000003791 001__ 3791
000003791 005__ 20141118153346.0
000003791 04107 $$acze
000003791 046__ $$k2008-05-12
000003791 100__ $$aPečínka, L.
000003791 24500 $$aMEASUREMENT OF THE DEPTH OF SURFACE OPENING CRACKS USING IMPACT-ECHO METHOD

000003791 24630 $$n14$$pEngineering Mechanics 2008
000003791 260__ $$bInstitute of Thermomechanics AS CR, v.v.i., Brno
000003791 506__ $$arestricted
000003791 520__ $$2eng$$aCurrently, the widths of opening surface cracks in reinforced concrete structures are used together with carbonation depth or chloride effects as an evaluation index for decision making for the repair of construction together with assessment of structural safety and ageing The crack depth as a more important factor for structural lifetime management is rarely incorporated in the codes due to lack of knowledges and experiences. The time-of-flight diffraction technique developed in the early 1980s has been used widely to locate and measure defects in metal using ultrasound. In contradiction concrete is a composite material consisting of a binding material with particles like gravel, sand etc. embedded in construction medium. To overcome these difficulties, stress waves generated by mechanical impact instead of an ultrasonic transmitter are used. In this paper is presented simply method based on the propagation of the dilatation (P) and Rayleigh (R) waves excited by the impact. The theory is applied to the cracks perpendicular and oblique to the surface.

000003791 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000003791 653__ $$a

000003791 7112_ $$aEngineering Mechanics 2008$$cSvratka (CZ)$$d2008-05-12 / 2008-05-15$$gEM2008
000003791 720__ $$aPečínka, L.
000003791 8560_ $$ffischerc@itam.cas.cz
000003791 8564_ $$s435323$$uhttp://invenio.itam.cas.cz/record/3791/files/Pecinka_FT.pdf$$y
             Original version of the author's contribution as presented on CD, , page 690.
            
000003791 962__ $$r3717
000003791 980__ $$aPAPER