Leslie, J. R.
Research Engineer, The Hydro-Electric Power Commission of Ontario, Toronto, Ontario
Pages: 13 Published: Jan 1951
Many of the difficulties inherent in present methods of dynamic testing can be overcome if pulse techniques are utilized. In this method the velocity of propagation of an acoustical pulse through the material is measured. The pulse velocity so obtained is unaffected by size or shape of the specimen, and the elastic modulus may be calculated using one simple formula for all cases. An electronic pulse test set developed primarily for testing concrete structures in the field is described. A pulse generator and receiver are used, applied to opposite faces of the structure. The time of travel of the pulse is measured on a cathode ray tube using a strobe circuit and direct reading dial. More than two years' experience in testing laboratory specimens, for which it is now in regular use, is described. Mass concrete in the field has been tested for both deterioration and cracking; in one case many thousand readings were taken. The instrument's application to the location of rot in wood pole specimens and to the testing of soils is also illustrated.
Paper ID: STP46814S