Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/85913
Hydrated lime is a low-cost, near-generic asphalt modifier that performs powerful tougher, and resistant to rutting, and may have other attributes as well asphalt mix stiffer, Hydrated lime also makes an anti-stripping functions. A monomer is a small molecule that binds chemically to other monomers to form a polymer, which is a large molecule made up of repeating structural units connected by covalent chemical bonds. The repeating unit of the hydrocarbon plastic polyethylene is an ethylene monomer Image credit: Y. Roiter and S. Minko 25 nm production of today's high-performance bituminous pavements, including Superpave performance-graded binders Asphalt modifiers are integral to Block copolymers unite performance of individual polymers into a single large molecule, consisting of multiple sequences, or blocks, of the same monomer alternating in series with other monomer blocks. For example the popular asphalt modifier styrene-butadiene-styrene (SBS) combines the strength of poly- styrene with the rubber-like flexibility of polybutadiene Image credit: Omnexus Polystyrene hard blocks Polybutadiene soft blocks Value-added asphalt modifiers such as Elvaloy RET (reactive elastomeric terpolymer) are said to help fight multiple major asphalt pavement failure mechanisms including rutting, stripping, cold cracking and fatigue cracking acetate (EVA), is the copolymer of Another popular asphalt modifier, ethylene vinyl materials in softness and flexibility, yet is tough and can be ethylene and vinyl acetate, which approaches elastomeric In the asphalt lab, modified asphalt binder samples are tested in the dynamic shear rheometer to determine performance characteristics that must be validated in the field processed like other thermoplastics Better Roads April 2012 17