PROPERTIES OF MASTICS USING DIFFERENT FILLERS WITH BOTH UNMODIFIED AND EVA-MODIFIED BINDERS

The properties of mastics are fundamental to the performance of many types of hot mix in current use. Whilst some fillers appear chemically inert in mastics, others are considered as chemically active. The way these different types of filler affect mastics and mixes was investigated. Limestone and hydrated lime fillers were incorporated into two binders - 100 penetration paving grade and an EVA polymer modified binder based on the same bitumen. The resultant mastics were assessed using several test procedures, on the bitumen, on the mastics and some on hot mix samples. The tests included rheology, Cantabro and net adsorption. The effect of short-term ageing of the binder was also investigated. The results showed the greatest effect was due to filler volume concentration whilst the short-term ageing caused substantially less change. With the materials studied, there was no evidence of significant hardening due to a chemical reaction between the active filler and the polymer modified binder. For the covering abstract see ITRD E121480.