Causes of Movement
Types of movement
All buildings are subjected to forces which cause them to move. Since the materials of a building do not have sufficient strength to absorb these movements, the building is divided into smaller independent structures. This limits the stress on any one part of the building.
It is this movement that expansion Joints and Movement Control Joints are designed to absorb. Types of movement can be divided into cyclical and noncyclical. Cyclical forces include temperature and atmospheric moisture changes. Non-cyclical forces include shrinkage, subsidence creep and seismic movement. The principal causes of movement and their effects are shown below.
At low temperature the above structure will show deformation.
At high temperature the above structure will show deformation