Reborn In 17th century India with Black Technology

Chapter 68: Cement Production

Vijayanagara Empire.

Bhartiya Military Academy of Sciences - Gunpowder Branch.

It had been nearly a month since Vijay had assigned them the task of developing gunpowder, and various experiments had been continuously conducted during this time by the different research groups. However, there has been no substantial success thus far.

A man with a balding head along with his group of researchers could be seen meticulously mixing various materials, with each ingredient prepared with absolute precision. This man appeared to be in his thirties, and his name was Manoj Reddy, the head of the 4th research group. Hailing from the Andhra region of the Empire, Manoj had always found strange things interesting and enjoyed mixing different objects to observe their reactions. This fascination had made him somewhat of an outcast among his peers, but due to his exceptional intellect and extraordinary skills in concocting medicinal mixtures, he had earned a place at the Bhartiya Academy of Civil Sciences as a group leader. More recently, in response to the foreign threat, he had been promoted to the Bhartiya Academy of Military Sciences.

" ???? Mh mh mh , hmm hmm hmm????"

As he worked, Manoj hummed along to his favourite song, a common practice for him. He had conducted this particular experiment many times, but it had always ended in failure. Instead of growing disheartened, he diligently documented each unsuccessful attempt and pondered the reasons behind the failures.

"Test 32, 15 parts saltpeter, 3 parts charcoal, 2 parts sulfur... experiment begins," he wrote in his diary. He arrived at this ratio after numerous experiments, noticing that adding more saltpeter increased the explosiveness, but too much saltpeter rendered it non-explosive. He had to find the right balance. Carefully, he packed the black powder mixture he had prepared, layering it with multiple sheets of paper for containment, and added a fuse. This idea had come to him after learning about the properties of gunpowder. Manoj took the package of gunpowder and placed it next to a standard iron armour of the Vijayanagara Empire.

Black scratches and marks covered the armour, evidence of the numerous tests it had endured.

With a sense of anticipation, Manoj had his assistant light the fuse. The assistant nervously lit the fuse and swiftly retreated to a safe distance. He had been chosen for the job because of his speed, but no matter how many times he did this, it was still nerve-wracking.

Tension built up, and everyone in the project group became quiet as the fuse slowly burned and was no longer visible. Just as Manoj was disappointed with the result...

**BOOM!**

A deafening explosion echoed, prompting all the researchers involved in the project to rush out of their rooms and witness the blast. None of them were frightened by the explosion, as they had all conducted similar experiments that had ended in failure. Nevertheless, their curiosity drew them to see who had achieved the breakthrough. Upon seeing the bald man, they quickly realized that this was the result of Manoj's experiment.

"Hehehe, we did it! Haha, God has blessed us! We did it!" Manoj and his fellow researchers exclaimed in joy, dancing around in awkward steps. Manoj saw a gaping hole the size of a fist in the iron armour. It was remarkable to note that such a significant explosion had been achieved with just a small 5-gram package of gunpowder. This marked the largest explosion recorded with any mixing ratio thus far.

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In the palace, Vijay was conducting his own experiments. He aimed to create one of the cornerstones of modern civilization: cement. While cement was not exclusive to modern civilization and had been used by the Greeks, Chinese, and even the Bhartiya civilization since ancient times, those types of cement were challenging to produce and primarily reserved for cultural relics or important buildings. For example, Roman cement utilized ash from volcanoes and water from the sea to create the famous Roman cement, which could last thousands of years until the modern 21st century.

However, Vijay wanted cement that could be mass-produced and economically viable for Vijayanagara. He had instructed artisans to build a shaft kiln for his testing purposes. This kiln, which he had constructed, was relatively small, measuring only about 5 meters and made from rocks and clay. The kiln in Bharat has a long history, it has been used for pottery, metal smelting, and brick firing since ancient times. Since he didn't have to invent anything new for the kiln construction, it progressed smoothly.

To produce cement, various materials were required, including limestone, clay, shale, iron ore, ash, slag, and gypsum. Some of these materials were optional and could be used when limestone was in limited supply. Fortunately, the Vijayanagara Empire had an abundance of limestone. To procure the necessary materials, Vijay sent the Sondagars to Shimoga in search of limestone. As for the remaining materials, clay was readily available everywhere, and the slag from iron production had already been prepared.

With all the raw materials gathered, Vijay had them crushed into fine powder. He then mixed the limestone, clay, and slag in a ratio of 4:1:1. For the next step, Vijay had the raw mixture placed in the kiln. The kiln was quickly ignited, using coal as fuel, and the temperature rapidly rose to over 1400 degrees Celsius. Due to various chemical reactions within the raw mixture, calcination took place.

"Vijay, come and have lunch," Kavya called.

One hour later, after having lunch and spending some time with Kavya, he returned to find that the raw materials in the kiln had been properly calcified. When he saw the resulting product, marble-sized clumps of cement had formed. These cement clumps, called clinker, were left to cool naturally.

"Vinod...." Vijay called.

After the cement had cooled down, he ordered Vinod to bring a servant to grind the clinker. A servant quickly arrived with a hand-operated rock grinder.

After the grinding process was completed, Vijay finally saw the familiar cement from the future.

"Finally, hehe," he chuckled. "With this, the chances of winning have been increased. Ha ha!"

Vijay thought in excitement about the future.

To test the cement he had produced, he called the artisans into the workshop and had them build a small brick wall. The bricks were made of mud, and cement was used in between them. For another test, he had the artisans mix cement, rocks, and water to form a mortar, which was then poured into a rectangular mould with wrought iron bars. This was a common technique in the future for constructing solid pillars in buildings.

After a few days of drying and tending by the servants, the cement had successfully hardened.

To test it, Vijay had a strong man bring a hammer and try to demolish the wall and the pillar. To Vijay's delight, the pillar stood still without a single crack. While there were minor cracks in the wall, it was as expected because the wall was made of mud bricks. Although the cement did not let go, the bricks began to crack, but still, the wall held on. With the improvement of brick-making technology, this drawback could be eliminated in the next few months.

With the successful production of cement, large kilns of 25 meters and above were constructed in the Shimoga area of the Empire. Fortunately for Vijay, Shimoga contained one-third of all the reserves of cement-grade limestone in the whole of Bharat. With Raya Ironworks also existing in Shimoga, the raw materials of slag, limestone, and clay were readily available within a single region.

With the successful production of the first shaft kiln in the Shimoga region, the kiln could produce around 6 tons of cement in one firing cycle. With the improved efficiency and experience of workers, this number increased to an average of 8 tons per firing cycle.

With a daily usage of 12 hours, 36 tons of cement were produced. While it was currently enough for the construction of buildings, it was nowhere near enough for the construction of roads. Next, with Vijay's order, five more kilns were constructed in Shimoga to consistently provide high-quality cement for road construction and military defence purposes.