Dolomito skaldos panaudojimas asfalto viršutinio sluoksnio mišiniams

Abstract

Dolomito skalda yra viena iš Lietuvos naudingųjų iškasenų, naudojamų kelių tiesybos sektoriuje: gaminant asfalto mišinius, įrengiant automobilių kelių skaldos pagrindo sluoksnį, asfalto paviršiaus apdarą, gaminant geležinkelio balastą, gelžbetonio konstrukcijas, statybinį betoną, akmens vatą, trąšas ir stiklą.

Depending on asphalt purpose various type of aggregates arc used for its production in Lithuania. Dolomite aggregates are often used lor asphalt binder layer, base and base-wearing layers. In Lithuania and foreign countries aggregates with high resistance to tragmentation and polishing are selected for asphalt wearing layer of heavy duty pavement. In Lithuania, granite aggregates are often used for asphalt wearing layer, but this magmatic rock is imported from other countries. Dolomite is one of the most available sedimentary rocks in Lithuania, hither, high strength dolomite is produced applying special extraction technology, therefore the mechanical properties of this material are similar to granite. The aim of this research is to design rut resistant asphalt mix with dolomite aggregates. The research was made in 2015 at Vilnius Gediminas Technical University Road Research Institute. Two type of asphalt mix were designed (asphalt concrete AC It VS and stone mastic asphalt) using granite and high strength dolomite aggregates. These asphalt mixtures were designed based on fundamental properties ip accordance to standard LN 13108-1. Resistance to permanent deformation (rutting)- is achieved by high content of air voids (3-4%) and optimized granulär composition. The research shows that positive influence to resistance to permanent deformation could be achieved by optimizing quantity of binder and granular composition of aggregates. Asphalt concrete mix AC 11 VS with high strength dolomite aggregates could be used for the 2nd and lower asphalt pavement class wearing layer. The use of stone mastic asphalt mix SMA IT S with high, strength dolomite aggregates for asphalt wearing layer should be evaluated additionally, taking into account the change of physicalrand mechanical properties of high strength dolomite aggregates during road maintenance.