Xu Ping'an has been very moisturized recently, eats and sleeps well, and has also exercised a few pieces of pimple meat the size of duck eggs. Pen, fun, and www.biquge.info

Then, Liu Jingtian died and begged for nothing, and dragged him to the Thousand Caves and Hills alive.

"What are you going to do? Let's say first, I don't dare to lead troops to fight! But you don't have to come here to do logistics, do you? Doesn't the Lizard Fortress also have a lot of craftsmen?"

"Kukuku ~ Lizard Fortress can't work, I plan to use water conservancy this time to make a small target ......"

Xu Ping'an patted his head: "Okay, I forgot, now the kobold can only use animal power and manpower, it's time to go through a wave of science and technology trees." So what's your little goal?

"No, no, bring me an earthen cement factory, the output of several thousand tons a year is enough!"

"Soil and cement...... Thousands of tons ......"

Xu Ping'an was also from a bitter background, and he knew what the word soil and cement meant, so he began to get dizzy...... It should be said that the word soil cement is a general term for many materials.

As long as it is a mortar with similar properties to cement, and can be used to lay bricks or even make the main body of building materials, it can be hung with the word 'soil cement'.

The ancient Sanhe soil of the Chinese, the quicklime plus gypsum and volcanic ash of the Romans, two materials with completely different properties, can also be called 'earth cement'.

Of course, Liu Jingtian didn't want something that was so cumbersome to use - he didn't have so many bricks and stones to build walls, how simple and crude.

"It's best to use the kind of mortar colloidal cement, and you can also use bamboo as a skeleton instead of steel bars, which can be formed by simple pouring! Finally, pour more water on maintenance, and after a week or two, it will be basically dry and usable. ”

"Where's the dirt...... Your request is not earthy at all...... What you are talking about is whether modern Portland cement is good or not!"

Xu Ping'an thought for a while and said: "Using bamboo and wood instead of steel bars is also a problem for the service life, even if it is wrapped in cement, it will rot sooner or later...... No, isn't this the favorite thing for illegal construction? Which tofu scum engineering team did you learn the remedies?"

He couldn't help but have all kinds of doubts about this thing's life experience...... Is it not just tomb robbing?

"I remember, you said you could burn bricks, right? I have also seen a kind of clay cement for bricklaying in my hometown, the formula is very simple, otherwise, let's build a brick factory first......

Liu Jingtian shook his head: "No, no, no, I know what you said - quicklime, clay, gypsum and the like, the problem is that burning bricks is too troublesome, how can I have the time to do this with insufficient manpower, PASS! The old man has his own black technology formula, but he needs to use a hydraulic mill ......."

Confused, Xu Ping'an had no choice but to start tossing the hydraulic mill.

In fact, the technical content of the things Liu Jingtian wanted was not very high -- slag, cinder, quicklime, and gypsum were ground into fine powder and then mixed in proportion. The finer the grinding, the higher the strength of the finished product, and the performance is quite like cement, and the highest strength can reach the degree of medium and low grade cement.

Xu Ping'an's bricks are matched with mortar, and the strength of the building depends on the bricks and stones;

In Liu Jingtian's recipe, the strength of the building depends on the grinding level of the raw materials and when the bamboo and wood in the concrete, which replaces the steel bar, rots.

It's hard to say who is more advanced, but the latter is simpler and rude to use, and the service life is shorter, after all, it is the royal technology of the tofu slag engineering team......

The kobolds slowed down and began to hold on to their colonies, digging through a complex network of subterranean networks.

At the same time, on the banks of the Swallow Rock River, construction began on several complex waterwheels - wooden fan blades, iron bearings, iron-clad wooden gears, and finally a grinding machine like a grinding disc.

After all, kobolds have a large number of carpenters and blacksmiths, and if they can make cannons, they can naturally make iron bearings;

It can build ships, and there is no big problem with complex blade mechanisms;

In the end, the grinders who are the most polluted and prone to silicosis, the degenerates who were captured in the first place, come in handy at this time.

On the other side, the human looked at the comeback kobold, surprised, but more confused.

With the help of the Prophet's magic, the kobold's actions were clearly visible to everyone - they set up a pontoon overnight, ran to the outskirts of Zekran in a few days, and then suddenly got stuck......

At this time, on the human side, various hypotheses have emerged.

The only head of the Siwa regiment who knows the truth is still in the muddy swamp step by step......

However, Liu Jingtian is increasingly ignoring the local humans...... All kinds of things go their own way. If it weren't for the fact that he couldn't get by on face, maybe he would have already gone to Gotland to open three bases, who would go to the trouble of provoking the devil thanklessly?

So, the kobolds, who put aside human actions, advanced little by little in an orderly manner.

If you don't pay attention to durability, cracks, water leakage or something, soil cement is really easy to use!

Within a few days, on both sides of the pontoon bridge on the Swallowing Stone River, there were already 'cement mushrooms' popping up one by one, with small shooting ports leaking out of black holes, and there were many deer and traps around.

This thing is much more reliable than a wooden barracks!

Not afraid of fire, not afraid of demolition, only a small shooting port is exposed, and large creatures can't get in.

"Look at the old man's bunker flow! A platoon has eighteen arquebuses, and a few more guns are strengthened, and it is very easy to hold a large bunker. There are three such bunkers, and they have become bastions, unless chemical weapons are used, I can't think of how the demons can attack them. ”

Now, the most troublesome thing for kobolds is to defend the back.

Although between the Blackstone Fortress and the Thousand Caves Hill, the demon had set up a portal, Liu Jingtian didn't plan to rely on this thing - what if the demon left a back door and suddenly pitted himself once?

Let's honestly build a set of safe passages from the Thousand Caves Hills to Zekland, the capital of the kingdom.

On the way to the capital, at least four strongholds are needed to ensure the safety of people and goods.

And these four strongholds, the minimum requirements for defense, must also meet the standard of "against the surprise attack of a hundred winged demons" - the attack outside the mountain lion fortress back then really taught everyone a lesson.

Even if they had the advantage, they would have to have at least two arquebuses -- four hundred dogs' heads would have been spilled out.

In this way, it would be embarrassing to touch the kobolds under Zekland - only half of them were left, and the remaining half went to guard the intersection.

Now that there are concrete bunkers, only two hundred kobolds are needed for each stronghold, and then two companies of patrols are left on the communication line, and the rest will be spread all the way to the bunkers.