Base wetting
(1) Before plastering the surface layer, water and wet the base layer first, brush the cement slurry bonding layer with water cement ratio of 0.4 ~ 0.5 the next day, and then plaster the surface layer. If the cement slurry bonding layer is painted too early, it can neither bond with the base layer nor with the surface layer, but it will cause the ground to be empty. Therefore, it is necessary to insist on using a brush.
Laying method
(2) The paving method of the ground is to spread mortar between standard bars, pat them with a wooden trowel while paving, scrape them off with a short wooden pole according to the elevation of standard bars, and scrape them from indoors to the door, which is consistent with the elevation of the door frame kerf line. Then use a wooden trowel to flatten it, and use a steel trowel to press 1 time. It should be lightly pressed to make the smear line shallow, and it is advisable that no waterline appears on the surface after calendering.
If there is excess water on the surface, a layer of dry cement or dry lime sand can be evenly sprinkled according to the water quantity to absorb the excess water on the surface, and then compacted and calendered. However, pay special attention. If there is no excess water on the surface, don't sprinkle cement at will, otherwise it will cause the surface layer to crack.
Mortar initial setting
(3) When the initial setting of cement mortar begins, it can be pressed for the second time with a steel trowel, and it should be compacted and calendered, and there can be no pressure leakage. The second calendering is the most important, and the surface should be cleared of bubbles and pores, so as to be flat and smooth.
(4) Before the final set of cement mortar, wipe it with an iron trowel for the third time. When plastering, use a little force to flatten, compact and polish the plastering lines and capillary holes left in the second time.
Suitable for local conditions
(5) When the ground area is large and meets the design requirements, mark the position of the grid line on the wall or skirting board according to the position and size of the ground grid line, and mark the grid line on the wall or skirting board after leveling the mortar on the surface;
First, use a wooden trowel to rub out a surface layer about the width of a trowel, then use an iron trowel to smooth it, then gently press it, then use a chalk line bag to play on the grid line, and use a ground grid separator to draw a grid seam along the line close to the guiding rule. Before the final setting of the surface cement, use a steel trowel to flatten and calender, and evenly divide the grid joints.
quality assurance
(6) The cement floor should be calendered three times to survive. We should correctly grasp the time of plastering each time to ensure the engineering quality.
Calendering too early or too late will cause the quality problems of sand and ash falling on the ground.
Extended data:
Curing condition
After plastering the surface of cement mortar, it should be cured under normal temperature and humid conditions.
(1) maintenance should be timely. Watering too early is easy to peel off, and watering too late is easy to produce cracks or sand. Generally, it shall be maintained after 24 h in summer and 48h in spring and autumn, and the maintenance time shall be no less than 7 d, and it is best to spread sawdust before water conservation. When watering, spray water with a watering can to keep the sawdust moist.
(2) If slag portland cement is used, the curing time should be extended to14 d.
(3) During the curing period, the strength of cement mortar surface is less than 5 before. OMPA, you are not allowed to walk or do other operations on it to avoid damaging the ground.
At present, Beijing, Xi, Shenyang and other places use curing spirit to maintain cement floors. Cement floor curing agent is an inorganic polymer water-based coating, which can be brushed by brush row, roller brush and roller coating, or directly sprayed by guniting or air jet. Mainly used for newly plastered cement mortar and pisolite concrete floor.
Because of its osmotic solidification and premature dehydration, cement floor forms a dense and hard surface layer on its surface, which plays a role in curing and hardening; When used for adding sand to old cement ground, it can also improve the surface hardness.
Compared with traditional curing methods (watering, spreading grass curtains or silver powder), it can save 60Kg/ m2 of curing water, improve work efficiency by 3-4 times, increase rebound strength by 20-40%, and improve wear resistance by 50%, which is beneficial to fire prevention and hygiene in construction site.
Starting from 1986, Liaoning, Hebei and other places have developed it for the maintenance of cast-in-place concrete walls, and achieved good results.
Precautions:
Special attention should be paid to the following points during spraying construction:
① The curing agent is a viscous liquid with a specific gravity greater than 1.30. When it is used, it should be diluted with clean tap water to the specific gravity of 1. 16.
(2) The curing liquid is strongly alkaline, so care should be taken not to touch skin and clothes during operation, and protective clothing should be worn when spraying in windy weather outdoors.
Eyepiece.
(3) Indoor and outdoor, such as metal, glass, paint, ceramic tile and other decorative materials or finishes, must be strictly protected.
(4) Spray brush tools should be cleaned immediately after use.
⑤ When other decorative materials need to be made, they should be sprayed for 7 days.
⑤ Solidified alcohol should be stored in plastic barrels. If it is frozen below -5℃ in winter, it should be thawed by water bath heating, and then used after stirring.
Mix thoroughly before use.
(1) should be sealed when stored, and it can still be used after filtering if there is a small amount of sediment.
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