As we all know, if we want to build any building today, we must use cement and concrete, so that the building is very strong. Cement was 1796 british though. Parker fired Roman cement with a brown appearance from marl, and by 1824 the British builder Joseph Aspo invented cement and patented Portland cement.
Before that, there was no cement in this world. However, in the absence of cement, our country still built very great buildings, and it has not fallen for hundreds or even thousands of years. For example, the Great Wall of China also has the Ming City Wall.
In 1357, the Ming Dynasty minister Zhu Sheng proposed to Zhu Yuanzhang to "build a high wall, accumulate grain, and slowly claim the king", Zhu Yuanzhang felt that it was reasonable, so he adopted it, Zhu Yuanzhang established the Ming Dynasty and ordered the construction of the city universally, the Nanjing Ming City Wall was built in 1366, after 28 years, it was completed in the twenty-sixth year (1393) of Ming Hongwu.
The Ming City Wall is currently the largest and most complete preserved ancient city wall in the world, and the Ming Dynasty City Wall can still stand today, in fact, there is a very important reason, this is because these materials were added when the Great Wall was built.
In the process of building the city wall, the most important step of the ancients was rammed earth, making mud blocks that were harder than mud, and then placing it on the outside of the city wall. As for the outside of the city wall, bluestone bricks are placed. Only with double reinforcement will the walls become stronger. In addition, it is also necessary to use a special concrete made of glutinous rice, slaked lime and limestone, which can play a certain adhesion.
Rammed earth, is to compact the soil, make very strong mud blocks, even more solid than masonry, the Ming city wall uses both bluestone bricks and rammed earth, rammed earth is used inside the city wall, the exterior is used bluestone bricks for further stabilization, and in order to prevent cutting corners, craftsmen perfunctory, etc., basically each brick and stone will be engraved with the name of the responsible worker, so that such a Ming city wall can resist cannon stone.
There is also a material in the Ming City Wall, even modern people are reluctant to use, that is, glutinous rice, although there was no cement concrete at that time, but made of glutinous rice, slaked lime and limestone mixed to make a special concrete, became very viscous, is the main adhesive material, so that the masonry of the Ming City Wall will not deteriorate and damage for a hundred years.
The scale of the Ming city wall is not small, you can also know that in order to build the city wall, a lot of glutinous rice crops were used, which caused a lot of pressure on the people, in fact, glutinous rice was not used for construction from the Ming Dynasty, dating back to 1500 years ago, construction workers mixed glutinous rice and hydrated lime and limestone into paste, called "glutinous rice mortar", mainly used for the construction of mausoleums, pagodas, walls and so on.
You know, we often use the substance of glutinous rice in our current lives. When we paste the spring joint, we will put the cooked glutinous rice on the back of the spring joint, which can be easily glued, which is the use of glutinous rice adhesion. In fact, as early as 1500 years ago, glutinous rice was used in the construction of pagodas or mausoleums.
Seeing this, I have to admire the wisdom of the ancients in architecture, what do you think?