The Expansion of Defects of Solid Fired Bricks due to their Freezing

Abstract

This article deals with defects in solid fired bricks caused by repeated freezing and defrosting. Defects can be divided into surface (visible) such as cracks or chips of the test element. The second type of defects are those in the internal structure (invisible on the surface). The defects in the internal structure can be the easiest detected by non-destructive methods such as the resonant pulse method or the ultrasonic pulse method. This article deals with the possibility of detecting defects in the internal structure of solid fired bricks and their relation to surface defects. The test elements were repeatedly frozen and defrosted, and after a certain number of cycles, changes in the internal structure were monitored by the resonance method and by the ultrasonic method. The variable for monitoring the failure of the internal structure is the relative dynamic modulus of elasticity (RDM).

Predicting the Durability of Solid Fired Bricks Using NDT Electroacoustic Methods

“…Another sub-research was to monitor the changes in first natural frequencies and transit times as a function of the number of freeze cycles. In the framework of this work, three possible types of sample defects were determined [ 18 ].…”

“…The authors of the paper have dealt with this issue in the past. In the framework of [ 18 ] 3 types of defect development have been defined: Both surface defects and defects in the internal structure of the element develop; only surface defects develop; the development of defects in the internal structure is negligible; the development of surface defects is indistinct; only defects in the internal structure develop. …”