Ultrasonic Time-Frequency Response Characteristics for Damage Evolution of Back-Filling Concrete under Staged Loading Conditions

<table class="table-group" id="tab1"><tr><td><table class="table"><tr><td class="thead-hr" colspan="2"><hr/></td></tr><tr class="thead"><td class="align_left">Component type</td><td class="align_center">Dosage</td></tr><tr><td class="thead-hr" colspan="2"><hr/></td></tr><tr><td class="align_left">P. O42.5</td><td class="align_center">850 kg</td></tr><tr><td class="align_left">Sand (0 ∼ 5 mm)</td><td class="align_center">700 kg</td></tr><tr><td class="align_left">Gravel (5 ∼ 15 mm)</td><td class="align_center">850 kg</td></tr><tr><td class="align_left">Water</td><td class="align_center">325 kg</td></tr><tr><td class="align_left">Admixtures (waterproofing agent)</td><td class="align_center">1.3 kg</td></tr><tr><td class="align_left">W/C ratio</td><td class="align_center">0.38</td></tr><tr class="table-tr"><td colspan="2"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>.Composition of the concrete mix.</div>

Advances in Materials Science and Engineering

tab1

Table 1

Table 1: Ultrasonic Time-Frequency Response Characteristics for Damage Evolution of Back-Filling Concrete under Staged Loading Conditions 