tar macadam

A worker spreads tar macadam on a new road.

Definition

Noun:
- A paving material: "tar macadam" is a type of road surfacing material made by mixing crushed stone (macadam) with tar, which acts as a binder. It was commonly used for roads and pavements before the widespread adoption of asphalt.
- Example: The old highway was surfaced with tar macadam, giving it a dark, durable finish. (The road was covered with a mixture of crushed stone and tar for strength.)

Usage Examples

• (The driveway used crushed stone bound with tar for durability.)
• (This material was widely used in less developed areas due to its cost-effectiveness.)

Advanced Usage

• "Tar macadam vs. asphalt": Tar macadam is a specific predecessor to modern asphalt; while asphalt uses bitumen (a petroleum product), tar macadam uses coal tar. The term is sometimes used interchangeably with "tarmac," though "tarmac" is a trademarked brand name.
  • Historically, tar macadam was preferred for its ability to bind stone tightly, but it was later replaced due to environmental concerns. (The material was effective but less common today.)

Variants and Related Words

• Tarmac (n): a shortened, informal term for "tar macadam," often used for airport runways or roads.
  • The plane landed on the tarmac. (The aircraft touched down on the paved runway surface.)
• Macadam (n): the crushed stone base used in tar macadam, without the tar binder.
  • The road was built with a layer of macadam before the tar was applied. (The stone layer was laid first for stability.)

Synonyms

• Pavement: a general term for a hard, durable surface for roads.
• Asphalt: a similar material using bitumen instead of tar (modern equivalent).

Related Idioms

• "Hit the tarmac": to land or arrive on a paved surface, often used informally for traveling.
  • After a long flight, the passengers hit the tarmac. (They stepped onto the airport runway or pavement.)