SPLITTING OF SOFT-MUD BRICK*

A study was made of the cause and methods of preventing the splitting of Hudson River soft-mud brick. The splitting occurred in the kiln and paralleled the 8- by 4-in face of the brick and was found to be associated with black coring. Tests made on various portions of the brick showed that the black portions were more vitreous and had lower thermal expansions than the outer, more oxidized portions. On cooling, the stresses resulting from the difference in thermal expansion were such as to tend to split the brick Modification of brick mixes and method of setting are recommended to overcome black coring.