Pavement

Pavement is the durable surface of a road, street, or other travel way that bears traffic and distributes loads to the underlying subgrade. In British usage, pavement can denote the sidewalk beside a street, while in American usage it usually refers to the traffic-bearing surface itself. In civil engineering, pavement also covers the wearing surface and the supporting layers beneath it.

Materials commonly used for pavement include asphalt concrete (hot-mix asphalt), Portland cement concrete, and, less frequently, paving stones or bricks. Flexible pavements use asphalt bound to graded aggregates; rigid pavements use poured concrete slabs. Design also considers drainage, friction, climate, and traffic loading, with base and subbase layers providing structural support.

Construction involves preparing the site, laying base and subbase, and installing the surface course. Asphalt is placed and compacted; concrete is cast in slabs with joints. Maintenance includes crack sealing, pothole repair, surface sealing, and resurfacing or recycling to extend service life.

Environmental and economic aspects include heat absorption, rainfall runoff, noise, and life-cycle costs. Reclaimed asphalt pavement (RAP) and asphalt recycling reduce material use. Permeable pavements can improve drainage but may require design trade-offs. Quality control during construction and ongoing maintenance are essential for durability.

History spans from cobblestones and macadam to the widespread use of asphalt and Portland cement by the mid-20th century. Ongoing research emphasizes durability, sustainability, and performance, guided by standards and specifications issued by national or international bodies.