METHOD OF ENHANCING RESISTANCE TO CRACK PROPAGATION IN CONSTRUCTION Russian patent published in 1995 - IPC

FIELD: construction. SUBSTANCE: construction is heated and cooled in the direction of possible crack propagation. A member of the construction is uniformly heated up to the temperature of 5-200°K. Next the construction member is cooled into two stages. At the fist stage, controlled local cooling of the zone containing cracks is carried-out to fit the law which is defined by a relationship presented in the invention description. The cooling is carried out up to the instance when stress intensity at the top of the crack achieves the value defined by a given relation. At the second stage, the member is cooled as the whole to fit a given rate. The conditioning time at the given temperature is chosen to provide decreasing of the value of yield strength up to the value which is equal to the value of yield strength before the beginning of construction usage. EFFECT: enhanced reliability. 3 cl, 5 dwg