Keangnam Building (picture aboved) with 70 floors, lofty in Pham Hung (in Hanoi, Vietnam) at first glance that is nothing special apart from the height of its fame. The difference lies within the individual block. It is a new material, much strange to constructions in Vietnam: unburned block.
When choosing this type o block, the investor has to evaluate and is convinced of its advantages (such as high strength, waterproof, bending and compressive strength, etc ... no different from normal bricks). Moreover, the red blocks are nice, fine and smooth surface. If not plastered, blocks will create a sense of fresh eyes, closed to nature.
According to representatives of Vietnam Construction Association, our Nation consumes 20-22 billion of bricks per year. Up to 2020, the number of bricks needed to build to be estimated doubles -the 40 billion of bricks.
To achieve this quantity of bricks requiring the volumn of land about 600 million m3, equivalent to 30,000 hectares of arable land. Literally, it losses a communal area into a brick kiln every year. Burned bricks also consume a lot of coal and wood energy. The brick kilns emits into the atmosphere large quantities of toxic gases.
In this context, the utilization of unburned blocks is an inevitable trend of the world. Vietnam also has had AAC, but the utilization rate is very low, accounting for only 4-5% of the national bricks.
The reason is routine using burned bricks for so long but mainly due to imported production lines and sophisticated technology leading to high brick prices. Unburned blocks have been luxury items so far.
Successful creation of unburned blocks in Vietnam
Hue Quang Technology & Trade JSC, formerly the Center for New Applied Science & Technology Transfer under Institute of Rural Development Research and Support, has launched unburned block production technology from soil and wastes after five years of study.
After consideration and evaluation, the research team divided into specific soil types suitable for production of AAC in the Northern of Vietnam is clay in Hung Ha - Thai Binh, in hills of Moc Chau - Son La, in Luc Ngan - Bac Giang, laterite soil in Ba Vi - Hanoi, Kaolin Prenn in Phu Tho, kaolin in Chi Linh - Hai Duong, Puzzolan soil in Thanh My-Son Tay, etc. ...
The land in general is characterized by high proportion of kaolin, from 15 to 30%, well suited to make unburned block technology. The land resources available in locality and little agricultural value. Production technology is not complicated and the available local materials for building in any region