ters. In each case selection of aggregate shall be eco- nomically justified. The selected aggregate shall be cheap and easily available. When a stronger aggregate is used the service life of road pavement structure is longer, the structure is more reliable, the individual structural pavement layers are more thin, the costs of aggregate and other materials are lower, etc. Often the aggregate is selected not because of its better properties but because it is cheaper. Therefore, a special attention should be given to the selection of components of asphalt mixture, i.e. to carry out comprehensive investigations of all components of asphalt mixture and the quality (suitability) control of the