New test for rutting evaluated

A new Multiple Stress Creep Recovery Test (MSCRT) has been introduced as a fast and user-friendly bitumen specification test for rutting. A Nynas study analysed whether this MSCRT relates to rutting and how the test can identify the presence of a polymer network in a bituminous binder.

A new Multiple Stress Creep Recovery Test (MSCRT) has been introduced as a fast and user-friendly bitumen specification test for rutting. A Nynas study analysed whether this MSCRT relates to rutting and how the test can identify the presence of a polymer network in a bituminous binder.

The MSCRT, a good binder test to predict rutting resistance?

The multiple stress creep recovery test (MSCRT) was recently introduced, as a quick and user-friendly test to evaluate the rutting resistance of bituminous binders.  This test can be performed by most commercially available rheometers, and it can be applied to modified as well as unmodified binders.  In this test, several loading-unloading cycles are applied to the specimen: initially the sample is loaded 10 times at a low stress of 100Pa, where each cycle consists of 1s loading followed by 9s unloading.  After these first ten cycles, ten more cycles are applied at a higher stress of 3200Pa. 

The purpose of this study is to evaluate the responses of various binders, unmodified and modified.  It is shown how the response curves differ for various binders.  In addition to the repeated creep recovery tests, standard oscillation measurements were also conducted.  In a second part of the paper, several binder test results were compared to the rutting resistance of the corresponding mixes, which were measured in a wheel tracking device.

Authors

Hilde Soenen, Marianne De Keyser, Geert Lemoine, Serge Heyrman from Nynas