Polyurea coating for foamed concrete panel: An efficient way to resist explosion

Autoclaved aerated concrete (AAC) panels have ultra-light weight, excellent thermal insulation and energy absorption, so it is an ideal building material for protective structures. To improve the blast resistance of the AAC panels, three schemes are applied to strengthen the AAC panels through spraying 4 mm thick polyurea coating from top, bottom and double-sides. In three-point bending tests, the polyurea-coated AAC panels have much higher ultimate loads than the un-coated panels, but slightly lower than those strengthened by the carbon fiber reinforced plastics (CFRPs). Close-in explosion experiments reveal the dynamic strengthening effect of the polyurea coating. Critical scaled distances of the strengthened AAC panels are acquired, which are valuable for the engineering application of the AAC panels in the extreme loading conditions. Polyurea coatings efficiently enhance the blast resistance of the bottom and double-sided polyurea-coated AAC panels. It is interesting that the polyurea-coated AAC panels have much more excellent blast resistance than the CFRP reinforced AAC panels, although the latter have better static mechanical properties.