Experimental and numerical investigation of polymer-reinforced and normal autoclaved aerated concrete masonry walls under large TNT explosive loads

With features such as a low mass ratio and good heat insulation and energy absorption properties, autoclaved aerated concrete (AAC) is extensively used as a filling material for building structures. To study the failure behaviour of AAC masonry walls under explosive loads, four full-size wall specimens divided into two groups were established in a field test field: two normal masonry walls (as references), a masonry wall coated with polymer only on the back, and a masonry wall coated with polymer on both sides, where all the polymer coatings were 4 mm in thickness. The two groups of walls were each subjected to explosion tests comprising 3,000 kg and 10,000 kg of TNT. The test results demonstrated the ultimate failure patterns of the masonry walls. In addition, overpressure sensors equipped with an independently developed remote data acquisition system were used to plot the incident and reflected overpressure curves at distances of 70 m and 100 m from the two high-charge TNT explosions. The differences between the arrival times, peaks and impulses (both incident and reflected) of the tested shock waves and the CONWEP predictions were compared. Then, based on the failure patterns of the specimens, post-explosion damage assessment criteria of AAC walls were preliminarily established. The assessment results indicated that the polymer coating on the wall surface remarkably improved the blast resistance performance of the masonry walls. Finally, the cohesive zone method (CZM) was introduced to simulate the blast resistance of building structures. According to the results of a comparative analysis and simulation, the CZM model can effectively reflect the explosion responses and ultimate failure patterns of masonry walls.