Back In Time For Imperial Examination Chapter 274

At the end of the 11th year of the Hongzhi reign, the first type of earth-made brick cement was finally formulated. The final formula was devised by the cook brought from the Xie family's hometown.

Ryan Cui only remembered that there was an ingredient in the cement formula that could solidify after adding water. When he gave it to the servants of the Xie family to make it, they tried glue, paint, resin, clay and other materials. In the end, it was the southern chef who remembered the gypsum they used to make tofu pudding, which was a kind of material that could slowly harden after adding water.

Northern chefs who make braised tofu would never think of this.

They added cement to brick dust and lime one by one, and finally found a ratio: about 70% brick dust, 25% lime, and 50% gypsum. If gypsum is not added, the cement will quickly solidify into a lump of stone as soon as water is added, and nothing can be done. The more gypsum is added, the slower it solidifies. When half of it is added, the solidification speed is moderate, and it will start to solidify in about two or three hours. After a little watering and curing, it will be hard and not afraid of being smashed in two or three days.

Xie Ying had made a mess of the nice courtyard, and covered the walls and the ground with a layer of gray cement, which he hit several times with iron rods and stone locks after it dried. This cement dried many times faster than plaster and cement, and was extremely hard when it solidified, and could withstand his hard hits.