Influence of bitumen binder compounding on the properties of slurry surfacing

Abstract

The possibility of using compounded bituminous binders for the production of cationic bituminous emulsions, as a component in slurry surfacing mix, was investigated. Compounding was carried out by mixing a base 70/100 bitumen from PKN Orlen, produced from light crude oil, with 70/100 and 100/150 distilled bitumens from Nynas (Sweden), produced from heavy crude oil. Additionally, the base bitumen was mixed with pre-prepared acidic pitch (Hrybovychi, Lviv region). The study examined the properties of the acidic pitch and the main physical and mechanical characteristics of the compounded binders, including their acid numbers. For the production of cationic bituminous emulsions, both compounded and non-compounded binders were used for comparison. The composition of the bituminous emulsion also included a cationic emulsifier (amine-based), hydrochloric acid, and potable water. Emulsions were prepared using a laboratory bitumen–emulsion unit of the colloid mill type. Slurry surfacing mixtures were produced using emulsion binders, potable water, Portland cement grade PC II/A-Ш-400, and a breaking regulator in the form of a 10% wt. solution of the emulsifier used for the preparation of the cationic bituminous emulsions. The slurry surfacing mixtures were tested for mixture breakdown, material loss during wet abrasive wear, and cohesion strength parameters, specifically the onset of cohesion strength development, the express indicator of mixture formation, and the failure types NS and SS (allowing determination of transport opening with and without restrictions, respectively). The study demonstrated that effective compounding options include a ratio of distilled bitumen from heavy crude oil to bitumen from light crude oil of 50% wt. to 50% wt., and the addition of 10–15% wt. acidic pitch to the bitumen from light crude oil.