Analysis of the mechanics of carbamide induced destruction of concrete and ceramic bricks

The article analyses the influence of the carbamide crystals formed in pores and capillaries on the durability of ceramic bricks and concrete. When concrete and ceramics dry carbamide crystals formed inside pores restrict shrinkage deformations and cause internal stresses. Degradation of concrete and ceramics structure takes place due to pressure that builds up when carbamide crystals grow in size as well due the difference in the coefficients of thermal expansion of carbamide crystals and ceramics or concrete. asticity modulus of carbamide was determined experimentally. An evaluation of shrinkage deformations of concrete and ceramics made it possible to calculate the pressure and allowable stresses of carbamide crystals upon the exceeding of which destruction of concrete and ceramics starts.