The city-building technology of this era is far less developed than that of the Ming and Qing dynasties, and most of the cities are earthen cities, just like the Jingzhou city (not Xiangyang, Jiangling) was originally a soil city in the Eastern Han Dynasty, and it was not until the Southern Song Dynasty that the brick city began to be built. Pen × fun × Pavilion www. ｂｉｑｕｇｅ。 ｉｎｆｏ

Later archaeological records show that Guan Yu guarded Jingzhou for ten years in history, repaired the city wall, and used gray-black clay and yellow-brown sand, rammed earth, rammed layer by layer, rammed layer by layer, rammed layer thick, rammed nest is round.

For Wei Yan, that kind of city building technology is too backward, not to mention that Tucheng can't afford the later catapults and thunderbolts, just rain and flooding, it will cost a lot of manpower and material resources to repair, and it is no wonder that Guan Yu spent a lot of time repairing the city wall in Jingzhou for ten years.

Starting from this Yiyang New Town, Wei Yan wants to set an example for this era to build a city.

However, he only has ideas, in the previous life he was just a junior technician, lacking the experience of deploying people to manage the entire large project, in this life, his family's dock fort was only built of rammed earth, not a brick city, he needed a talent who could manage this big project.

Now that he has only Deng Zhi by his side, a political talent, he asked Deng Zhi if he could shoulder this heavy responsibility.

Deng Zhi said with a smile: "My lord, my subordinates have never had experience in building cities, but Li Yan and Li Zhengfang have been responsible for the repair of Wancheng City, and he should be able to take on such an important task." ”

Wei Yan suddenly remembered that Li Yan was in Qianwei Taishou, chiseled through Tianshe Mountain, built a road along the river, built a large number of buildings, and renovated the county town, so that "the people are happy...... The view of the building is magnificent, for a state of victory". This person is good at building, has experience in building cities, and has a vigorous and resolute style, and is definitely able to take on such important responsibilities.

Wei Yan hurriedly asked Deng Zhi to go back to Li Yan, and Deng Zhi temporarily replaced the county lieutenant of Pingchun, and Li Yan was the Cheng of Yiyang County, mainly responsible for the construction of Yiyang New City.

As soon as Deng Zhi came out of Weijiawu Fort, he met Li Yan outside the door.

It turned out that Li Yan also thought of this problem, and after walking for a few miles, he went home and came to ask for help.

"It's really the same thing that heroes see!" Li Yan and Deng Zhi looked at each other and smiled, handing over the matter.

Li Yan undertook the heavy task of building the city, commanding more than 100,000 soldiers and civilians to build a new city.

Wei Yan explained some requirements to him: "First of all, use triple soil for rammed earth. ”

It is important to emphasize here that triad soil is definitely not a binder for bricklaying, but a kind of rammed earth.

During the Three Kingdoms period, there was no Sanhe soil, and it was not until the Eastern Jin Dynasty that a certain amount of sand and lime was added to the ordinary rammed earth, so as to form the Sanhe soil, which was more solid than the ordinary rammed earth, and reached the point where the knife cone was inaccessible.

The rammed earth is covered with bricks on both sides, and this is put in the back.

Some people ask why not use concrete, the reason is very simple, the cement has not come out yet, that is, it has come out, with the output at this time, at most enough to bond masonry, not enough to get out of the main body of the city wall, and the cost is also a problem.

Li Yan looked surprised: "Lord, what is Sanhe soil?" ”

Wei Yan asked people to find some lime, loess, and sand and gravel, mix them together according to the ratio of 631, and then mix in a little tung oil, which mainly plays a role in cohesiveness, which is equivalent to the cement slurry in concrete.

After mixing these materials, they are stacked in a square mold, and then they are repeatedly knocked with a mallet until the surface is smooth, which is very critical and can play the role of coagulation and solidification.

After beating for half an hour, a box of hard dry sand and gravel actually knocked out of the water and turned into a whole piece of yellow soil.

