See the fastest updates

After building the flower beds and laying the cement pavement, Huangshi asked them to cover them with the plastic film they bought, and then instructed them to lift the plastic film and sprinkle some water on the road every day to keep the road wet.

Huangshi said to them that this is the concrete maintenance in concrete construction, and this cement pavement is also a project in concrete construction, and the cover film and sprinkling are only one of the means of their maintenance.

"Chief, you just asked us to water and moisten the pavement before we make it, and we need to clean the base surface before we can continue to apply cement slurry. If this is not the case, it is easy to bond firmly, which will cause the road surface to be hollow and bubbling. ”

"Yes, that's right."

"Then why do you have to use this plastic after this pavement is done...... Film covered? ”

After Huang Shi saw Niu vigorously asking this question, several construction workers present also looked at him, obviously they also wanted to know the "scientific truth" of Lu Dao. Because this is not an after-dinner conversation like the "Emperor's Golden Toilet", but a safety issue related to the quality of the project, then I require myself to be able to explain the truth to them thoroughly and let them all understand, so as to ensure that they do not make such low-level mistakes.

So he explained to the first batch of modern construction workers in the 16th century in front of him, "The maintenance of this cement after molding, like the ratio of cement and sand before, as well as the quality of cement and sand, also directly affects the safety and quality of cement buildings. ”

"Don't look at the road surface now, it looks good, in fact, the cement is still continuing to hydrate, and the cement is growing stronger and stronger. Therefore, it is necessary to cover and sprinkle water in time to keep the cement surface moist enough to avoid dry shrinkage cracks on the cement surface due to drying. ”

After a pause, Huang Shi looked at the people around him who were listening carefully, although these were all the knowledge he copied from Jiang Hualong, but every time he listened to it, he had to go back and understand it again, such as what is cement hydration and the like, he had to check it on the Internet, the more he knew the Tao, the more he felt that he knew too little.

"When I just talked about cement hydration, that's what I mean...... Therefore, we should pay special attention to the early maintenance of cement buildings, which is the most important in summer and winter, and also pay attention to the cement maintenance located in the vent area. ”

Just as Huang Shi said, conscientiously doing a good job in the maintenance of cast-in-place concrete is one of the important links to ensure the strength of concrete and prevent cracks. According to the provisions of the Chinese building code, within 12 hours after the concrete is poured at room temperature, it must be covered with thermal insulation and cured, and ordinary cement cannot be less than 7 days.

If you ignore the watering and curing of concrete, on the one hand, it will reduce the strength of concrete, and on the other hand, it will make the concrete have no time to replenish water during the hardening process, so a large amount of water shortage will cause cracks. Therefore, doing a good job in watering and curing concrete can not only reduce the cracks caused by temperature, but also reduce the cracks caused by concrete shrinkage.

Of course, there are also concrete that do not need to be watered and cured, which is due to the serious shortage of construction water in many places, and the traditional method is becoming more and more difficult to adapt to the needs of modern construction. Therefore, scientists have developed a new type of material and process for concrete curing, that is, concrete curing agent, which is generally suitable for cement products of concrete projects such as highways, airports, chimneys, cooling towers, and high-rise buildings.

It is also known as concrete curing liquid, is a kind of coating material, sprayed concrete curing agent is a polymer material, sprayed on the surface of the concrete will be cured, will form a dense film, so that the concrete surface is isolated from the air, greatly reduce the loss of water evaporation from the concrete surface, so as to use the moisture of the concrete itself to maximize the completion of hydration, to achieve the purpose of curing.

But before this, Huangshi didn't know that there was such a thing in the road, so he didn't buy it, and when he knew the road, he felt that it was not necessary for the time being, after all, this is a cement floor, and it is not a high-rise building that is not easy to maintain, so let them use the traditional film and sprinkling methods to operate, after all, they are too dependent on the high-tech products of modern society, and it is not easy to improve the technical level of their workers.

However, the concrete curing agent is actually quite cheap, 1 kilogram is only 5 yuan, a bucket is 200 kilograms, the validity period is half a year, grass green liquid, non-toxic, tasteless, non-combustible, with spraying, brushing, rollers and other methods are OK.

As long as the curing agent is evenly spread on the surface of the concrete, the general dosage is 3 square meters per kilogram, and then according to the need, wait for the curing agent to basically form a film, and then spray it in the vertical direction of it for the second time.

