Gravity-filled mortar is a cement-based grouting material, which can meet the requirements of grouting only by filling by its own gravity during the pouring process. This product is used in the installation and fixation of wind (sound) barriers on many high-speed railways, passenger dedicated lines, such as Wuhan-Guangzhou Railway, Zhengxi Railway, Beijing-Shanghai High-speed Railway, etc., and has received good results. ,u0026nbsp;
1. Technical requirements
(1) Summer requirements for gravity-filled mortar
Serial number Item name technical requirements 1 machine flow (mm) ≥36030min fluidity retention value (mm) ≥3002 bleeding rate (%) 03 chloride ion content (%) ≤0.14 compressive strength (MPa) 2h≥201d≥4028d≥5051d vertical expansion rate (%) ≥0.02628d contraction Rate (%)≤0.17 Frost resistance (g/m2) No abnormal appearance, peeling amount≤1000
(2) Gravity-filled mortar winter requirements< br/>
serial number project name technical requirements 1 Primary fluidity (mm)≥34020mm Fluidity retention value (mm)≥3002 Bleeding rate (%) 03 Chloride ion content (%)≤0.14 Compressive strength (MPa) 2h≥54h≥201d≥4028d≥5051d Vertical Expansion rate (%) ≥0.02628d shrinkage rate (%) ≤0.17 Frost resistance (g/m2) No abnormal appearance, peeling amount ≤1000
Second, construction method
(1) Preparation before construction
1. Gravity filled mortar The construction organization design and construction technical plan should be formulated before grouting.
2. Gravity filling mortar before grouting You should prepare metering equipment, mixers, grouting equipment, templates, and maintenance items.
3. Gravity filling mortar when pouring The template support should be firm. The template can be a plastic composite template or a rigid template, and a water-permeable template cloth can be affixed in the template.
4. Before the construction of the gravity-filled mortar, the surface of the concrete foundation in contact with the gravity-filled mortar should be cleaned Clean, free of debris, gravel, floating slurry, floating ash, oil and other debris. u0026nbsp;
(2) Stirring
1. When mixing the gravity-filled mortar, use special metering equipment to add water according to the required water consumption of the product, and it is not advisable to increase its fluidity by increasing the water consumption.
2. Gravity filling mortar should be mechanically stirred on site. Use a hand-held electric stirrer for stirring, and the stirring speed should not be lower than 700r/min. Add the mortar first, then add the mixing water, the mixing time should not be less than 2min. u0026nbsp;
(three) perfusionu0026nbsp;
1. Stir evenly and gravity-fill the mortar slurry, place it for 1-2 minutes, wait for the bubbles in it to disappear, and then start pouring.
2. Gravity filling mortar from pouring When pouring the holes, use a funnel for pouring or pouring from the gap of the template. The height of the funnel should not be less than 400mm; when pouring from the side, the height of the template should exceed the bottom surface of the steel plate by 5-10mm.
3. Gravity filling mortar when grouting The mortar entering temperature should be controlled at 5-30℃;
4. When the gravity filling mortar is poured, the surrounding structures should be protected to prevent the leakage of the mortar from polluting the environment.
5. Gravity filling mortar for summer construction In addition to the performance of the gravity filling mortar which should meet the technical requirements, the following measures should be taken:
(1) Cooling measures should be taken for the foundation surface before the gravity filling mortar is poured;
(2) Cooling measures should be taken to fill the mortar and water by gravity to ensure that the temperature of the mortar is below 30℃ during pouring;
(3) After the gravity filling mortar is poured, it should be Take timely moisturizing and maintenance measures to prevent the surface from cracking due to rapid loss of water.
6. During winter construction, except The performance of gravity filling mortar should meet the technical requirements, and the following measures should be taken:
(1) Gravity-filled mortar should be mixed with hot water, the temperature of the mixing water should not be higher than 60℃, and the temperature of the slurry entering the mold should not be lower than 5℃; When hot water is mixed, you need to explain to our company in advance;
(2) Before freezing, the compressive strength of gravity-filled mortar shall not be less than 10MPa. u0026nbsp;
(4) Maintenance and demoulding
1. After the gravity-filled mortar is poured, heat preservation and moisturizing should be applied to the exposed part in time, and the unexposed part should be cured with a mold. If it cannot be cured with a mold, please explain to our company in advance; or Cover in time after removing the mold to avoid surface cracks caused by excessive water loss on the surface.
2. Under negative temperature conditions, Do not use water to maintain the poured gravity-filled mortar;
3. When the gravity-filled mortar is demolded, the temperature difference between the mortar core and the environment shall not exceed 15℃. u0026nbsp;
Three, packaging and storage
(一)Packaging
Gravity-filled mortar is packed in bags, and the net content of each bag is 50kg.
(two) storage
The dry storage shelf life of gravity-filled mortar is six months.
