The appearance color of clay bricks just means that the appearance of the surface of the brick is beautiful, and the aluminum content has a certain relationship. But the relationship with physical indicators is not large.
At present, there is a wrong vision in the market, if the appearance of clay bricks is light yellow color then it's a good brick, if it's dark red, the quality is not good. What color does the appearance of clay bricks show, is related to the process ratio, if you add a high amount of aluminum flour, the appearance of the color will look good, light yellow, giving a person a comfortable feeling, from the point of view of chemical indicators, the aluminum content is indeed slightly higher.
But if the color of the brick is dark red, the appearance size can be, and the weight can also meet the standard, indicating that the internal quality of the clay brick is good. The internal quality of clay brick has a certain relationship with aluminum content and volume density.
At present, the color of clay bricks in Henan is basically light yellow, the appearance is suitable, and the weight of bricks can also be. The color of the three high aluminum bricks in Shandong and Hebei are similar, but the load softening temperature is slightly different. In fact, if analyzed from the expert point of view, the load softening temperature can best reflect the difference in the quality of clay bricks. But the load can only be tested to know, unlike the color and weight from the naked eye and pick up with the hand, it is very intuitive to know.
And another indicator, that is, the stomata, can not be intuitively seen, can only be learned by means of inspection, and can not be seen by looking alone. In addition, strength, compressive strength is also tested to know.
That is to say, the surface color of the clay brick is only related to the aluminum content, and has nothing to do with the physical indicators, so only looking at the color is not able to see the internal physical indicators of a clay brick.