The polysulfide building sealant with no sag, high elongation and low modulus of the invention is a high elastomer similar to rubber after being completely cured. Mix proportion: main agent (a): curing agent (B)= 100: 10 (parts by mass, in standard state), which varies with seasons and regional temperatures. During the construction period, the dosage of curing agent can be adjusted, and the change range of component B is between 8- 12.
Third, the construction method:
1. Treatment of sealing surface:
Before construction, oil stains, attachments, dust and other sundries on the adhered surface should be removed to ensure that the adhered surface is dry and smooth and prevent poor adhesion.
2, filling the backing material:
According to the design requirements, fill the joints with gasket materials.
3, besmear brushs primer:
The design requires the use of primer, or the sealing of long-term soaking parts, and the primer needs to be coated on the adhered surface and dried to form a film.
4. Preparation of sealant:
According to the ratio given in the instructions, the two components are mixed evenly and can be used. Whether it is machine mixing or manual mixing, the color should be uniform without chromatic aberration. When mixing, bubbles should be prevented from mixing, and when gluing, bubbles should be prevented from mixing, and compacted and sealed.
Physical and mechanical performance index requirements of polysulfide rubber. Project technical control index 1 density g/cm3 specified value 0.1g/cm3 sag ≤3mm leveling smoothness 3 surface drying time ≤24h 4 applicability ≥2h 5 elastic recovery ≥70% 6 tensile modulus 23 C0.4 ≥ 0.6 or ≤ 0.6-20℃ > 0. 8. The constant elongation will not be destroyed after soaking; 9. Does not destroy the cohesiveness of cold drawing and hot pressing; 10. The adhesiveness will not be damaged after soaking and stretching-compression cycles; 1 1. Mass loss rate (%) ≤55. building technology
5. 1 Cleaning of sealing interface
Firstly, the 30*30mm foam strips reserved in the expansion joints of two adjacent box culverts are removed with steel brazing, and the sundries in and on the surface of concrete deformation joints are removed to remove dust and ensure the base surface to be dry. For honeycomb pitted surface and porous surface, use tools such as grinder and wire brush to polish the bonded surface to expose a solid structural layer. Blow the moisture on the dry-wet interface with a hair dryer.
5.2 Deformation joint treatment before gluing
1. The dust and residual slag in the deformation joint after the base treatment will be blown clean by the air compressor.
2. For the unsealed areas on both sides of the deformation joint, before construction, 20 ~ 30 mm wide protective tapes should be pasted on both sides 10mm to prevent redundant polysulfide glue from polluting the structural surface during construction.
3. Clean up the foundation surface, and notify the supervisor for acceptance after passing the self-inspection. The next step of construction can only be carried out after the acceptance.
5.3 sealant configuration process
1. Description of material configuration and primer use: This product is composed of component A and component B. When in use, component A (colorless and transparent) and component B (reddish brown) are evenly mixed according to the ratio of 1: 1, and then the primer is coated on the base surface of the deformation joint with a brush. After the primer surface on the base surface is dry, the primer can be painted. (Note: Before injecting glue, the primer on the surface of the base must be dry, otherwise it will seriously affect the bonding. This product is volatile, and the two components are packaged separately. The storage period under sealed conditions is one year, and the mixed primer is required to be used up at one time. )
2. Material configuration of two-component polysulfide adhesive
① Material ratio: Component A (white base slurry) is hereinafter referred to as A; A:B= 10: 1 Preparation (the manufacturer has repackaged it in proportion before leaving the factory, and there is no need to weigh it repeatedly on site).
(2) Glue mixing: open the lid of the A-component packaging barrel, add the B-component into the A-component packaging barrel, clamp the mixing tool with an electric hammer, first start the low-speed switch, stir for 3 minutes from top to bottom, then start the medium-speed switch, and stir for 5-8 minutes until the color of the glue is uniform, thus completing the preparation and glue mixing process.
5.4 gun loading process
1. Place the rubber pressure plate and push rod with glue outlet hole in the gun loader on the rubber mixing surface in the piston barrel.
2. Take the front and rear nuts of the gun barrel injected with glue, align the gun barrel mouth with the glue outlet in the middle of the glue pressing plate, push the gun barrel and the thrust rod, and press down hard. At this time, the glue is loaded upward into the barrel, and the air in the tube is discharged along the tail of the barrel until it is full.
3. Install the front and rear nuts filled with glue. At the same time, install a nut and a gun nozzle suitable for the width of the glue line. After the glue filling process is completed, you can inject glue.
5.5 Glue injection process
1. Insert the gun nozzle into the deformation joint to be sealed, inject the sealant into the deformation joint according to the designed depth and uniform density, and then scrape and shape it with a special shaping tool with radian. The formed joint surface is crescent-shaped, and the solidified colloid surface should be smooth, flat and bubble-free. The inside of the colloid should be kept dense, without broken ends, firmly bonded, without degumming, fracture and water seepage.
2. The curing time of the adhesive at room temperature (25 3℃) reaches the optimal strength of 7 days, and the destructive tests of air tightness, water tightness and oil tightness and various performance tests cannot be carried out within 7 days.
3. Because the deformation joint depth of this project is 3cm, it can be molded at one time when injecting glue.
5.6 Colloidal bonding technology in gluing process
If a deformation joint can't be injected with glue once, the following two methods are used for the second injection: dry joint and wet joint.
1. The time interval between two gluing operations shall not exceed 8 hours. Generally, wet connection is adopted. Wet connection has no special requirements for glue joint, and continuous glue application can be carried out.
2. When the time interval between two gluing operations may exceed 8 hours, dry bonding method should be adopted. Treatment method of dry connection colloid joint:
(1) At the end of the previous gluing, an inclined rough surface shall be left.
(2) When applying glue again, first apply a layer of glue on the inclined plane of the original glue joint by hand or scraper, and then carry out this glue application.
6, deformation joint sealant construction quality control
1. Inspection of sealant before use: The sealant colloid should be fine, bright, free of foreign matter and crusting. If necessary, the test section can be painted first for inspection.
2. After the deformation joint is finalized, the surface of the adhesive layer should be free of cracks and bubbles, smooth and full of glue, without degumming and glue leakage, and the color of the glue should be uniform.
3. The sealant and deformation joint are firmly bonded, and the bonding joint is neat and smooth, which meets the requirements. After curing, the hardness of the colloid meets the design requirements.
4. The key quality control procedures of sealant construction are as follows:
(1) The sealing interface of deformation joint must be surface treated with hand-held grinding wheel or steel brush, and treated with cutting machine if necessary, so as to ensure that the bonding interface is dry, clean, free of oil stain and dust, and the hard structural layer is exposed.
(2) The sealant should be fully mixed, and the two components should be mixed until the color is uniform.
(3) Before gluing, brush the primer on the gluing surface, then manually glue a layer, repeatedly squeeze, and then inject glue with an injection gun.
④ The mixed sealant should be used up within the required time, and the rubber compound beyond the adaptation period cannot be used together with the newly mixed sealant.
⑤ Colloidal lapping shall be carried out in strict accordance with the requirements of lapping process.
6. Glue coating engineering should pay attention to one direction, and the glue layer should be dense to avoid bubbles and glue shortage.
⑦ Before the rubber layer is completely vulcanized, attention should be paid to vulcanization, and flooding or artificial damage is not allowed.
⑧ Conduct technical disclosure before construction, and the construction ZuoYeDui requires a clear division of labor, earnestly implement it to everyone, and strengthen the education and implementation of the quality and responsibility of construction personnel.
7, construction safety requirements
1, construction personnel must be trained and qualified before they can take up their jobs, fully grasp the construction safety technology and quality standards that should be understood, and strengthen the awareness of safety and quality.
2. On-site construction personnel must wear flat-bottomed soft shoes, and are not allowed to wear leather shoes with roots, nails and hard soles, so as not to damage and affect the quality of the construction surface.
3, construction personnel should wear work clothes, take protective equipment (seat belts, helmets, protective glasses and protective gloves, etc. ) before the construction work.
4, around the construction site and homework, inflammable and explosive articles are not allowed to be stored.
5. Corresponding safety protection measures should be taken during the construction of sealant at the top of box culvert, and a safety officer should be set up to monitor it.
6, the site materials neatly, no littering, heap.
7. When mixing glue on site, no glue leakage is allowed. After the glue is mixed, it should be covered with protection to prevent dust from entering.
8, after the completion of the glue, to accidentally spilled sealant to clean up in time.
9. When the mobile operating platform moves, the operators on the platform must stand on the box culvert floor, and no one is allowed to move.