ELECTROMAGNETIC SIGNALS OF CONCRETE SAMPLES DURING FRACTURING UNDER COMPRESSION
混凝土样品受压破裂过程中的电磁信号

The testing study is made on the electromagnetic phenomena during fracture of concrete and the testing result indicates that some electromagnetic pulse signals occurr accompanying the microfracturing of concrete samples under the axial compression. The pulse signals start at about 80% of the fracture strength of concrete. During this period, the frequency band of the electromagnetic signals is wide and their amplitude is rather large. There is a close correlation of the occurrences between the electromagnetic pulse signals and microcracks before the main fracture of the concrete samples. Hence the electromagnetic method is considered as a hopeful method for the safety monitoring of large-scale constructions.