Expansion joints, also known as expansion seams, are construction joints placed at appropriate locations along the construction缝 direction of buildings or structures to prevent cracks or damage to structural components due to climatic temperature changes (expansion due to heat and contraction due to cold). These joints divide building components above the foundation, such as walls, floors, and roofs (excluding wooden roofs), into two independent sections, allowing for horizontal expansion along the length of the building or structure.

Building expansion joints allow for horizontal expansion along the length of the structure, suitable for rooftops and above buildings. Type G: QF-C, GQF-Z, GQF-E, etc., other expansion joints are also known as temperature joints. Subject classification: Architecture, Application field: Building Science.

One: The primary function is to prevent cracks in buildings due to climatic changes. The method involves leaving gaps at certain intervals along the length of the building, disconnecting all above-ground components such as the roof, walls, and floors from the building foundation, which is buried underground and thus less affected by temperature changes and does not need to be disconnected. The width of expansion joints is generally 2 to 3 centimeters, filled with insulating material, and the spacing between two expansion joints is strictly specified in the building structural codes.

If the building's plan dimensions are too long, due to thermal expansion and contraction, it may cause excessive temperature stresses within the structure. Therefore, a gap should be set at certain lengths within the structure to divide the building into several parts, and this gap is known as a temperature joint. The distance between expansion joints varies depending on the structural system. Article 8.1 of the current Chinese standard "Code for Design of Concrete Structures" GB50010-2010 specifies this specifically.

GQF-C, GQF-Z, GQF-E, GQF-F, and GQF-MZL types of bridge expansion joints are all designed with hot-rolled, integral-shaped, special-shaped steel. The GQF-C, GQF-Z, GQF-L, and GQF-F expansion joints are suitable for bridges with expansion of 80mm or less. The GQF-MZL expansion joint consists of side beams, middle beams, cross beams, and a linkage mechanism, and is designed for medium to large span bridges with expansion ranging from 80mm to 1200mm.

To meet the requirements for bridge deck deformation, it is typically done between the ends of the two beams, between the beam ends and the bridge abutment, or on the bridge itself.

Section 3: Structural Requirements (1) Free expansion and contraction in both directions parallel and perpendicular to the bridge's axis.

(2) Durable and reliable

(3) The vehicle should run smoothly without sudden jumps or noises.

(4) Waterproofing and Prevention of Debris Penetration and Obstruction

(5) Installation, inspection, maintenance, and dirt removal should be easy and convenient.