The next morning, as soon as Li Min had breakfast, Bai Qing ran to Prince Liang's mansion to ask for an audience. Li Min hurriedly called him in.

After a while, I saw Bai Qing covered in dust running in from outside the hall. With two red eyes, he bowed his head and said, "Your Majesty Bai Qing, please see His Highness Prince Liang."

"Well, get up!" Li Min sipped the tea and said with a smile, "Seeing that you are here in such a hurry, it must be that yesterday's cement has been calcined, right?"

"Your Highness Yingming, the craftsmen and I worked hard all night yesterday and finally finished calcining the cement. As expected, as Your Highness said, what we got was a gray powder. I wanted to invite Your Highness to come and take a look!" Bai Qing replied very excitedly.

.

"Okay!" Li Min slapped the table, stood up, and went to the prison with Bai Qing. On the way, he specifically asked him to ride with him. As a result, Bai Qing, who was nearly fifty years old, was moved to tears along the way.

He keeps telling his gratitude and admiration, and will definitely follow Li Min's lead in the future.

It was the same lime-burning yard as yesterday, but on a mat in the middle of the yard, there was a pile of very inconspicuous gray powder. Li Min walked forward quickly, reached out and grabbed some and rubbed it: Well, it feels like

Yes, it is basically no different from the cement of later generations.

"Your Highness, is this calcined cement usable?" Bai Qing next to him asked nervously. Although the fired cement was basically the same as Li Min's description, he was still unsure, fearing that he had made some oversights that would cause the cement to become unusable.

.

"Well, you did a good job. This cement is very well calcined!" Li Min saw that Bai Qing and the craftsmen around him looked nervous, and couldn't help laughing. It seemed that they thought cement was too complicated. In fact, this thing

It's so cheap. Just ask someone to tell him how to make it, and you can make usable cement, let alone these experienced craftsmen?

Hearing Li Min's praise, Bai Qing and others were relieved. This was something Li Shimin personally told him. Although Li Min couldn't do it, the craftsmen who were mainly responsible for the work were inevitably implicated, at least not

Fined with half a month's salary.

In fact, this is not really cement, because it still needs the last step. Li Min asked someone to fetch the gypsum powder that was ground yesterday, and then added about 3% of the gypsum powder in proportion to the mix. The main reason for adding gypsum was to delay the

The hardening speed of cement facilitates subsequent construction. It was not until this time that the first batch of cement in Datang was truly successfully produced.

"Bai Qing, ask someone to prepare water, sand and gravel, and dig a five-foot-square pool on the ground. The depth should not exceed half a foot." Although the cement has been made, it is not yet time to dedicate it to his father.

, at least try it out to see what the effect is, and at least be sure of it.

When Bai Qing heard Li Min's instructions, he immediately led his people into action. Those who dug pits and those who carried water were all ready in a short time. Bai Qing and the craftsmen only received orders from above.

, they wanted to assist Li Min in baking cement, but as for what the cement was used for, they didn’t know at all. Li Min didn’t tell him when he came yesterday, and of course they didn’t dare to ask. Looking at Li Min’s posture now, he must be trying to

To test the effect of cement, these craftsmen craned their heads one by one to wait and see. After all, everyone has curiosity.

Li Min directed the craftsmen to mix sand, gravel and cement with water into a slurry, and then poured it into a square pit on the ground. In order to increase the strength of the concrete, Li Min also deliberately reduced the proportion of sand and gravel, otherwise there would be too little cement.

, Li Min even wanted to make a pure cement board directly without adding sand and gravel.

After the cement slurry was poured into the pit, Li Min asked people to use wooden boards to flatten the top, and then spread a layer of straw. He also told Bai Qing to sprinkle water from time to time so that the concrete would not crack. Bai Qing was still very serious.

Write it down with a note.

It is estimated that it will take at least a week for the concrete to be fully dry, and the craftsmen cannot wait for these seven days. So Li Min ordered Bai Qing to let the craftsmen work hard to bake the lime in the past few days, and also gave him a comparison

The task that challenges his patience is to ask him to mix cement and sand in different proportions, then make it into a concrete slab like he just did, make a comparison, and find the best ratio.

Bai Qing naturally accepted the order happily. Li Min could entrust such an important matter to him, which shows his trust in him. Moreover, this matter is not difficult. Anyone can do it as long as he puts in some effort. It was obviously given to him by Li Minbai.

Thanks to Bai Qing for figuring this out, Bai Qing was inexplicably grateful to Li Min.

After explaining the matter, there was nothing more for Li Min. However, since he had entered the imperial city, Li Min was not in a hurry to return home. He first went to Li Shimin to report the progress of the cement production. When he heard that the cement had been made,

The effect is being tested now. Li Shimin was overjoyed and patted Li Min on the shoulder and cheered. If Li Min hadn't stopped him, Li Shimin would probably have gone to admire the pool of mud-like cement slurry.

After taking care of his father, Li Min went to Wangyundian Palace to visit Concubine Yang again, but this time he fell into a trap. Concubine Yang was very dissatisfied with Li Min's "confession" to Xiao Wenxin in public at the Five Kings Banquet, and carried him away.

After being taught a lesson for a long time, I finally found a chance to escape.

Seven days passed in a flash, and two major events happened in these seven days.

