Wall pathology
Introduction
The walls of a building that have a structural function are called bearing wall or bearing wall; that is, those that support other structural elements") of the building, such as arches, vaults, beams or joists of floors or the roof "Roof (construction)").
When walls support the pressures of the adjacent ground, they are called retaining walls. When they support horizontal loads from the same construction, for example from vaults or arches, they are called buttresses.
History
Although many types of load-bearing walls were built in ancient times, the oldest surviving ones are made of adobe or stone. There is evidence of the existence of pastes and mortars "Mortar (construction)") precursors of concrete since the times of Ancient Egypt,[1] but it was the Romans who promoted this material with the Emplectum technique, consisting of creating two outer sheets of stone ashlars, filled with a lime mortar with sand and rubble.[2] This construction technique has been repeated with slight variations (such as the Dacian wall), throughout history.
In places where stone was scarce or excessively expensive to obtain, it was replaced by clay in the form of adobe: a sun-dried mud brick. Likewise, a parallel can be established between the emplectum and the rammed earth, a form of construction consisting of imprisoning mud between two plates or wooden formworks, and compacting it in successive tongadas using mallets or tampers. Once a course of rammed earth was finished, the formwork was placed on top, and the operation was repeated. With these mud and adobe techniques, buildings of up to six heights were erected, some of which survive in Yemen.
But the material most used to make load-bearing walls is brick: an evolution of adobe whose difference lies in the firing process, which gives it greater resistance and durability. The brick used in load-bearing walls is usually solid, although it is not unusual to find perforated or even hollow brick load-bearing walls in one- or two-story homes.
A variant of the brick load-bearing wall is that made with concrete block, although it is not possible to reach great heights by this method.
As in previous times, there is also a reflection of the Roman emplectum in the current use of mass concrete, where, as happened in the rammed earth, the concrete is confined by formwork until it sets and acquires hardness.