Rheological properties of polymer-modified binders for use in rolled asphalt wearing course

A series of fundamental and empirical tests were performed on eleven binders and bituminous mixes with the same aggregate grading made with these binders. These consisted of three unmodified, seven laboratory-prepared modified and one proprietary modified bitumen. The results showed that the empirical binder tests, such as penetration and softening point, are deficient in predicting the performance of modified binders in asphalt mixes. The more fundamental dynamic tests are a better indicator of binder behaviour, but relationships need to be developed between the measured dynamic properties and asphalt mix performance. By comparing the binder and mixture properties, relationships are derived for modified binders in relation to deformation resistance. Deformation results from a full-scale road trial using modified binders are also presented to validate the laboratory testing programme. (A)