The first was that the Tibetan ambassador insulted the royal family and was caught by the Jinwu Guards. He should have been sentenced to death, but he wanted to make good relations between the two countries, so he only killed a few of the Tibetan ambassador's followers. As for the ambassador Lu Dongzan himself, he was sentenced to death.

He was beaten fifty times and imprisoned for two years as punishment. Taizong Li Shimin also wrote a stern letter to Tubo Zanpu, reprimanding him in a very strong tone. At the same time, he sent General Niu Jinda to lead his elite troops.

Thirty thousand people entered Jiannan Road and closely monitored every move of the Tibetan people.

The second thing is that the brewing workshop jointly opened by Li Min, Li Daozong, Li Xiaogong and other five people has officially started brewing. Originally, the brewing workshop would not start operations until the end of the month at the earliest, but since Li Min has made the cement, so

He kept the construction in the workshop simple and made do with houses and roads for the time being. When cement came out, they would all be replaced with cement, which is much stronger than masonry and civil structures.

The courtyard where the cement was burned was officially designated by Yu Wenhu as a cement workshop. Bai Qing was fully responsible for it. Bai Qing would go to Li Min's house every morning to report all the matters in the cement workshop. Of course, the setting of the cement was even more important.

The key point of the report is that before dawn today, Bai Qing came to report that the cement had finally solidified into strong and durable concrete.

When Li Min heard the news, he immediately fell out of bed, put on his clothes as quickly as possible, went to the front hall to find Bai Qing, and the two came to the prison together.

In the courtyard of the cement workshop, in addition to the cement board that Li Min personally supervised, there are also cement boards that were later made by Bai Qing's command. Several of them are almost dry. The first cement board is already surrounded by people.

Craftsmen, everyone touched the cement board with their hands from time to time, discussing something in a low voice.

"Quickly get out of the way, Your Highness is here!" The attention of these craftsmen was attracted by the cement slabs beneath them. They didn't even notice the arrival of Li Min and Bai Qing. Bai Qing directly shouted out the reminder, which made them quickly get out of the way.

the way.

Li Min smiled and nodded to the craftsmen, and then quickly walked to the cement board. The straw on it had been swept away, revealing a very flat cement board. Li Min stepped on it with his feet and found that it had indeed condensed.

"Come here, dig out the cement board!" Li Min ordered excitedly. Immediately, the craftsmen who had been prepared came forward to dig. After a while, a half-foot-thick cement board was dug out and was dug out.

The craftsmen used sticks to support it and stood up.

"Your Highness, this cement is really a strange thing. Who would have thought that after calcining a few common materials, it can actually bond gravel and sand. It is also extremely hard. Even if it is not as good as marble, it is probably not much different.

." Bai Qing tapped the cement board with his fingers and said with admiration.

"Well, you have to try it before you know whether it is strong or not. Go get a big hammer!" Li Min will not be fooled by the appearance of this cement board. He believes that only practice is the only criterion for testing truth. If you want to

Do you know if the cement board is strong? It's very simple, just hit it with a hammer a few times and you will know.

After a while, a craftsman brought a sledgehammer with a hammer head the size of half a watermelon. Li Min took it and tried it. It felt OK, and then he swung it and hit it hard on the cement board.

"Bang~" With a muffled sound, Li Min felt his hands were numb from the shock, and his arms were also aching. Looking at the smashed cement board, only a few debris flew out, leaving a shallow dent.

That's all.

"Hiss~, it's so strong!" The craftsmen around him took a breath and exclaimed in unison.

Li Min then hit him a few more times, and finally he was so shocked that he lost all feeling in his arms, and then he stopped. Although there were traces of being hit on the cement board, it was not enough for a half-foot-thick cement board.

What kind of.

"Haha, the quality is good!" Li Min nodded with satisfaction. The quality of this cement board is almost the same as the boards made of general cement in later generations. Of course, this is mainly because the craftsmen have polished the material very finely.

From calcining to subsequent hardening, everything was done with great care. If it were to be mass-produced in the future, without the help of later generations of machinery, the quality would probably drop a bit, but it would still be enough to meet the needs of Datang at this stage.

"It's all because of your master's skillful command that we can make such a wonder as cement!" Bai Qing would not miss any opportunity to flatter Li Min. Seeing how happy Li Min was, he immediately joined in the fun and flattered him.

"Hahaha~, I'm just talking. Without the help of Bai Qing and all the craftsmen, how can we make cement? You are all waiting here. I will go and ask my father to come and take a look and help me by the way.

Please take credit, everyone!" Li Min smiled and patted Bai Qing on the shoulder and praised.

After Bai Qing and the craftsmen behind him heard Li Min's words, their happy faces almost burst into laughter. Bai Qing wanted to be humble, but Li Min had already turned around and was about to leave, but as soon as he reached the door, he suddenly turned around again

He said to Bai Qing: "Don't forget to invite brother Yuwen here. He also has a share of the credit here."

Bai Qing was shocked and immediately agreed. After watching Li Min leave, he immediately trotted to invite Yu Wenhu. At the same time, he was also rejoicing in his heart. If Li Min hadn't reminded him, he would have really forgotten to invite Yu Wenhu.

Bai Qing's immediate boss, and they were all selected by Yu Wenhu, so of course he deserves a share of the credit.
Chapter completed!