TY - GEN A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Gardei, André A1 - Kohl, Christoph A1 - Wiggenhauser, Herbert ED - Naus, D. J. T1 - Improvement and combination of echo methods for NDT of concrete elements T2 - 2nd International RILEM Workshop on Life Prediction and Aging Management of Concrete Structures (RILEM proceedings : PRO 29) T2 - 2nd International RILEM Workshop on Life Prediction and Aging Management of Concrete Structures CY - Paris, France DA - 2003-05-05 PY - 2003 SN - 2-912143-36-5 IS - 29 SP - 137 EP - 147 PB - RILEM Publications CY - Bagneux AN - OPUS4-2621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -