Due to the construction of expansion joint waterproofing is hemp wire, asphalt plaster grouting treatment, due to waterproof aging, shrinkage, cracking, foundation settlement coefficient inconsistency and other factors lead to leakage phenomenon, seriously affect the normal use of the building.
Analysis of leakage causes
- Basic reasons: The foundation treatment is not fully considered, so the settlement coefficient is not consistent, resulting in high and low sides of the expansion joint.
- Design reasons: The expansion joint waterproof design is too simple, resulting in failure to meet the expansion requirements.
- Waterproof sealing material selection: Waterproof sealing material was ordinary sealing paste, anti-aging, low expansion performance, resulting in waterproof layer aging and cracking.
The project leakage management program
According to the functional requirements of the project, structural characteristics, we follow the requirements of the technical specifications of waterproofing, the project to take “Multi-channel fortification”, “Composite waterproofing”, “Node seal” And other measures, selected varieties of waterproofing materials, to determine the construction and node practices, and put forward corresponding technical measures program.
Waterproofing materials selection
- 50 × 50 mm water expansion waterstop (the implementation of gb/t18173.3-2002 standard) the product has a flexible seam waterstop material sealing waterproof function, when the side distance between the two sides of the seam to increase the elastic waterproof material elastic recovery rate outside, due to the material has the characteristics of water expansion, in the material within the expansion range can still play a role in waterstopping, expansion body still has a rubber nature, more water-resistant, acid-resistant, alkali-resistant. It is widely used for construction joints, expansion joints and cracks of underground railways, tunnels and concrete projects.
- The two-component polyurethane sealant (jc482-92 standard) is composed of component a containing nco and component b containing curing agent, reinforcing agent, tackifier and filling material. The product is mixed according to the specified proportion, and after cross-linking reaction, it will be solidified into a sealing material with rich elasticity, strength and strong adhesion. The product is mainly used for building settlement joints, expansion joints, construction joints, airport runways, bridges and other joint parts of the seal.
Construction technology
Corridor expansion joints
- Basic requirements: Use the cut partition machine will be 50cm on both sides of the expansion joints cut open (to prevent damage to the adjacent marble when hitting burin), and then will cut partition and expansion joints between the marble and mortar layer off, until the grass-roots level (concrete slab surface) clean up.
- Will be expansion joints on both sides of 10cm wide hit “V” Shape mold dropping depth of 5cm.
- Level both sides of the “V” Shape with cement mortar.
- Use 50×50cm water-swelling water-stopper on the bottom of the expansion joint.
- Seal and compact the water stop strip with two-component polyurethane sealing paste.
- Laying yhj-10.1 epdm waterproofing roll-roofing material
(1). Grass-roots cleaning. Level the raised surface of the base layer, and clean the dust and debris thoroughly.
(2). Apply grass-roots treatment agent. Use brush method to paint the grass-roots level, the paint should be uniform.
(3). Apply the grass-roots adhesive. Before using the base adhesive, stir well before use, respectively, in the grass-roots and coil bottom surface. Brush should be uniform, do not miss the bottom, do not accumulate.
(4). Laying coil. Gluing about 20 minutes, basic non-stick hand, with hand pressure side by side in addition to drive air, bonding should be used again after roller rolling again, bonding solid not wing, not drum, and then sealed with polyurethane sealant.
- After 24 hours of water testing, do waterproof protection layer.
- Paving marble with 1:2 of cement mortar paving about 20 mm, then the marble was horizontal shape cover, to take lightly, do not let sharp objects scratch the surface, and use hand light pressure or with rubber hammer gently knocking marble, be sure to make it smooth, and with the ground bonding strong, do not appear gap, or by people step on easy to fracture. Paving at any time with cotton silk and other soft cloth will seam in the extruded slurry wipe clean. After laying, you can regularly find wax on the board surface to ensure its shiny shine.
- Finally, use polyurethane sealing paste to irrigate the joints.
Floor expansion joints
- Grass-roots level requires 50cm on each side of the expansion joint with a cut partition machine (to prevent damage to the adjacent floor tiles when hitting the burin), and then the floor tiles and mortar layer between the cut partition and the expansion joint should be dropped until the grass-roots level (concrete floor surface) is clean.
- Laying floor tiles
(1). Soak the tiles for an hour before laying to prevent cracking, and take care to put the same type and size of tiles in the same area when laying.
(2). Construction to clean up the ground, if the ground is not severely hollowed out, you can proceed to spring line construction.
(3). In the construction plane to pull out the diagonal to find out the center, and then according to the design pattern, with cement mortar (cement and sand ratio of 1:2) to do adhesive from the center to all around lay flat, with hand lightly pressed or rubber hammer gently knocked, and the ground sticky.
(4). When laying, the floor tiles and the ground must be completely filled with cement between, no gap. Otherwise, after the cement is dry, people step on it and it is easy to break.
Quality requirements
Material: 50 × 50mm water expansion stop, epdm rubber waterproofing membrane, two-component polyurethane sealant must provide inspection reports, instructions for use, only after the party’s approval.
Finished product protection measures
The protection of the finished product of the waterproofing layer is very important, and targeted protective measures must be developed during construction, and non-waterproofing construction personnel must not enter.
