Doomsday disaster: Start by building a shelter

September 25.

Technological breakthroughs sometimes come unexpectedly fast.

Unlike other technologies, research on basic materials is not enough just by a flash of inspiration, but is still full of randomness and variables.

It's like drawing cards in a game card pool without a guarantee.

No one knows how many resources they have to invest before they can get a golden card by luck.

And obviously.

This time, Su Wu was very lucky.

Just two days later, the technology icon of fast cement was completely lit up.

He really got this material that transcends the times.

"The main materials are limestone and rubber, plus a small amount of catalyst."

"The cost is acceptable."

Seeing the formula of fast cement.

Su Wu first estimated its cost and difficulty in mass production.

Catalysts can be ignored.

Its use is so rare that even if it is exchanged with gold and silver, it does not need to be concerned.

Limestone accounts for the largest proportion.

But its reserves are also quite huge.

Not to mention the direct output from the small limestone mines, the hundreds of millions of tons of finished concrete in the city ruins also contain a lot of limestone.

And it is different from ordinary cement.

When making quick cement, there is no need to waste a lot of resources and labor to separate the limestone from the finished concrete first.

Just crush the concrete into powder and add it directly to the production process.

The overall cost is not much higher than digging from the limestone mine.

The real difficulty is rubber.

There are no oil fields in Jianghe City and the surrounding areas.

In a short period of time, it is basically impossible to use petroleum as a raw material to synthesize rubber on a large scale.

As for natural rubber.

Now all the creatures on the surface are almost completely extinct.

If you want to harvest natural rubber, you can only plant rubber trees from scratch in the limited space of the underground shelter.

And even if Su Wu starts planting now, it will take six or seven years to see the first batch of output.

These two ways to obtain rubber on a large scale are not easy.

But fortunately.

In the formula of quick cement, rubber is used as a secondary main material after limestone.

But its usage is not too large.

It is basically maintained at a ratio of about 1000:1.

Almost two kilograms of rubber can be used to make one ton of quick cement.

In the early stage, Su Wu can still bear this consumption for the time being.

Just use the inventory materials, or waste tires, etc., and it can be used for a period of time.

It is hard to say when the usage increases later.

After all.

No matter how large the amount of rubber is, in the end times, unless an oil field is discovered, it is also a non-renewable resource.

"Generally speaking, quick cement is still a limited and precious resource."

"It cannot be wasted too casually."

Considering this.

Su Wu did not rush to make a plan.

Instead, after mixing some samples of quick cement in the chemical laboratory.

First, a series of more in-depth practical tests were conducted on it.

During the test.

About 5 cm thick quick cement has various properties comparable to the standard exterior wall of the shelter, one meter thick concrete.

And it is better than concrete in terms of heat insulation, waterproofing, and ductility.

This means that if quick cement is used to build a shelter, it will be more fearless of high temperature and severe cold.

It also has excellent resistance to earthquakes.

At the same time, there is no need for additional waterproofing like concrete.

Quick cement itself is the best waterproof material.

In addition.

Quick cement, which can solidify quickly within three minutes, is almost as good as Su Wu's use of survival points to strengthen ordinary cement.

Theoretically, as long as there are enough of it.

Su Wu can create a miracle in the field of construction in a very short time.

Expand the scale of the shelter to an incredible level.

However, while the performance of quick cement is better than expected, the actual application cost is slightly higher than expected.

Quick cement cannot be mixed with sand and gravel, and can only be solidified by adding a little water and irradiating with special light.

This means the wall is cast by quick cement.

Its main component is quick cement.

In general concrete walls, the proportion of ordinary cement is less than one-third.

The rest is water and sand and gravel, whose cost is almost negligible.

In this comparison, under the same effect.

The gap between ordinary cement and quick cement is obvious.

It is not as exaggerated as the 20:1 gap between the concrete wall and the wall made of quick cement we saw before.

Instead, it should be reduced to about 7:1.

"There are currently 7,000 tons of rubber in stock in the warehouse."

"When the materials are ready."

"It is not difficult to produce quick cement."

"A production line can easily produce tens of thousands of tons a day."

"Therefore, there is no need to worry about supply in the short term."

"Then, if used, these quick cements should first be used in the shelters in the farmyard."

"It just so happens that the engineering team is carrying out the first phase of expansion now."

"Just cast the outermost wall after the expansion with quick cement."

"The thickness is set at 5 cm, and all performances are comparable to ordinary concrete walls one meter thick."

"In this way, the newly added space can be as safe as the original inner layer of the shelter."

"And it can also greatly speed up the expansion of the shelter."

"In addition, quick cement can be used to build underground passages."

"Connect the farmyard with each affiliated shelter."

"It is convenient for the transportation of materials between each other."

Looking at the test results of quick cement.

After calculating again, the total amount of quick cement that can be obtained at present.

Su Wu gradually has a clear positioning of its use.

7,000 tons of rubber inventory is equivalent to 7 million tons of quick cement.

This huge number.

It has far exceeded Su Wu's current digestion capacity.

It means that in the future, before Su Wu's shelter develops to a certain scale.

It can be safely regarded as a nearly unlimited resource.

Some construction plans that were originally only in the imagination can also be boldly promoted in reality.

Among these plans.

The most important one is still the expansion of the farmyard shelter.

At present, the farmyard can open up an area of ​​about 600 square meters every day.

This speed.

is not the limit of the engineering team's underground excavation and construction.

It is the limit of the cement production speed of small limestone mines.

Once fast cement is used instead of ordinary cement, the problem of material shortage is solved.

The expansion speed of the engineering team can reach at least 1,000 square meters per day, that is, 12,000 cubic meters.