After calcination for a few hours, Zhong Shuyu ordered the kiln to be opened, and the clinker that had been formed was mixed with a certain proportion of gypsum, and the mixed material was put on the grinding disc for secondary grinding.

After grinding, the cement is finished.

Zhong Shuyu immediately asked people to mix and stir the paste on the bricks to test its coagulation.

Because this solidification takes several hours to dry.

Zhong Shuyu was made to make people paste on the first day and went to see it on the second day.

But perhaps because of the wrong proportion, the bonding effect of this first time was not very good, but fortunately, Zhong Shuyu had already prepared for this, and she continued to calcine other proportions of raw material for the second test.

In the eyes of the craftsmen below, Zhong Shuyu's behavior is simply incomprehensible.

In their opinion, it is a complete waste of materials and a waste of time.

But because Zhong Shuyu is an official, and his attitude towards them is also very good, they also expressed their incomprehension in private, and there is not much malice. wa❇p✼.f✱eng✬shuge.❇info

As for the other people in the Invention Institute, especially the other two outsiders, seeing that Zhong Shuyu has been soaking in the forging room these days to get some limestone, they are all waiting to watch the show.

Zhong Shuyu has never cared about these, and what she sees now is just the experiment at the moment.

Half a month later, under Zhong Shuyu's many rigorous proportioning experiments, she finally made a cement that satisfied her.

This time, when they saw that the two bricks fit perfectly in just a few hours, and they couldn't break it, several craftsmen who didn't understand what Zhong Shuyu did before were all amazed.

And Nie Pengju, who has been following Zhong Shuyu these days, is completely impressed by Zhong Shuyu, and no longer thinks that Zhong Shuyu is a useless scholar who can only do it.

The craftsmen are excited.

Zhong Shuyu asked them to get sand, cement and water, make concrete, and paint a layer of cement on the dirt on this side.

A day later.

Wait for the concrete floor to be basically dry.

Zhong Shuyu invited Shi Lezhang, a waiter from the Ministry of Industry, and Wang Yuankui from Langzhong of the Invention Institute.

Look at the clean, flat ground in front of you without any gaps.

Both were stunned.

Because there is no real concrete floor on the ground used in this era.

Although the Emperor of the Crossing had tried to make it, it was clear that he did not have the knowledge to do so, so he was not able to make modern cement, only some crude alternatives.

After he left, people didn't continue to study in this area.

So the ground is still slate, pebbles or dirt.

Among them, the dirt is the most used, for example, the current official roads are paved with mud soil, after all, all the roads are paved with stone slabs, which is too expensive.

Of course, this kind of dirt is not casually paved with mud, if it is just mud, then if it rains heavily in the second half of the day, it will be all slurry and slurry road, and the carriage will not be able to walk on it at all.

It is said that it is a dirt road, but it is actually paved with rammed earth, which is made of black soil or loess tamping and some coarse sand lime mortar, and it is paved with earthy yellow, so it has always been muddy soil.

Although this kind of dirt is not at all comparable to modern cement floors, it is much better than pure loess roads, even if it rains for several days in a row, at least it will not be easily deformed.

Of course, walking on it, the shoes must not be clean.

And I'll have to repair it in a few years.

Therefore, can the two of them see such a flat concrete floor without being shaken?