Panaudotų padangų gumos taikymas asfalto mišinių ir bitumo modifikavimui

Abstract

Increasing number of vehicles generates millions of end-of-life tyres each year. According to the European Tyre & Rubber Manufacturers’ Association (ETRMA) shows that more than 3 million tons of used tyres are collected and treated each year and it means that 95% of all arisings of end-of-life tyres are collected. In Lithuania more than 30 000 tons of end-of-life tyres are collected each year. In Lithuania 8% of collected end-of-life tyres are burned in cement kilns, 33% recycled, 15% treated or stored, 39% exported and the usage of 5% is unknown. Crumb rubber from end-of-life can be used for asphalt mixtures in the two main ways – wet method (bitumen modification) and dry method (asphalt mixture modification before bitumen incorporation). Results of researches gives contradictory conclusions, in some cases crumb rubber improves performance of asphalt mixtures, in other cases properties are decreased. It mainly depends on mixture type, bitumen amount, crumb rubber particle size and amount, design procedure. Actually, there is relatively low number of researches carried out with dry process, which means it is still unclear what amount of rubber is desirable and how crumb rubber effects asphalts mixture properties. In Lithuania there is recommended to conduct laboratory researches to determine the most suitable conditions for bitumen and asphalt mixture modification with crumb rubber, construct and monitor test fields to receive the actual crumb rubber modified asphalt mixture performance in such severe climate conditions.