The Function of Expansion Joints:

In building structures, expansion joints are designed to minimize the impact of temperature changes on the foundation, such as those embedded in the soil beneath the wall or column foundations, or in strip or box foundations, as these are less susceptible to temperature-induced deformation. This results in greater restraint on the lower part of the superstructure compared to the upper part, potentially leading to cracks in the upper structure when temperatures fluctuate. The installation of expansion joints ensures that the main load-bearing components are not damaged by temperature stresses. In bridge structures, expansion joints prevent excessive additional stresses from developing in statically indeterminate structures due to temperature stresses, which can lead to structural damage. In large-scale concrete construction, the placement of expansion joints can control cracking in the concrete. In summary, expansion joints are set at locations with lower loads to mitigate the adverse effects of temperature stresses. For more information, please contact Lian Guan Building Materials.

Settlement joints are installed to prevent uneven ground settlement from causing cracks or damage to the upper structure. For instance, in situations where there is a significant difference in floor heights, uneven soil conditions, or the connection between new and old buildings, settlement joints are generally required. Settlement joints need to break the foundation, whereas expansion joints can remain unbroken; therefore, settlement joints can also serve as expansion joints.

3. Seismic joints are designed to prevent severe damage caused by uneven vibration frequencies and deformations in earthquake conditions due to differing stiffness between the upper parts of two structures. They should be installed in complex floor plans, buildings with significant height differences, and structures with greatly varied stiffness. The seismic joints must have sufficient width; otherwise, they may lead to collisions between the two parts of the building due to different vibration periods and phase angles, resulting in more severe consequences.