LOW-TEMPERATURE CRACKING OF POLYMER-MODIFIED ASPHALT

A laboratory investigation was conducted to study different types of p olymer-modified asphalt with regard to low temperature behaviour. The thermal stress restrained specimen test (TSRST) was used to assess the disposition of asphalt mixtures to cracking at low temperature. Five polymer modified bitumens and three mixture types (dense graded, stone mastic and porous asphalt) were investigated. In addition, three diff erent ''gussasphalt'' mixtures were analysed. Based on the results obt ained, it was concluded, among other things, that (1) the polymer type , mixture type and degree of ageing influence the low temperature prop erties of asphalt mixtures; (2) the increase in fracture temperature d uring ageing is dependent on mixture and polymer type; (3) the use of modified binders may improve the low temperature properties of ''gussa sphalt'' mixtures.