After more than two years of long-term construction, a high-level reservoir with an area of up to 0.1 square kilometers has finally been built on the north bank of the Leda River, 15 kilometers east of Leire County. Pen ~ Fun ~ Pavilion www.biquge.info (Please refer to Chapter 308 of "The King of German Mercenaries" for the cause)

This high-level reservoir is 20 meters high and consumes a lot of bricks, cement and steel bar. Among them, the bottom of the reservoir is paved with bricks and coated with cement as a guarantee of no leakage. On the other hand, reinforced concrete is used. Of course, it's not pure reinforced concrete, otherwise, Marlin wouldn't have that much steel. The surrounding walls are still made of bricks first, and then reinforced concrete. Although it is not comparable to the solidity of the large reservoirs of later generations, this is also a small reservoir in itself, and the strength around it is sufficient.

The reservoir is fed by the Leda River, and the craftsmen arranged dozens of Dutch windmills to deliver water to the high reservoir day and night. And the water in the reservoir has a discharge channel on the north side. But in this channel, there is a row of hydraulic hammers that work incessantly.

Because the water level of the reservoir was too high, fearing that the Dutch windmill would not be able to reach the water method, the craftsmen built a medium-force pool, which was also a cement pool. The ability to pump water into a 20-meter-high reservoir is achieved through relay pumping.

However, such a huge siege cost Marin 200,000 gold coins and more than two years of construction. But Marin can't help it, because the northwestern part of Germany is a plain area, and you can't find a place with a high water difference. Unlike England, there are many high-drop rivers in the mountains that are suitable for pushing hydraulic machinery.

In desperation, Marin wanted to use hydraulic machinery again, and he had only built a man-made high-level reservoir at the beginning. However, I didn't expect the cost to be so high. Originally, Marin planned to build a 1 square kilometer high-level reservoir, but the estimated cost at that time was 1 million gold coins, which frightened Marin. So, it was later revised to 0.2 square kilometers. However, as I repaired, I found that the cost may be higher than expected. As a result, it was changed to 0.1 square kilometers. However, it still cost as much as 200,000 gold coins. Mainly, the price of steel is too expensive. If it weren't for Marin who built an iron-making blast furnace and a steel-making open-hearth furnace, using the high-priced steel of the same era as a steel bar, the cost is estimated to have steadily exceeded one million.

Although the water storage is insufficient, there is no need to worry about running out of water because there are dozens of Dutch waterwheels pumping water non-stop. Therefore, that row of hydraulic forging hammers is very sufficient.

When Marin inspected the reservoir and the supporting forging base, the craftsmen said confidently. In the future, plate armor forging will become pediatric, and it can be mass-produced quickly......

Marin was very happy in his heart, although the plate armor would eventually be eliminated by the musket. However, when muskets were not yet widely used in Europe, plate armor was still very popular in Europe for the time being. Because of this hydraulic forging hammer, the speed of producing plate armor in the forging base will not only be accelerated, but the cost will also be greatly reduced.

Moreover, the hydraulic hammer can be used not only to make plate armor, but also to forge weapons such as swords. Plate armor will be obsolete in a few decades, but swords will last longer than plate armor. At least, the cavalry held out until the first half of the 20th century, when machine guns became widespread. Accompanying the cavalry, naturally, is the cavalry knife.

Looking at the large row of hydraulic hammers, Marin was also eager to try it - he was ready to become an international arms supplier. Of course, instead of selling high-end weapons such as missiles and aircraft, it sells low-end weapons such as plate armor and swords. Moreover, selling such weapons is also very profitable.

Touching the tall walls around the high reservoir, Marin felt what it means to be firm and strong. So, Marin wanted to use reinforced concrete for his own city of Orich......

For more than two years, the steel bars of Marin's steel mill have basically been used to repair the reservoir, as has the cement. Now, after the construction of the high-level reservoir, the products of the steel mill and the cement production base are not known where to be sold. Therefore, Marin decided to add reinforced concrete to the outside of the city wall of Aurich, so that the city of Aurich would become a fortified city that could not be bombarded by artillery.

You know, Aurich is Marin's lifeblood, and he has his wife and children in it. If he was out fighting, and Aurich was breached, and his wife and children were killed, he simply didn't know how to deal with it. If his wife and children are dead, what is the point of him laying down a big country? It is estimated that it will fall apart in the blink of an eye like Alexander's empire......

