Construction Machine Blog

As I have mentioned in my previous articles, bricks and their construction are usually considered to be very fierce and quite resistant. However, extreme weather can still have a negative effect over time. One of these evidences is the Great Wall. Some part of the wall was built by bricks, but they have been eroded for centuries. Then what can we do to help bricks stay longer, elegant and resistant? Fortunately, waterproofing can solve at least soften this problem. As a matter of fact, both a building with brick veneer and a solid brick structure can benefit from waterproofing.

Bricks would be eroded

Bricks with waterproofing

Most sealants are made with siloxane, which chemically bonds to the material and prevents water from passing through it. This type of brick waterproofing sealant is clear, so it does not change the appearance of the building. In fact, rather than staying on the surface of the structure, brick sealant penetrates the material. It will need to be reapplied to older brick structures about every four to seven years, and newer buildings approximately every five to ten years.

Brick sealant

Brick sealant used, before and afer

A benefit of brick sealant is that, while it does not allow liquid moisture to seep through to the material, it does allow vapor to escape from the bricks. Considering that all buildings contain some moisture within the materials that needs to be let out, this is convenient. Brick waterproofing is also helpful in resisting the accumulation of dirt, so keeping a building looking as new and clean as possible can be increased by using brick sealant.

One major issue that brick sealing can help avoid is efflorescence, which is white staining often observed on brick construction. This is caused by the buildup of salts in the brick. The moisture inside each brick begins to dissolve the salt, and when the water evaporates, the salts are visible on the surface. Avoiding the white staining that occurs as a result is possible with brick waterproofing.

 Spalling is another potential problem with brick construction. It occurs when the brick begins to flake due to water freezing within it. This causes expansion and eventual flaking. Sealants made with silicone, epoxy, polyester, or acrylic materials typically do not prevent spalling, while the kind made of siloxane does.

protected by waterproofing

Protected by waterproofing

 Although brick waterproofing products usually last years, the sealant will likely have to be reapplied several times throughout the life of the building. Sticking to the suggestions of when to apply brick sealant depending on the age of the building is a good idea, but those in extreme climates will likely need to reapply more often. Just like any other waterproofed product, when water no longer beads upon contact with the brick, it is time to reseal.

If you like traveling, you must have been to China. If you went to China, you must have spectacled the Great Wall. If you visited the Great Wall, you must have touched the surface of the wall, feeling the bricks and mortars. However, when you felt them, have you ever been obsessed with them and eager to know more about them? They are trivial but indispensable; they are plain-looking but attractive; they are they are numberless but unique. Now, follow me. Let me unveil the mystery of the bricks of the Great Wall~~~

Great-Wall-of-China

bricks of the Great Wall

Where are these bricks from?

The Chinese people already got familiar with the techniques of wall-building very early. During the Warring States Period from the 5th century BC to 221 BC, some states began to build the fortifications to defend their own borders. Basing on this, the emperor of Qin built a new wall to connect all these separate remaining fortifications. At that time, the building material was mostly stones and rammed earth.

It was not until the 1400s that the bricks became the building material of the Great Wall. Since the ceramic technique was already mature that time, the bricks were hard enough to build the wall and they were easier to get than stones. As a result, bricks became the main building material for the wall. Compared to the rammed earth, bricks are stronger and more elaborate. They had dimensions of 370 (L) x 95 (H) x 187 (D) millimeters and a weight of about 10Kg.

Wall Brick(Ming Dynasty)

So back to our previous question, where dose these bricks come from? As archaeologists demonstrated, they were made in local kilns, the brick kilns, which were located mainly along the two sides of the Wall. A large number of brick kilns for the construction of Great Wall during the Ming Dynasty (1368-1644) were recently discovered near the starting point of the Wall. The following are some pictures of the “factory” of the bricks.

brick kiln of Ming Dynasty

another brick kiln of Ming Dynasty

 How many bricks building the Great Wall?

There is no official figure about the number of the bricks of the Great Wall. As a matter of fact, they are discountable. But some semiofficial data shows the exact number of the bricks, including the stones, is 651,325,878,854. Some experts consider the number even larger because the weather in China has deteriorated some of the bricks over time. The number is really surprising, but not convincing enough.

 The romance among the bricks

It is said that there is a story behind each brick of Great Wall. The number of the bricks is countless, so are the stories about it. Among so many folk story about the bricks, the most popular one may be the romantic story between Meng Jangnnv and his husband. Meng’s husband was forced to carry bricks for the wall construction. Later, he was weary out to death and was buried among the bricks. At the bad news, Meng cried sadly in front of the wall. As soon as she started to cry, the Wall began to collapse. This is the famous scene of the drama that Meng tears up the Great Wall

Romance about Lady Meng and his husband

the Statue Lady Meng