同心式保护层结构
cable with concentric protective layer
烧蚀型保护层
ablative-type protective coating
耐火保护层
refractory protection parameters
玛帝脂保护层
mastic weatherproof coating
临界保护层厚度
critical thickness of concrete cover
开采保护层
protective layer mining first
近距离保护层
short distance protective seam