Laboratory Assessment of Low Temperature Resistance of High Modulus Asphalt Concrete in Relation to Climatic Conditions in Poland

Abstract

The paper presents the assessment of the properties of high modulus asphalt concrete in low service temperature range. Such an assessment is particularly important due to the climatic conditions of Poland and the problem of the occurrence of thermal cracking in recent years. The scope of laboratory tests included both resistance to low temperature cracking according to TSRST method, but also other methods to characterize its strength properties and behaviour at low temperature. The indirect tensile strength characteristics and the thermal expansion coefficients were investigated. The analysis of the results included both the comparison of different mixtures, as well as the analysis of the probability of occurrence of pavement cracks, taking into account the minimum temperature in the layer defined on the basis of climatic data. Two mixture types were chosen for analysis: conventional asphalt concrete and High Modulus Asphalt Concrete. Either of them contained different bitumen types, including standard pen-grade bitumens, polymer-modified binders (PMB) and so-called highly-modified binders.