When he saw this gray square, Huo Gang nodded, the color was slightly different, but this was indeed concrete, and it seemed that his cement was successfully made.

Huo Gang directly asked for the hammer used to strike iron from Lu Feng next to him, and then knocked it hard, Huo Gang did not knock on the corner, but knocked in the middle, with a dull sound of "bang", a white mark appeared on the surface of the concrete, and some debris splashed out, but very little debris fell.

Huo Gang's hands were a little numb from the shock, but Huo Gang nodded with satisfaction, it seemed that the quality of his cement was okay.

And with Huo Gang's movements, the eyes of the other people around him instantly widened, Wang Luo was the first to rush up, he was originally a mason, so he was more sensitive to this material, he rushed over and broke the edge of this square concrete with his hands, of course, he couldn't break it with his hands.

"This ...... This...... Checkmate...... That's what it is...... Cement? Wang Luo was a little incoherent with excitement.

"Yes, that's what cement does, to be precise, it's called concrete." Huo Gang smiled and pointed to the stone, "I believe you have all seen its effect, this is its greatest effect, after mixing with water, sand, and gravel, it can become as hard as a stone in just one day." ”

"If we wait for the steel to be smelted, when we pour it, we use steel as the backbone in the middle to form reinforced concrete, it will be stronger, and it will not change for decades, hundreds of years!" Huo Gang said seriously.

"This ...... This...... What a miracle! "Lu Mu and they are also a little incoherent, because they are all craftsmen, of course they understand how useful this thing is, the simplest, if the Han Dynasty Yumen Pass was built with this thing, it would not have collapsed at all!

And if you build a house with it, it won't collapse for decades! And you don't have to worry about a fire!

"No, it's not a miracle, I build a river next to it, it can be called a miracle, but it's a natural law that exists in this world, just like those prescriptions of Chinese medicine, these are the prescriptions of industry. Sun Er, Xu San, Tian Zhong. Huo Gang smiled and explained to them before he spoke.

"The subordinates are here."

"Your next task is to produce a large amount of cement according to the recipe I gave you, and in the process of production, you can build a separate cellar furnace to test different proportions of cement, the strength of the concrete made of this cement is ordinary, and the concrete strength of some cement can even exceed that of granite." Huo Gang said seriously.

Huo Gang now understands that he only needs to tell these craftsmen how to make these things, and the improvement work can be directly handed over to them, as long as they are given a way, Huo Gang believes that the ingenuity of these craftsmen can definitely improve this thing better.

"General, you haven't asked Wu Ping and them to repair Yumen Pass, are you just waiting for the cement to be made?" Huo Zheng also said with some amazement, although Huo Zheng is not a craftsman, but as a soldier, Huo Zheng understands that if such a thing is used to make the city wall, it is not only stronger and faster than the bricks and stones used to make the city wall, but it is also almost impossible to destroy.

Not only the city wall, but also the construction of houses, etc., the people in the Yumen Pass are sleeping in tents, which means that the weather is gradually starting to get warmer, if it is winter, they don't know how to spend this winter.

"Yes, if the Yumen Pass is repaired in the traditional way, just firing masonry is a huge problem, and mining stone is even more impossible." Huo Gang nodded, like the Jiayu Pass built hundreds of years later, they were all looking for clay mines in the local area to burn bricks and stones, and then transport them to the place where the Guancheng was located, and then build the Guancheng.

Not to mention the speed, it is not so simple to just fire masonry, and masonry bonding also requires a mixture of materials such as glutinous rice and lime.

For example, the Yumen Pass in the Han Dynasty is actually a loess rammed (hang) city, and there is no even fired bricks and stones, which is why there are almost no Yumen Pass and Yangguan in later generations, leaving only a very small part of the ruins.

But if there is cement, it is different, such as building a city wall, if you really want to mine neat stone from Qilian Mountain, the number of stonemasons needed is definitely an astronomical number, and concrete does not need stone, as long as crushed stone.

In this era, you certainly can't be as demanding as the later generations, like the gravel only needs to be about the same size, and it certainly can't be as strict as the building standards of later generations.

Even if it's just gravel, it won't be used in Qilian Mountain, and there is enough gravel in the mountains near Yangguan.

"Huo Zheng can order someone to send an order for Wu Ping and them to prepare gravel near Guancheng." Huo Gang thought about it and said directly.

"Yes!" Huo Zheng immediately bowed and saluted.

Sun Er and they are still studying this piece of concrete, Huo Gang thought about it, since the matter of improving the cement was handed over to Sun Er, then the carpentry can actually move together, in this era, the industry actually put aside the steel, and the one that can be called an industry on a large scale is textile, and in ancient times, textile China definitely occupied the top position.

Whether it is silk or silk silk can be sold all over the world at this time, the name of the Silk Road is not called in vain.

Huo Gang can't get a modern textile machine, but if you want to greatly improve the efficiency of weaving in this era, it is not impossible, such as the famous Jenny textile machine in history.

Of course, Huo Gang didn't actually know how to make Jenny looms, but he had heard the story of Jenny looms.

"Rumu." Huo Gang directly opened his mouth and called Lu Mu over.

"General." Lu Mu immediately stood up and spoke respectfully.

"Do you know how to make a spinning machine?" Huo Gang asked.

"Yes. This is the most basic eating craft of a carpenter. Lu Mu immediately smiled, although there are many places where carpentry is used in this era, it has to be said that making textile machines is basically carpentry.

"How soon can you make a single spinning machine?" Huo Gang nodded and asked.

"If I'm on my own, it's about five days, and if I bring these apprentices of mine, three days is fine." Lu Mu immediately spoke.

"By the way, does Yangguan have a spinning machine?" Huo Gang suddenly remembered that there were so many craftsmen in Anno's tribe, it stands to reason that there could be no spinning machine.

"Yes, there are three spinning machines." Lu Mu nodded immediately.

"Okay, Huo Gang, you immediately take someone back to Yangguan with Lu Mu, disassemble the textile machine into parts, and then rush back as quickly as possible. Forget it, let's go back together. Huo Gang thought about it, it's better to go back, Lu Mu still has things to be responsible for here, and if you go back to Yangguan, with Lu Mu's master over there, you will be a little more experienced.

It also saves running back and forth.

"Yes."