Three Kingdoms, at the beginning of the game, recognize the thief as the father, hit the spectacle,

The smell of this cement is actually the feeling after the powder is blown into the lung lobes, but this feeling is poisonous!

If you inhale too much or stay in an environment with flying cement for a long time, you may get cement pneumoconiosis.

He didn't want to suffer from the roots of his illness before he was old.

"Quick, hurry up and prepare a bucket of clean water and two handkerchiefs!"

……

There was another flurry of preparations. When everyone gathered around this small pile of cement powder again, they all covered their mouths and noses with wet towels, and looked curiously at the materials that had been prepared after a busy morning. .

As for Zhang Yan, the leader, as the only person present who has seen this kind of thing and actually operated it, he naturally took on the task of teaching.

"Here, next I will show you how to use this thing, please pay attention to it."

Dividing the cement in front of him into three parts with a small shovel, Zhang Yan looked at the pile of powder and hesitated for a moment, then shoveled two more shovels out of the leftmost pile, and added them all to the last pile.

It wasn't until the end that the weight ratio of the three piles of cement was about 1:2:3, and he stopped and heaved a sigh of relief.

"Huh, that's about it."

"...The one over there! It's you, you pour water into these three piles of cement powder, and mix them while pouring water, and just knead them into that kind of sticky paste."

Handing his shovel to another person beside him, Zhang Yan patted the floating dirt on his body, and then stood up.

After that, he looked around again, and finally, with the help of Ma Jun, he dragged three boxes made of wooden boards out of the backyard of the Science and Technology Department.

"Here, you take these boxes well, and later he will mix the cement into a paste, and you put the cement into these boxes separately."

"Remember not to confuse it! This pile is a box, don't mix them all together!"

……

These boxes nailed with wooden boards were the boxes specially used to hold fertilizers when the Lujiang Science and Technology Department was experimenting with farmyard manure.

Now that the research and development of fertilizers has come to an end, and the production work has been handed over to the Department of Industry, these boxes are just vacant, and no one uses them. They just let Zhang Yan use them to hold cement, and use it to shape the cement by the way. .

As for why the amounts of the three parts of cement are different...it is naturally because besides the cement stone that is directly solidified, there is another very common usage of cement, which is to mix cement slurry and mortar in a certain proportion to make strength and density. Concrete varies.

Since this is the first cement experiment in Lujiang, and the amount of cement powder is not much, and the amount of cement powder is only a few hundred kilograms before and after burning, so Zhang Yan did not do too many experiments, so he simply divided into three groups One group is all composed of cement slurry and solidified, the second group is mixed with one-third of the mortar, and the third group is more, mixed with about two-thirds.

After the cement slurry absorbs water and crystallizes and solidifies, the small crystals grown from the calcium silicate will firmly wrap the water and sand in the cement, forming an extremely hard and firm structure, which feels almost It's no different than rocks.

As for the shortcomings of this kind of thing...it is also very obvious.

That is all ancient cement, that is, the most primitive cement. When the temperature exceeds [-] degrees, the crystallization of calcium silicate will quickly dehydrate, and the original cement will also disintegrate and segregate, and will not return to its original appearance.

In other words, cement is good, but it cannot be used to build houses for people to live in.

Otherwise, if something like a fire breaks out, the danger of a cement-framed house is even more serious than that of a wooden frame.

Not to mention the comparison with masonry houses.

Not much to say, anyway, Zhang Yan only made cement this time to meet the needs of large-scale infrastructure such as road construction and sewer construction, and he did not intend to use cement to directly build houses, so the characteristic of cement that is afraid of fire is very important to him. It doesn't matter to him.

After all, I have only heard of the sewer spraying water, but I have never heard of anyone whose sewer is so powerful that it can even cause a fire.

Watching the laborers fill up the three boxes with cement slurry of different proportions according to his instructions, Zhang Yan raised his head to observe the time, then let out a sigh of relief, and ordered those people to put the boxes on the ground. Put it in the shade of the courtyard to prevent direct sunlight, and he led Ma Jun and Wei Xian to the door.

"It's done, let's do it first."

"I remember it took four to five or 10 minutes for this thing to start to condense and solidify, which is less than half an hour. During this time, let's go to have lunch first."

"When we come back after lunch, the mud will probably be formed."

……

He took the two of them to find a restaurant under his name near the Science and Technology Department and had a meal. Since Zhang Yan recently had his own mansion and his own cook, he hadn't eaten outside for a long time. up.

These restaurants, clothing shops, post houses and other places directly related to the basic necessities of Lujiang people are like small gold-absorbing caves. Although the daily income is not too much, there are so many of them. Where can I earn as little as I can?

It is precisely because of these things that Zhang Yan can enjoy quite favorable living conditions even though his private treasury is completely separated from the public treasury, and he can afford to support his big family by the way.

Noon passed quickly, and when the sun gradually tilted slightly to the west, Zhang Yan took the two of them back to the backyard of the Science and Technology Department. He also saw that the group of people had rested and rested, and they just had time to stay in place and wait. With a group of myself.

Chapter 44 What About Pyroxene

……

"Yo, are you all here?"

"It's almost time, you guys go and take the box apart, be careful when you take it apart, don't hurt the things inside."

……

Following Zhang Yan's order, several laborers who had been prepared for a long time rushed forward and dismantled the wooden boards of those boxes.

These boxes are not purely nailed, but are stuck together with wooden wedges one by one. Everyone can easily remove all the wooden boards outside with a few axes.

Just like gradually taking off a person's clothes, when the outer wooden boards used to fix it were all removed, the contents inside the box were suddenly exposed in front of everyone.

