Asphalt concrete

**Asphalt Concrete Mixtures:**
– Hot-mix asphalt concrete (HMA) involves heating asphalt binder and aggregate.
– Warm-mix asphalt concrete (WMA) uses additives to lower mixing temperatures.
– Cold-mix asphalt concrete is made by emulsifying asphalt in water.
– Cut-back asphalt concrete is produced by dissolving asphalt binder in kerosene.
– Mastic asphalt concrete is created by heating bitumen and adding aggregate.

**Performance Characteristics of Asphalt Concrete:**
– Varying surface durability and tire wear among different types of asphalt concrete.
– Lower roadway noise compared to Portland cement concrete.
– Easier drainage due to asphalt’s viscosity.
– Concrete’s higher durability but potential need for specific drainage methods.
– Common use on high-traffic pavements due to performance advantages.

**Specialty Asphalt Mixtures:**
– Stone-matrix asphalt for a strong wearing surface.
– Porous asphalt pavements for water drainage.
– High-modulus asphalt concrete for high fatigue resistance.
– Additives like polymers and antistripping agents for improved properties.
– Specialty mixtures tailored to specific application needs.

**History, Development, and Applications:**
– Asphalt mixtures used in pavement construction since the early 20th century.
– Various terms like asphaltic concrete and bituminous mixture in engineering.
– Common applications on roads, parking lots, airports, and environmental uses.
– Development of specialty mixtures to meet specific requirements.
– Use in embankment dams and as liners for landfills and reservoirs.

**Recycling and Sustainability in Asphalt Concrete:**
– Reclaimed asphalt pavement (RAP) as the most recycled material in the U.S.
– Incorporation of roofing shingles and other recycled materials in asphalt mixes.
– Processing methods for RAP and RAS, including recycling in asphalt plants.
– Performance considerations and challenges in using recycled components.
– Exploration of new waste materials and rejuvenators for sustainable asphalt construction.https://en.wikipedia.org/wiki/Asphalt_concrete