ABSTRACT
Nowadays, cold bituminous mixtures produced with bitumen emulsion (CBEMs) represent one of the most attractive alternatives with respect to traditional hot mix asphalt. In particular, the use of CBEMs is increasing because they combine economical and environmental efficiency. CBEMs can be schematized as composite of coarse aggregate particles (virgin and/or reclaimed) covered and bound by a bituminous mastic (fresh bitumen and filler-sized particles), also incorporating part of the fine aggregate particles (sand). Therefore, the mechanical behavior of the whole CBEMs is strictly connected to the behavior of its associated Cold Bituminous mastic (CBm). The main objective of this study is to evaluate the effect of different mineral additions and volumetric concentrations on the LVE properties of CBms. Complex shear modulus (G*) was measured on CBms prepared with Calcium Carbonate (CC) or cement (CEM) at 0.15 and 0.3 as mineral addition ratios. In addition, the influence of curing time (1 and 3 days) on LVE properties, was also investigated. The testing protocol included Brookfield viscosity measurements during mixing phase and Complex shear modulus testing, performed at temperatures ranging from 5°C to 60°C. The results showed that CBm composition strongly affects the viscosity and the mechanical response of CBms. In particular, at higher temperatures and higher concentration ratios, phase separation was observed. The linear viscoelastic behavior showed an evolutive trend at longer curing times, especially for CBms prepared with cement.
