Clay Brick Field Testing
 

Specific defects are illustrated in the tables. However, there are some simple tests which can be done in the field. Firstly, when you handle a brick, see if it's soft. Can you pick off the edges? Can you scratch the surface with your fingernail? If so, the brick is probably underfired - one of the most common problems. Now, break a brick in half. Was it easy? Is there a 'core' of different colour material? If the brick breaks easily or has a core like this, then it's underfired. What about the cross section? Are there lumps or stones, internal cracks or holes? If so, the soil probably wasn't mixed well enough.

You can tell a lot about bricks by soaking them in cold water for 48 hours. If you weigh bricks before and after soaking, you can calculate the percentage of water they absorb. A good brick shouldn't absorb more than 15% of its dry mass. If bricks are too absorbent they suck moisture out of mortar and weaken the bond. You may find the brick dissolves altogether. In this case, it's definitely underfired - and dangerous to use in any building. The presence of lime may also be detected by soaking bricks. If lime is present as lumps, it may expand and cause fractures, exposing powdery white deposits.
 

Zhengtai Machinery, as a Chinese brick making machine manufacturer, has sold its brick machine to the markets in Kazakhstan, Kyrghyzstan, India, Bangladesh and South Africa etc. and Zhengtai brick making equipments are deeply trusted by customers both at home and abroad.