Therefore, the fortification and safety of the city of Aurich is also very important.

However, once the cement was used to build the capital. Then, this kind of thing is going to be publicly displayed in front of the world. After all, Aurich is the capital, and there are more foreign envoys coming and going, so it is impossible to keep it secret.

Therefore, Marin decided to study the plot of some of the novels, claiming to the outside world that it was Roman volcanic ash......

However, I don't have a place in Italy. Therefore, a reason needs to be found. For example, his uh colony discovered a volcano that produced ash suitable for construction......

Pozzolana cement is actually a very good building material, Marin is studying history, when he was studying in his last life, the teacher introduced - Roman pozzolana cement, which is mixed with volcanic ash and quicklime to form mortar, and then mixed with volcanic tuff of different particle sizes to form a wood-like structure, adding seawater, triggering the process of thermochemical reaction.

Although this kind of pozzolana cement is moderately strong, it has a very powerful property - it can withstand wind and rain erosion. The ancient Roman concrete buildings of the city of Rome are still standing even in the 21st century. Unlike the teaching building of the university where Marin studied in the previous life, which was built in 96, the walls were cracked...... Fortunately, it is the eastern plain area, and there is no earthquake, if it is changed to the unstable area of the western crust, this kind of building quality, if it is shaken, it can kill a whole building of college students......

Of course, this is because some black-hearted businessmen use substandard materials. However, it is true that ordinary Portland cement is not as resistant to wind and rain as Roman volcanic cement cement.

Of course, that's plain Portland cement. The cement prepared by Marin using the fly ash left over after coal combustion has good crack resistance, good corrosion resistance, and is not worse than Roman cement.

The only problem is that a lot of fly ash is needed. It just so happens that Marlin uses a lot of coal to boil salt, so there is a lot of fly ash, which makes the raw materials for fly ash cement very sufficient. If you change to a few people, you may not be able to get that much fly ash.

Moreover, Western Europe, as well as the Ruhr area of Germany and the United Kingdom, is rich in coal. And this is the main reason why Britain and Germany were able to become industrial powers back then. The French want to become an industrial power, but they lack coal. So, they later became usury empires......

As for Spain and Italy, they didn't develop in the 19th century, and they can't be blamed for idiots, but they really don't have any coal...... You said that this steam engine burns coal, and there is no coal, so it will develop a ghost modern industry......

Even, the rise of China is inseparable from the massive coal reserves. Without the dust in the sky, how can we develop? Can everyone write poems and brag about becoming a developed country?

As for the formula of the cement, Marlin must be kept secret. Even, the method of manufacturing Roman volcanic ash cement, Marin had to keep it a secret. As for other people's questions, Marin said that this is a special kind of volcanic ash mined from overseas. This kind of thing, Rome also has it, well, you guys go to the city of Rome and have a look...... Now, on the Italian peninsula, there must be this kind of volcanic ash...... After all, Pompeii was buried by volcanic ash...... Why don't you go and discover Pompeii? Not only can there be volcanic ash, but you can also dig up valuable antiques......

As for other countries, such as Britain and France - sorry, your country doesn't have a volcano, so I can't help it. Or, the demon you're going to go ahead and rob Italy?

As for the issue of technical leaks, it is unlikely in this era. Why? Because there is very little population movement in this era. Because it was still in the era of serfs, the freedom of serfs was restricted, and they could not leave the manor at will. As a result, there are very few outsiders everywhere. As long as the base is located in the countryside rather than in a crowded city, secrecy can be guaranteed. Want to catch a spy? Find out who the stranger is, just arrest and torture him...... As long as the craftsman is well controlled, the possibility of leakage is very low...... Therefore, Marin has always used serf craftsmen to control it. If it were those ordinary citizen craftsmen, it would be difficult to control and it would be very easy to leak secrets......

With ancient Roman volcanic ash in front of the cover, coupled with Marin's strong military power, it is not easy to provoke, many people will probably choose to look up ancient Roman books to find the manufacturing method of volcanic ash cement. Of course, even if they found a way to make cement in ancient Rome, Marin was not worried. Because, others don't know reinforced concrete technology. This is the technology with the most military strategic value of cement......