| 摘要 |
FIELD: construction industry. SUBSTANCE: with the aid of nondestructive methods of determination of ultimate strength P it was managed to provide that relative decrease of R under cyclic changes of external load from zero and under thermal cycling with freezing is similar if external load is increased to value Pin agreement with emergence of continuous acoustic emission AE under first loading after freezing. In this case load Pwith which continuous acoustic emission emerges in process of cyclic loading decreases due to damage of material. Relative decrease of Pcoincides with relative decrease R. Taking this into account it will be advantageous material saturated with water to freeze, to warm up and to deform gradually with external load till continuous acoustic emission will emerge and to determine corresponding value of load P. Prior to this value material should be loaded cyclically from zero, Pshould be registered in each cycle. Frost resistance of material is evaluated by number of cycles with which (P-P)/Pappears to be equal to permissible relative decrease R. Loading freezed part of surface of material with indenter it will be possible to determine residual frost resistance capability without cutting samples from body of dam. EFFECT: testing period decreased by hundred of times. 1 cl, 1 dwg |
