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Keep the cement slab moist to prevent exposure to the sun and freeze.
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Cement mortar plastering should be watered and cured to avoid cracking, which is scientific and must be done.
After the cement mortar is plastered, the water needs to be volatilized and lost during the drying process, especially in the summer when the temperature is high, the water loss will be faster. In the case of rapid water loss of cement mortar, it is easy to cause cracking, so it is necessary to drench water in order to make the cement mortar not dry so quickly, so as not to cause cracking.
Cementitious material is a hydraulic material, which must go through a sufficient hydration process to make the strength of the cement reach the ideal value, and after drying, the hydration process of cement will be terminated. In layman's terms, if the hydration of cement takes 8 days to reach the ideal value, but it dries out in 2 days, the hydration process is terminated, and its strength will be particularly lost. Therefore, the timely watering of the cement every day is also to keep the hydration process of the cement continuing.
Therefore, there are two functions of water curing: one is to prevent cracking, and the other is to ensure that the hydration of cement is sufficient to complete the strength formation of cement.
Of course, the method of watering is a general folk construction process. If it's a project, it's tiring to die of water every day and you can't accurately grasp it, so what should you do? Special mortar will be used, that is, different admixtures should be added to the cement mortar to make the cement mortar have some different special functions.
In the special mortar, if you want to solve the above problems, you need to add hydroxypropyl methyl cellulose, which is called a water-retaining agent in the industry, after adding it, the drying time of the cement mortar is controlled, and there is no need to be watered every day for maintenance.
According to the difference in season and temperature, the full hardening of cement, that is, the curing molding period is generally 28 days in principle, but there is a large difference in the actual project, the specific curing period should be determined according to the structure type, cross-sectional size, concrete number, cement variety, etc., combined with temperature, humidity, evaporation, curing process and other conditions, but in summer, the general ordinary concrete curing 15 days of strength is enough to achieve, and sometimes in winter, such as concrete pavement sometimes poor conditions and even maintenance for two months are difficult to achieve sufficient strength, However, no matter what concrete and what maintenance conditions, the first 7 days must ensure that the coating is thermal insulation and moisturizing curing, and the structure with strict maintenance conditions can be cured with heated water or even pressure water.
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After the prefabricated concrete floor slab is made, it can be covered with a layer of plastic film and then watered for curing. Generally, after 7 days, it can be put away.
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Hello, dear. We'll be happy to answer for you. Maintenance Method:
There are two methods of curing cement floors: natural curing and steam curing, and natural curing is usually used. 2. Curing process:
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Cover with moisturizing film, felt, cloth, straw curtain, etc. Water is sprinkled on the mulch and the ground is wet-cured. In this way, the cement floor can meet the requirements.
The thickness of the film should be considered for the curing of the plastic film, and the width of the plastic film should be greater than the width of the ground, preferably more than 60 cm. Cover both sides with mud to prevent moisture loss. Finally, it is important to note that the lap width between the membranes should be greater than 40 cm.
When the polymer cement waterproof mortar does not reach the hardened state, it shall not be watered and cured or directly washed by rainwater, and the curing method of alternating dry and wet shall be adopted after hardening; In a humid environment, it can be maintained under natural conditions.
In the maintenance, the potholes on the road that seriously affect driving safety must be quickly repaired, even if temporary emergency measures are adopted, driving safety must be ensured. Cracks are allowed on the road surface, and cracks are filled with cracks, but there are potholes on the road surface that are not allowed to pass normally, which endangers driving safety.
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The timing of the start of concrete curing depends on the local climatic conditions and the type of cement used in the concrete project. For the curing of ordinary cement varieties in the general environment, the curing should start after 12 to 18 hours after the concrete is poured. The curing time should last 21 to 28 days.
Concrete curing generally adopts several methods such as sprinkling natural curing, spraying film curing and plastic film wrapping curing. The mechanism of these concrete curing is to keep the concrete moist and avoid water loss to achieve the purpose of curing.
