Expansion joints, also known as shrinkage joints, are constructional seams strategically placed along the appropriate sections of buildings or structures to prevent cracking or damage due to climatic temperature changes (expansion from heat and contraction from cold). These joints divide the building components above the foundation, such as walls, floors, and roofs (excluding wooden roofs), into two independent sections, allowing the structure to horizontally expand or contract along its length.

Building expansion joints allow buildings to expand horizontally along their length, suitable for rooftops and above buildings. Types G: QF-C, GQF-Z, GQF-E, etc., other expansion joints are also known as temperature joints. Discipline 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, completely separating 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, so no separation is necessary. The width of expansion joints is generally 2 to 3 centimeters, filled with insulation material, and the spacing between two expansion joints is clearly specified in the building structural codes.

If the building's plan dimensions are too long, due to thermal expansion and contraction, it may result in excessive temperature stress within the structure. Therefore, a gap needs to be set at certain lengths within the structure to divide the building into several sections, 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.

Type Bridge Expansion Joints: GQF-C, GQF-Z, GQF-E, GQF-F, and GQF-MZL models, all are bridge expansion joint products designed with extruded steel profiles. The GQF-C, GQF-Z, GQF-L, and GQF-F expansion joints are suitable for bridges with expansion less than 80mm, while the GQF-MZL expansion joint model consists of side beams, middle beams, cross beams, and linkage mechanisms, suitable for bridges with expansion ranging from 80mm to 1200mm in medium and large spans.

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 across the bridge.

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

(2) Durable and reliable

(3) Vehicles should pass smoothly without abrupt jumps or noises

(4) Waterproofing and prevention of debris infiltration and blockage

(5) Installation, inspection, maintenance, and debris removal should all be simple and convenient.