Aztec Civilization: Destiny to Conquer America!

"Boss, I've never had a father since I was young, so I've always seen you as one!... If I become a craftsman master, I'll definitely take care of you in your old age!"

"Ha, it's not like I don't have sons! Charbird, just make sure you live up to me in the future!..."

Seeing this, Koskachi burst into laughter, feeling quite pleased in his heart. He reached out, heavily patted Charbird on the shoulder, and said with a smile.

"Work hard, you're still young! A craftsman master in his twenties, it's fortunate you followed me!... If you catch the attention of His Highness, who knows, you might even get a chance to visit Divine Power University!"

"Ah, Divine Power University? What kind of place is that?"

Hearing this, Charbird was a bit stunned, his dark face showing confusion. He never had a father since young, and his family was extremely poor, his mother even remarried. After becoming a craftsman apprentice, he belonged to the kiln master's household and had no relation with his family. As for this university, he had never heard of it.

"Ha! That place is where weeds leap and turn into corn! If you're lucky, you might even touch the edge of cocoa..."

Koskachi shook his head with a smile. He reached out, patted Charbird's head, and with a solemn expression said.

"That's a long way off. The most important thing right now is to really produce the cement that His Highness ordered!... I ask you, the mix used to repair those walls, can you recognize it if you see it again?"

"Boss, I definitely can!"

Charbird nodded heavily, responding with a smile.

"It's gray-white, choking. Fine like sand, very hard, and doesn't dissolve in water. To remember that ash, I've tasted it many times, the surface is like crushed obsidian, cutting my tongue... that taste, I'll remember it for a lifetime!"

Hearing this, Koskachi raised an eyebrow and smiled with satisfaction. He was very pleased with his apprentice's determination.

"Coming from a poor family, without such determination, how can you compete with others?..."

Thinking about this, Koskachi was a bit worried, his two sons had everything but this determination. As he looked at his apprentice Charbird, his eyes softened, and he sincerely reminded him.

"Charbird, remember! Even if it takes a long time, as long as this wall is as hard as bricks and stones in the end, you can give His Highness a satisfactory answer! And if His Highness is satisfied, you'll be prosperous!"

"Yes, Boss, I'll listen to you! I'll water this wall morning and evening!"

Charbird nodded repeatedly, while speaking, he picked up the water ladle, and poured water on the other side of the wall.

"Hmm? Your method of watering..."

Seeing this, Koskachi furrowed his brows again. His Highness explained clearly that the cement would set in a few days, adding water only in the first few days. Add ash if there's too much water, and add water if there's too much ash, stop when it hardens. But what Charbird was doing...

"Boss, don't worry! I've tried for over a month, just keep adding water! This wall seems alive, constantly absorbing water, turning hard once absorbed. There might be a water spirit inside, or how else would the soft mud turn into hard stone?"

Charbird grinned, his smile bright and confident. He had touched this wall thousands of times, indeed it seemed alive, changing every day. If there really was a spirit inside, he hoped it was a woman...

Koskachi reached out, touched both sides of the wall again. He couldn't figure it out, but the side with water added was indeed harder. After a while, he waved his hand.

"Alright! You make the decision, if it works it's your credit. If it doesn't, don't blame me for not giving you a chance!"

"Thank you, Boss!"

A loud voice echoed in the camp, resonating around the white walls, carrying a hint of joy. The master and apprentice touched the stone, closed their eyes crossing the river, but indeed took a step that could change the kingdom, even the world!

If Xiulote was here, seeing this white wall, studying it carefully for a while, he'd probably have a revelation. This is exactly the cement he wanted, not the Portland cement that appeared in later times, but the Roman cement that had been around for over a thousand years!

Portland cement, which is ordinary silicate cement, is the most common type of cement in later countryside, and it's the easiest to make. The basic manufacturing process is grinding limestone and clay into raw material, then calcining them till partially or fully melted, called clinker. Lastly, mix the clinker with iron powder or iron ore slag, grind into cement.

For making cement, all other steps can be done manually, only the calcining process requires temperatures over 1500 degrees, consuming a lot of fuel! Reaching 1500 degrees is easy in later times, but very hard in this era. Considering the consumption of charcoal and manpower costs, multiplied by huge demand, it's something the current kingdom cannot afford!

The main component of silicate cement is calcium silicate. It reacts with water to form calcium silicate hydrate (CSH) and calcium hydroxide. The real determinant of cement hardness is calcium silicate hydrate. To simply put it irresponsibly, the more calcium silicate hydrate produced, the harder the solidified cement, and the higher the strength.

Roman cement hardens by forming green calcium silicate hydrate too. Its manufacturing process requires no calcining, it's mixed in ambient temperature with quicklime+volcanic ash+water. The primary component of volcanic ash is silicon dioxide ejected from volcanic activity. In other words, silicon dioxide+calcium hydroxide+water ultimately results in calcium silicate hydrate.

This reaction process is much milder and slower, requiring constant moisture. But the final strength, i.e., the calcium silicate hydrate gel produced, is often higher than silicate cement. The further it goes, the stronger it gets, naturally fitting Central America's climate!

Of course, real Roman cement had the corrosion-resistant tobermorite (silica-alumina mineral). It could react for a long time, continuously providing strength, maintaining Roman structures' rigidity for thousands of years. The presence of this component is related to special volcanic ash.

The volcanic ash from Colima volcanic area likely lacks this component. Cement made with it, strictly speaking, can't be called "Roman cement," only "volcanic ash cement."

"Cement... truly the creation of Divine Revelation! If you mix the two ashes together, add water, and mix in sand and stone, it can slowly turn into solid blocks of stone..."

Koskachi squinted, inspecting the short wall in front. In a daze, he seemed to see a towering temple standing right before him, built by his own hands!

"...If so, building massive temples, constructing noble estates, building brick granaries, even roads beneath our feet... will no longer need expensive corn-husk slurry, nor massive blocks of stone!..."

"...If so, how much easier it will be to construct buildings! And what changes this will bring to the Kingdom of the Lake?"

Koskachi looked ahead, pondering for a long time. He had no answer, because it had never happened before, so he couldn't imagine it. He just grinned, turned and headed for his wooden cabin. He wanted to take out his treasured tequila and drink heartily with coastal salt, not stopping till drunk!

"Haha, Chief Divine bless! Divine bless His Highness... and bless us too!"