tarmaking

Tarmaking refers to the construction of paving surfaces using tarmac, a traditional term for road surfaces bound with tar or bitumen. In modern usage it generally means applying asphalt concrete to create durable roadways, runways, and other paved surfaces.

The term tarmac is derived from tarmacadam, a road surface developed in the 19th century by John Loudon McAdam and later improved by adding tar by Edgar Hooley in 1901. Today most tarmac is asphalt concrete rather than tar-bound; the word tarmac is still used colloquially for paved surfaces.

The primary materials are asphalt binder (bitumen) and aggregates such as crushed stone and sand. In early tarmaking tar was used; modern practice uses bitumen. Mix designs vary for different traffic conditions and climates; additions like polymer modifiers or recycled asphalt pavement (RAP) are common.

The typical process includes site preparation (subgrade, subbase), laying a base and wearing course, followed by compaction using pavers and rollers. Joints between runs are sealed; the surface is textured for skid resistance and allowed to cure before opening to traffic.

Techniques include hot-mix asphalt, warm-mix asphalt, porous asphalt, and micro-surfacing. Maintenance features include crack sealing, patching, and periodic resurfacing. Recycling of old pavement and environmental considerations are increasingly emphasized.

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