During the curing of concrete, the humidity and temperature control of concrete should be strengthened, the exposure time of surface concrete should be minimized, and the exposed surface of concrete should be closely covered in time, which can be covered with tarpaulin, plastic sheeting, etc., to prevent surface moisture evaporation. Before the initial setting of the concrete of the protective layer of the exposed surface, the covering should be rolled up, and the surface should be rubbed with a trowel at least twice to make it smooth and covered again, and it should be noted that the covering should not directly touch the concrete surface until the concrete is finally set.
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The maintenance period is more than seven days according to the specification, but in the actual construction process, for various reasons, we generally water for three or four days, and tell you a way, as long as you see the color of the floor slab whitish, that is to water. 1. The concrete strength of the span of more than 8 meters is 100, and the mold can be removed only after 75 meters of 8 meters and 8 meters; Concrete strength when the floor can be on the person and construction. (Generally, after watering, the intensity of 24 can reach, and 7 9 days under normal maintenance in spring, summer and autumn; In winter, under normal maintenance for 10 to 15 days, the mold can be removed).
2. Under normal maintenance, it should not be less than 2 times a day; Make sure there is 11 16 standing water on the floor each time. 3. The moisturizing and curing of concrete is very important for the growth of its strength and the improvement of various properties, especially the early proper maintenance can avoid surface dehydration and greatly reduce the occurrence of expansion cracks in the initial stage of concrete. Therefore, the necessary maintenance after the floor concrete pouring (generally advisable 24) must be guaranteed, such as in the actual construction, due to the rush to catch up with the construction period and watering will affect the elastic line and the construction personnel operation, the construction must insist on covering the sack or straw bale for about a week of proper moisturizing and curing.
4. The mold can be removed when the strength of the floor slab reaches 75 or more. 5. When living, the load-bearing furniture should be placed separately and not too concentrated, such as pianos, refrigerators, solid wood cabinets, etc. 6. During the decoration, the cast-in-place floor slab can not be slotted or punched, and the main steel knot structure cannot be damaged, otherwise there is a risk of collapse, which will seriously affect the safe use.
7. In daily life, mop the floor frequently.
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Test methods and precautions for rapid curing of cement.
After the test body is formed, it is immediately placed in a room temperature curing box for 4h and 15min together with the test mold.
Put the test body with the mold into the test body rack in the humidity curing box and close the box lid.
3.Open the lid of the box, take out the mold test, cool it in the laboratory for 50min and 10min and then demold.
4.The difference in the overall time of each test from the test body maintenance should not exceed 30min.
Notes:
1.Add an appropriate amount of water to the box, and the water level is too low to cause dehydration damage to the heating pipe.
2.The power supply must have effective grounding, otherwise it is strictly forbidden to use, and it must meet the relevant national safety standards before it can be used.
3.After putting water in the box, it should be cleaned and kept clean.
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Curing cement is to prevent cement from cracking. After the cement is solidified, in principle, it can be raised by water for another one or two hours, and the water should flow in as much as possible when adding water to prevent it from rushing into the cement floor and causing traces and cracking after drying.
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Are you talking about cement test blocks? If the cement test block needs to invade the water, take it out when measuring. Concrete just needs to keep the surface moist and that's it.
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When the cement is in a dry warehouse, I put it up with a wooden strip and do not get wet.
If the concrete is wetted with water, it can last for more than 14 days.
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The main method of cement mortar curing is natural curing, natural curing refers to the maintenance measures such as covering, watering and moistening, windshielding, and heat preservation of the mortar under natural conditions (higher than 5), and natural curing is divided into two kinds of covering watering curing and plastic film curing.
Covering watering and curing should be covered with appropriate materials such as straw curtains, sawdust, wet sand and other appropriate materials within 3 12 hours after the mortar is poured, and often watered to keep it moist, the watering and curing date shall not be less than 7 days and nights, the number of daily watering times to keep the mortar has enough moist state is appropriate, the general temperature is above 15, in the first three days and nights after the mortar is poured, at least once every 3 hours during the day, and should be watered twice at night, in the subsequent maintenance, should be watered about 3 times every day and night, In dry climates, the frequency of watering should be increased appropriately, and large areas of floor slabs can be maintained with animal water.
The plastic film curing is to use the plastic film as the covering, so that the mortar is isolated from the air, the water is no longer evaporated, and the cement is condensed and hardened by the water in the mortar to complete the hydration effect.
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