I! Pretending to Be Reborn, Director of Doomsday Hoax

"See for yourself." Joad threw the communicator to Ain.

[Dragon Kingdom Strategic Dangerous Situation Bureau Order]:

"On August 23, Longguo time, the team led by Professor Yan Yan of Shenlong Construction Engineering Group, under the leadership of Comrade Xu Qiu, prepared a high-strength concrete with super hydrophobicity, high porosity, thermal insulation and cold resistance.

"The concrete has passed the fourth round of testing, the average low temperature resistance is minus [-] degrees to [-] degrees, and the extreme low temperature is minus [-] degrees!

"Dragon Kingdom Strategic Crisis Bureau hereby sends a letter announcing and celebrating the birth of Dragon Kingdom's severe cold concrete!" The Capitol was dead silent at the moment.

Joad looked at Campbell.

Ain also looked at Campbell.

Just a few minutes ago, the world's top expert in concrete material science also declared that as long as the essence of concrete does not change, it is impossible to use it in such severe cold...

"Professor Campbell, minus thirty to minus seventy degrees, this is the cold concrete of Dragon Kingdom." Yoder repeated.

Campbell's pupils trembled violently, and his fingers were trembling.

how is this possible? !

"In order not to delay the construction period during the Little Ice Age and the cold winter, they made cold concrete?!〃

Campbell thinks Long Guo is crazy!

The main material of the Berry Country Fortress is concrete.

The construction of the dungeon in the Dragon Kingdom actually does not need to use any cold concrete. It is under the ground and has limited influence from above.

Logically speaking, even if there is really cold concrete, it is made by Berry Country.

At this time, everyone was no longer calm.

A concrete science professor stood up.

When everyone saw the old man, they couldn't help but be in awe.

This old white professor once discovered air-entrained concrete during road construction in Kansas and New York 70 years ago.

This old professor created the history of air-entraining agents.

He said: "The addition of air-entraining agent can make the concrete meet the sufficient air content requirement, thereby improving the pore structure properties of the concrete, and improving the frost resistance and durability of the concrete...

"Before this, we had discovered many factors that can affect the frost resistance of concrete.

"For example, the air content of concrete, critical air cell spacing, water-cement ratio, aggregate, critical saturation and cooling rate, etc., are all influencing factors."

Academician Stein said: "Air-entraining can significantly improve the freeze-thaw resistance of concrete, however, the freeze-thaw resistance of concrete that has been subjected to freeze-thaw cycles for a long time depends on the severity of the weather and the frequency of freeze-thaw cycles. Therefore, from the air-entraining agent Starting from the beginning, in fact, it has come to an end.

"It is difficult for us to improve the cold resistance of concrete through simple air-entraining agents, which makes me even more curious about how Longguo did it!"

Campbell remained silent.

The reason why he dared to say that the frost resistance of concrete had almost reached its peak and could not move forward was because Berry Country had not achieved results for many years.

Moreover, they have proved a point through years of research.

The nature of the concrete pore structure is the stick that affects the durability of concrete frost resistance!

That is, the frost resistance durability of concrete changes with the properties of the pore structure. When the hole spacing coefficient is less than 250 microns, the concrete frost resistance durability index can basically reach more than 60.00%, which can withstand

Three hundred rapid freeze-thaw cycle tests.

Campbell personally carried out testing and analysis experiments on the pore structure of hardened concrete mixed with air-entraining agents, and proposed an important concept of the pore spacing coefficient that meets the requirements of concrete frost resistance and durability.This concept is now printed in the textbooks of concrete science in the world, including the textbooks of Longguo, and there are also Campbell's words!

That is, when the hole spacing is less than the critical hole spacing, the concrete is frost-resistant.As long as the amount of air-entrainment is appropriate, ordinary concrete can also obtain high frost resistance and durability.

Stein said: "The average size and spacing of air bubbles in air-entrained concrete increases with the increase of water-cement ratio, and the percentage of freezable water in the cement slurry also increases accordingly, resulting in a significant decrease in the frost resistance of concrete. Therefore, the limitation on the water-cement ratio cannot be ignored...

"We have paid attention to the amount of air-entrainment, porosity, and water-cement ratio over the years, but we have found nothing!"

Campbell and others, looking at the news released by Longguo on the communicator, were shocked in their hearts.

They are the ceiling of this industry,

Therefore, it is too clear how difficult it is to break through the cold resistance of concrete!

And at this moment,

Xu Qiu was born out of the sky with the cold concrete...

Today's low-temperature concrete, the best made, is actually only about minus [-] degrees of cold resistance,

In autumn and winter in high latitudes, half of it is basically useless.

And Xu Qiu directly doubled the cold resistance several times!

Campbell propped his hands on the table so that he could stabilize his body, and said, "We are indeed the ceiling in the field of human concrete science, but I didn't expect that Xu Qiu is the sky..."

But at this moment, it wasn't just the people in the Capitol of Berry Country who were shocked.

An earthquake is taking place in the field of concrete science in the world.

"Longguo has developed cold concrete!"

"In the past, our concrete was added with antifreeze, and it worked at a temperature of about [-] degrees below zero! Can Longguo's severe cold concrete be used normally at an environment of [-] to [-] degrees below zero?"

"How is this possible!"

