CNST 202 ch3

CNST 202 ch3 - CNST 202 2-12-08 Chapter 3 - Asphalt Asphalt...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CNST 202 2-12-08 Chapter 3 - Asphalt Asphalt - Sources Natural deposits of asphalt occur within porous rock, called “rock asphalt” “Bitumen” is a mixture of hydrocarbons that comprises “asphaltic cement” as a by- product of oil refining Virtually all asphalt in the US is produced by petroleum refineries Properties of asphalt Strong cement that is readily adhesive Highly waterproof and durable Plastic and imparts controllable flexibility Highly resistant to most alkalis, acids and salts Uses for asphalt Paving - highways, streets, driveways and parking lots Roofs Tennis courts, walkways and bike paths Joint sealer Curbs and roadway shoulders Pond lining Mix types Cold-laid - mixture is spread and compacted at atmospheric temperatures, used for temporary repairs of pavements Hot-laid - mixture is spread and compacted at elevated temperature, with both aggregate an asphalt heated prior to mixing Asphalt for paving Paving asphalt is highly viscous - adheres readily to aggregate particles and is excellent cement Aggregate portion of the mix carries the compressive load Asphalt resists the tension stresses Aggregates comprise 90-96% of the weight, and 65-85% of the volume Asphalt recycling Asphalt generally has lower removal and replacement costs due to common practices of recycling old pavements Recycling done either by “cold milling” or ripping-and-crushing
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

CNST 202 ch3 - CNST 202 2-12-08 Chapter 3 - Asphalt Asphalt...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online