Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
258658 | Construction and Building Materials | 2012 | 5 Pages |
In the present work a laboratory evaluation of the low-temperature rheological properties of neat and polyphosphoric acid (PPA) modified bitumens by using a Dynamic Mechanical Analyzer (DMA) is presented. Fundamental rheological properties were evaluated in controlled kinematic conditions and the results obtained were compared with traditional procedures such as the Fraass breaking point. The results show that the effect of polyphosphoric acid addition at low temperature is strongly dependent on bitumen composition (i.e. wax and asphaltene content), nevertheless it seems that PPA is able to decrease the glass transition temperature (Tg) and to increase the stiffness, improving the low temperature performance of the modified materials.
► The effects of polyphosphoric acid (PPA) on bitumens from different sources were investigated. ► Dynamic Mechanical Analysis (DMA) at low temperatures was adopted. ► PPA shifts, towards lower values, the bitumen glass transition. ► PPA seems to improve low temperature bitumen behavior. ► Experimental results suggest the existence of an optimal PPA concentration.