{'fraction_non_alphanumeric': 0.015113350125944584, 'fraction_numerical': 0.0, 'mean_word_length': 5.2109375, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Nondestructive evaluation of prestressing strands with magnetostrictive sensors

Magnetostrictive sensors (MsS) provide a noncontact means to transmit and detect elastic waves in a ferromagnetic material. This paper reports results of using MsS for the evaluation of debonding between seven-wire prestressing strands and concrete. Two MsS configurations are described. One uses a coil that encircles the strand, and the other does not. The advantage of the encircling coil is higher sensitivity; the advantage of the other is that it can be operated from the concrete surface and does not necessarily require removal of concrete. The results showed a correlation between signal attenuation and bond quality. The guided wave speed was also found to be inversely proportional to the bond quality.