Cambering

Cambering is the intentional introduction of curvature into a structural member or surface, typically to compensate for expected deflection or to facilitate drainage. In structural engineering, cambering is used to offset sagging that occurs when a beam or girder carries loads. By bending the member upward during fabrication (a precamber), engineers aim for a flatter or near-straight condition once it is in service.

In practice, cambering can be achieved by several methods. In steel and concrete construction, precambering may involve mechanical bending, temporary supports, or prestressing during production. After the cambering force is removed and the member is installed, service loads cause some downward deflection, which is balanced by the initial upward curvature. In timber and composite materials, cambering can be accomplished through steam bending, drying and shaping, or controlled curing processes. The goal is to arrive at the desired final geometry under expected loading conditions.

Cambering also refers to the cross-slope design of road surfaces, known as road camber or crown. A slight convex shape across the width helps drainage by directing water to edges or gutters. Typical camber values vary with traffic, climate, and substrate, but common road crowns range from a few millimeters to a couple of percent of the road width. The process involves shaping the subgrade and pavement layers during construction to maintain the intended drainage profile.

Overall, cambering is a design technique used to manage deformation and drainage by introducing controlled curvature into structures or surfaces. Its application depends on material properties, load assumptions, and construction methods.