Wei Yan said to Li Yan: "This kind of triple soil, the more times it is beaten, the longer it is placed, and the stronger it is. Beat for a few days and then pile it up. ”

After many days, the soil was dry, hard and hard like stones, and the surface of the soil was beaten with a shovel, and the result was not broken, leaving only white scratches.

Later, Wei Yan also tried to get some concrete to compare with Sanhe soil.

Compared with the hardness of concrete, the concrete is harder at the beginning, and the concrete can reach the initial setting in 3 hours and can be condensed in 3 days; The triad soil is different, the early can only be tamped by artificial patting, to achieve the purpose of shaping and hardening, but after a long time, lime and loess, carbon dioxide in the air and other reactions will be petrified, if the concrete is not reinforced, the hardness and durability of the triad soil are stronger than concrete.

Wei Yan also did an experiment, picked up an iron hammer, and slammed it down with a few hammers, but the Sanhe soil did not crack, leaving only some depressions; But with the same strength, the concrete without steel has been knocked apart.

Wei Yan understands that concrete, without plasticity, is the ability to deform, and it is generally easy to break when it is knocked.

This is one of the reasons why those walls have stood for thousands of years without falling, while many modern buildings have collapsed in a few decades.

Subsequently, Wei Yan put forward a key requirement: "Wrap green bricks inside and outside the rammed earth to build a brick city." ”

Li Yan was a little puzzled: "Lord, what we are building is only a new county town, is it necessary to make a brick city, and now many county towns are still earthen cities." ”

Wei Yan said solemnly: "The brick city is stronger and more durable, and it is not much of a problem to soak in wind and rain, if you want to do it once and for all, you don't have to spend too much time repairing the city wall in the future, then make it a brick city, in addition, the brick city has more advantages in defending against trebuchets, rushing cars and other siege equipment." This is fundamental to our future and cannot be taken lightly. ”

Li Yan understood, but he proposed: "Lord, as the main body of the city wall, the rammed earth of Sanhe must be made and repaired first, and if Zhang Xiu's army comes early, at least there will be an earthen city to block it." ”

Wei Yan nodded: "Okay, after the construction of the earth city is completed, it's not too late to wrap the big green bricks on both sides!" ”

At this time, cement, which is used as a binder, came into being.

It turns out that there is a binder for the construction of the brick city, which is made by adding water to a kind of grass and heating into a slime, and then mixing it with an appropriate amount of lime and fine sand, and stirring it into a mixed slurry, but its pressure bearing capacity is lower than that of cement mortar.

Wei Yan was more inclined to invent cement.

But he had never been in contact with cement production in his last life, and when he read historical novels, he saw that the bridge section of making cement was flying past at a glance and ten lines, and he never thought that he would cross it one day, and he didn't remember the formula and production process of those cements, and he didn't know how to combine the modern cement process with the actual situation of the Three Kingdoms era, so he had to ask for advice on the seed artifact elf Kongkong.

Because for seed artifacts, everything has a seed, and cement is no exception, including the original cement production process suitable for the Three Kingdoms era, which is also a seed, which needs Wei Yan to exchange for 50,000 points.

It's too expensive, but Wei Yan really has no choice, so he can only redeem it with 50,000 points.

Subsequently, a piece of paper appeared in Wei Yan's hand, on which the raw materials, formula, and production process of the original cement were written in detail.

He was so angry that his hands trembled: "A thin piece of paper actually asked me for 50,000 points, you are too dark!" ”

Kongkong said arrogantly: "Who made you not read historical novels seriously before, ten lines at a glance, and skipped when you encounter technical descriptions, and now you deserve it!" ”

Wei Yan was speechless, and hurriedly asked someone to copy a few copies, saving that share from being lost, and then being blackmailed by the air.

He handed the paper to Li Yan and asked him to arrange for people to make cement according to it.

……

At this point, hundreds of miles away, Jia Xu had already ordered people to make the illusion of buying Xiongnu horses on a large scale, and secretly built siege facilities.

In Nanyang County, there are already signs of mountain rain coming.