"Berry Country has invested more than 300 billion yuan in research funds for concrete antifreeze projects, but failed to achieve good results. How did Long Country do it?"

"This country is creating miracles!"

"Nuclear energy difference machine, cold concrete, all kinds of shocking creations were born from the land of Dragon Kingdom... And the most frightening thing is that the same person is behind these limit-breaking things...Xu Qiu!!"

"Xu Qiu is really the savior?"

"Xu Shen faction, does it have origins?"

The world's top scientists and research institutes related to cement and concrete were all shocked beyond words by the news of Longguo!

Sakura Country.

Super Cold Resistant Concrete Research Institute, Sakura Country Concrete Science Experiment Center.

In this huge experimental center, on the screen at the entrance, the research progress of Sakura Country's technology to improve the frost resistance and durability of concrete is played.

In fact, before the Little Ice Age and the Extreme Cold Era, Sakura Country has been devoting itself to the development of highly cold-resistant concrete.

the reason is simple,

Although the land area of ​​Sakura Country is small, it is narrow and long. Therefore, a considerable part is in the severe cold zone.

Especially in the northern part of Sakura Country, many hydraulic structures will suffer from freeze-thaw damage.

According to the survey data on the durability of hydraulic structures in Sakura Country, in 32 large-scale concrete dam projects and more than [-] small and medium-sized projects,

20.00% of five dams, and 20.00% of nine small and medium-sized hydraulic structures have the problem of freeze-thaw damage.

In fact, countries such as Dragon Country, Bear Country, Maple Leaf Country, and Berry Country have also suffered from freeze-thaw damage.

The hydraulic concrete buildings built in the Northeast, North China, and Northwest regions of Longguo, especially in the severe cold regions of Northeast China,

Almost [-]% of the projects suffer from partial or large areas of freeze-thaw damage to varying degrees.

Except for the Three North regions, even in North China, where the climate is warm, concrete buildings still have a small amount of movement.

therefore,

The frost resistance and durability of concrete are actually a problem solved by global savings.

To build a building, the construction cost is actually not high, the troublesome thing is the maintenance cost!

In order to ensure the long-term use and safe operation of buildings, and to allow these projects to continue to function and benefit, various departments have to spend huge maintenance costs every year.And these maintenance costs are one to three times the construction cost...

That is,

A hydraulic structure cost [-] million to construct,

Then, the maintenance funds needed every year are around [-] million to [-] million!

As the number of concrete hydraulic structures increases, the financial expenditure of the department becomes tighter...

If the problem can be solved fundamentally and the strength, cold resistance, and durability of the concrete can be improved, then the maintenance cost will be greatly reduced!

The director of the Sakura Guochao Cold-Resistant Concrete Research Institute, looking at the notice issued by the Longguo Crisis Bureau on the communicator at this moment, is a little out of breath.They have been working in this field for more than ten years.

According to the latest engineering tests and indoor research data, they finally grasped a key point:

A very important and effective measure to improve the frost resistance of concrete is to add a certain amount of air-entraining agent to the concrete mixture.People in the engineering field know that the air-entraining agent is a surface-active substance with a water-increasing effect.

It can significantly reduce the surface tension and surface energy of the concrete mixture,

Thus, a large number of stable and small closed air cells are generated inside the concrete!

These air bubbles can cut off part of the capillary passage, relieve the expansion pressure generated when the concrete freezes, prevent the concrete from being damaged, and play the role of buffering and reducing pressure.At the same time, it can also block the passage between the capillary inside the concrete and the outside world, so that the outside water is not easy to immerse, and the permeability of the concrete is reduced.

In addition, a large number of air bubbles can also play a lubricating role and improve the workability of concrete.

Therefore, the use of air-entraining agent to make the concrete have sufficient air content, improve the pore structure inside the concrete, and greatly improve the frost resistance and durability of the concrete is almost a consensus in the engineering field.

As for Sakura Country, they focused on the air-entraining agent.

They spent more than ten years researching air-entraining agents, hoping to get a concrete that miraculously improves the frost resistance of concrete.

And now, this research is coming to an end...

The director is very clear that for the research on air-entraining agents, there is no country in the world that is more in-depth than Sakura Country (ajdf), not even Berry Country!

Originally, this air-entraining agent, which was improved, formulated, and synthesized by Sakura Country for more than ten years, was about to be born, and it would completely change the ecology of concrete in low-temperature environments in the world!

however,

At the moment Longguo released the news, decades of painstaking research in their research institute... was destroyed! !

"Even if it succeeds, our air-entraining agent can theoretically only improve the cold resistance of concrete to about minus [-] degrees..." Someone shouted in despair.

Someone showed unwillingness and said: "I still want to try, can we push our air-entraining agent to a higher height, can we create a miracle?"

Someone shook his head and sighed, and said: "Scientific research is like this. One step behind, you can't even drink soup! Moreover, the cold resistance of Longguo's concrete is between minus [-] degrees and minus [-] degrees, and the extreme cold resistance can reach minus seven. Ten degrees! This is concrete that can be used and mixed in the North and South Poles!!"

Hearing this, the director no longer had great expectations for the air-entraining agent in his research institute.

but,

There is an essential difference between the severe cold concrete of Long Country and the concrete prepared with special air-entraining agent of Sakura Country.

For the former, no special air-entraining agent should be used.