Investigation of the dynamics of permanent deformations for the AC 11 asphalt mixtures

• Published in: Rīgas Tehniskās universitātes zinātniskie raksti. 2. Sērija, Arhitektūra un būvzinātne Arhitektūra un būvzinātne, 2008-01, Vol.9, p.37-44
• Main Authors: Haritonovs, V, Smirnovs, J, Naudt'uns, J
• Format: Article
• Language: eng ; lav
• ISSN: 1407-7329

Up to now, the system securing asphalt quality in Latvia includes only the Marshall test, which anticipates the conventional deformation indicator - determination of strain stability and flowability with the constant compression rate of 50mm/min at the temperature of 60 deg C. There is lack of standard methods in Latvia, which in the laboratory circumstances could provide manufacturing and loading of asphalt specimens similar to real circumstances. Large role in predicting the asphalt deformation features is played by the load application speed, impact duration and application frequency. The research has been made by using the standard performance test method - the Wheel Tracking test. Four compositions of asphalt mixtures have been used in the experiment - AC11/Lim (with the dolomite aggregate), AC-11/D (the diabase aggregate), AC-11/Gr (the granite aggregate) and the AC-11/Ref reference mixture made of the martin steel slag. The B70/100 unmodified bitumen binding agent has been used for all the investigated mixtures. The results have shown poor strain stability of the conventional mixture -AC-11 with dolomite, granite and diabase, under the heavy transport load, in comparison with the AC11/Ref reference mixture. The results of investigating the rutting dynamics under the intensive heavy transport load, by using the VESYS method, have shown that the allowed rut depth 25mm is reached already during the first year of the asphalt pavement usage.