"Chief, what if it rains?"

"Nothing, nothing when it rains, and ah, if our moisturizing film is not enough in the future, you can also use geofelt, geotextiles, sacks, straw bags, straw curtains and other such things, plus this wet maintenance method of sprinkling. Keep their surfaces moist at all times and determine how many times they should be sprinkled per day. ”

Listening to the chief's talk about so many requirements, a young worker muttered in his mouth, "It's so troublesome, then it's better to just pour water on it, this will not be able to do it for a day." ”

"You lazy worm, you don't listen to the chief's words well, you think about stealing and playing all day long!" Niu Dali was angry when he heard this, and gave him a big cap with his big hand, so that he staggered forward and almost fell to the ground.

Xiao Gong made a bitter face, touched his head and replied, "Chief, Master Niu, I don't have it, I'm just ......"

"You still say you don't, I ......" Niu Dali listened to the fire, and even the chief on the side forgot about it, and was about to roll up his sleeves to give him a profound lesson.

Huang Shi hurriedly grabbed Niu Dali, although it seemed that there was an opportunistic meaning in Xiao Nianqing's words, but saying it now was much better than doing it on their own without knowing why in the future, so he persuaded, "Dali, don't do it, if you have something to say." ”

After finishing speaking, Huang Shi continued, "Everyone, pay attention, the method he said just now is not good, including the method of surrounding water maintenance, you can only use sprinkler water or the kind of watering can I gave you to spray water, do you understand?" ”

"Chief, I understand."

Then Huangshi talked about the start time and covering requirements of moisturizing film curing, as well as the "truth". The film should be of the right thickness and wider than the cover of 600 mm. When the two films are butt, the lap width should not be less than 400 mm, and the complete coverage of the film should be maintained at all times during curing.

Everyone nodded while listening and remembering in their hearts, that Li Chengpeng was even more clever, and he took out his pen and wrote it down a long time ago. Everyone didn't think that there are so many ways to have a black and white film, the original white bottom is a water-absorbing moisturizing film, and the upper part is a black heat-absorbing and water-insulating plastic film, so it can achieve a good thermal insulation and moisturizing effect.

"The last thing to say is that the curing time should be determined according to the growth of the compressive strength of the concrete floor, and special attention should be paid to the first 7 days of moisturizing and thermal insulation maintenance. In general, the number of days of maintenance is best 14 to 21 days, no less than 14 days in hot weather, and no less than 21 days in low humidity weather, but this is not the case with us at present. ”

Seeing that they were a little surprised because of their words, Huang Shi smiled secretly in his heart, "This is the standard of the Upper Realm Expressway, because there are cars that are heavier than the 'Decepticons' to run on the road, and only pedestrians or cars will walk in our park, so it will take about 5 to 7 days, let's set a longer time, 7 days." ”

Originally, Jiang Hualong told him that in this case, the road can be on the road in 3 days, but Huang Shi still asks for peace of mind, he doesn't want to leave deep or shallow footprints on the road like the Hollywood Walk of Fame in Los Angeles, USA, and everything should be safe.

So after that day, everyone called it a day and went back, and there was no cordon outside the park, because Huangshi had not yet bought it at that time, but just put a few yellow fenced water barriers at the four entrances of the park, and there was still some worry behind Huangshi, whether the children would be naughty and deliberately step on something.

Because before the park was completed and renovated, this has always been a children's paradise, although it was very simple at that time, it was a few garden chairs, but there were two children's outdoor swings, which made them overjoyed, one by one to play, and those benches became a good place for adults to rest and chat after dinner.

What Huang Shi feared did not happen, because after they left, when the people walked to the small park after eating, they found that the inside had changed, and a hollow wall of small half a person high had been enclosed around the perimeter, and they saw the flower beds as walls, and then the four openings were blocked by a yellow "plastic fence" that was one person high.

Seeing this, they either walked back, or sat on the chairs that were resting outside, and then turned their heads to look inside the wall, and found that there was a large garden jar inside, and then from its four sides to the entrance, there were four strips of film covered on it, and the side was pressed with green bricks, and they did not know what was in the tunnel.

And the children didn't think of a way to get in, because this look was obviously made by the chief, and it would be bad if it was broken, and the children's swing had already been moved out by Niu Dali, so they had a lot of fun outside, and they were looking forward to the completion of the new park.