……

"Hey, what's going on?"

……

I saw that the mushy mud in the three boxes seemed to be fixed at this moment, and there was still a sense of liquid flowing around them, but at this moment they all stood motionless on the ground, as if three sides Like a wall made of stone.

The color of the different proportions of the mud may be slightly different, but at first glance, the creations like these three walls are as solid as rocks.

A somewhat surprised voice came from Zhang Yan's side, and there was no doubt that the voice was Ma Jun who was following behind his ass.

Ma Jun can be said to be a veteran of the Science and Technology Department.

Long before the Lujiang Science and Technology Department was established, Ma Jun was brought under his command by Zhang Yan for training because he was proficient in "scientific calculation".

Even now, everything perfected by the researchers of the Lujiang Science and Technology Department was originally created by Ma Jun. It is not unreasonable to say that he is the father of the entire Lujiang science and technology development.

But it happened that such a "big boss" who was almost second only to Zhang Yan in terms of knowledge, was looking at the solidified cement stone at this moment, and couldn't help but click his tongue in amazement.

……

"What's going on here?"

……

"Yeah, what's going on?"

……

Reaching out and gently touching the concrete solidification closest to him, Ma Jun was sure that this was definitely not what would happen after the soil dried up.

The cement stone mixed with a little sand... or almost any pulverization and cracks appeared on the top of the concrete, and it stood there as if the mud that had been stirred at the beginning had solidified directly.

Furthermore, Ma Jun just saw the entire process of cement firing and use from beginning to end.

After everyone added a lot of water to the cement powder, it was impossible for that kind of mud to dry so quickly in the shade.

Reaching out to touch the solidified stones again, a pensive look appeared on Ma Jun's face.

……

"This, is this cement?"

On the other side, Wei Xian also looked at the things in front of him with some strangeness at the moment, as if he didn't know how to evaluate them.

Just like kneading dough, a pile of powder is mixed with water to form a sticky slurry, and after waiting for half an hour, it turns out to be as hard as a stone...

No, it may still be slightly worse than stone.

With a little force on his right hand, Wei Xian squeezed the cement stone, and the huge strength of his hand immediately left a fingerprint on the previously flat surface of the cement.

Do the same thing on the other two cement stones of different colors. This time, the practical Wei Xian obviously found something different.

"Hey, my lord, these three pieces of... cement are actually different in softness and hardness?"

"Not only that, how soft is the cement stone that is all made of cement without adding sand, and it seems that it can be cracked even if it is squeezed hard. How can it be used to build buildings?"

He turned around curiously and asked Zhang Yan, and Zhang Yan saw that Ma Jun on the other side also turned around and cast him a questioning look, so he smiled and explained to the two of them.

"Okay, okay, don't pinch it. A good mud wall, if you pinch it like this, it will crack!"

"It's normal for you to feel soft when you hold it, because it takes about [-] days for cement to completely condense from the state of mud to solid, and we only took less than half an hour."

"In the construction industry, half an hour is the 'initial setting' time for cement. It just sets a shape, and the strength inside has not yet fully solidified."

"Wait a little longer. If I remember correctly, the initial setting of cement takes 45 minutes. After three days, it can reach more than 70.00% of the final strength. Finally, it reaches the standard strength after about [-] days of water injection. After that, it will not change."

"It's just that during this period of time, someone has to pour water on the cement every six hours. We don't need to worry about this. Those laborers will be responsible. We just need to see the final result."

Instructing everyone in this way, Zhang Yan looked at the three completely different cement stones and made gestures with his hands. Then he seemed to confirm something, and added a sentence later:

"Oh, by the way, you said that this piece of pure cement is softer...that's right, that's right."

"Cement becomes very strong when sand is added, but if too much is added, the cement itself is not viscous enough to hold so much sand together."

"If I remember correctly, it seems that [-]% cement mixed with [-]% sand is the limit. If it doesn't work for a long time, it will easily fall apart. But if there is less sand, there is no problem, but the strength will be lower. When weighing There is a high probability that the walls will crack."

Three times, five divisions and two divisions handed over the knowledge about cement to two people. Among them, Ma Jun will be responsible for a lot of cement improvement work in the future, and Wei Xian is the first batch of this building material after it was created. Users, so their understanding of cement must reach a certain level.

However, it is obvious that after following Zhang Yan for such a long time, we have seen a lot of unpredictable things like gunpowder and artillery. For the phenomenon of cement condensation, which is more miraculous in principle, Wei Xian and others The speed of understanding is quite fast.

In his own words, it doesn't matter how this kind of thing becomes like this, I just need to know that it will become like this, and that's fine.

Time passed slowly like this. In the afternoon, Zhang Yan had nothing to do, so he presided over a batch of cement in the Science and Technology Department.

This furnace of cement was also mixed with sand and packed in a box. It stood beside the three cement stone walls before, with a row of six pieces, which looked quite bluffing.

As for this batch of cement, Zhang Yan hardly got involved in it, and just watched silently from the side, while Ma Jun presided over the operation.

After these three days had passed, the original cement had almost hardened, and Zhang Yan and the other three people regrouped in Lujiang's Science and Technology Department.

But this time, they didn't come empty-handed, but brought something with them.

Chapter 45 Hard

"Wow... so hard!"

……

This time, when Zhang Yan and the others stood in the backyard of the Lujiang Science and Technology Department again, the concrete and stone walls in front of them had changed from three to six, and they were lined up in the courtyard.

During these three days, those responsible for maintenance poured water on the cement wall every twelve hours to ensure that the crystallization of calcium silicate in the cement would not stop.