1. Introduction to Bridge Waterproofing Construction
Bridge deck waterproofing construction refers to the construction process in which a series of technical measures and material applications are used to prevent rainwater, snow water, and other moisture from infiltrating the bridge deck, thereby protecting the bridge structure from damage. The main purpose of bridge deck waterproofing construction is to extend the service life of the bridge and ensure its safety and durability.
2. The Importance of Bridge Waterproofing Construction
Bridge deck waterproofing is one of the key factors for the durability of road and bridge construction projects. If the waterproof system of the bridge deck fails, moisture will seep into the bridge body, causing damage to the concrete structure, thereby affecting the traffic capacity and safety of the bridge, and even causing serious economic losses.
3. Technical points for bridge deck waterproofing construction
(1) Cleaning the base layer: Before construction, the bridge deck base layer must be thoroughly cleaned to remove oil stains, impurities, gravel, dust, etc., to ensure a clean and tidy surface. This can be achieved through shot blasting to improve the bonding strength between the waterproof coating and the base layer.
(2) Dealing with expansion joints: Expansion joints are the parts of bridge structures that are prone to water leakage. Polymer modified asphalt elastomers are usually used to fill expansion joints to solve the problem of water leakage.
(3) Waterproofing treatment of lower structure: The lower structure is prone to contact with water and requires the use of waterproof concrete and waterproof coating to improve waterproofing requirements and avoid erosion.
(4) Winter construction: When carrying out bridge deck waterproofing construction in winter, it is necessary to choose sunny weather with high temperature and do a good job of insulation to prevent poor film formation or cracking caused by low temperature during film formation.
4. Specific steps and technical requirements for bridge deck waterproofing construction
(1) Spraying waterproofing agent on cement concrete surface: First, spray waterproofing agent on the concrete surface, usually with two coats of spraying.
(2) Spraying bridge deck waterproof coating: After spraying the waterproof agent, spray the bridge deck waterproof coating again, usually two to four times, with an average coating thickness of no more than 2mm.
(3) Requirements for adhesion and durability: The waterproof layer should have good adhesion and durability, be able to adapt to the characteristics of dynamic load compression and tensile resistance of elevated bridges, and still meet the waterproof requirements when the concrete bridge deck cracks ≤ 2mm.
(4) Environmental adaptability: The waterproof layer should still meet durability requirements under environmental conditions ranging from -15 ℃ to+90 ℃, and should not affect its long-term use after being subjected to asphalt layer paving temperature of about 160 ℃.
