Abstract: In this paper, using X-rays generated at different tube voltages (70 kV to 120 kV) with the same tube current (25 mA), four commonly used autoclaved aerated concrete block samples in China were irradiated and the air absorption dose rate was measured at the fixed point after the X-rays passed through each sample. The results show that: (1) the equivalent lead equivalent thickness of autoclaved aerated concrete block under the condition of 70 kV to 120 kV increases first and then decreases with the increase of tube voltage, reaching the maximum at 90 kV (2) the equivalent lead equivalent thickness of four kinds of autoclaved aerated concrete blocks is more than 1.0 mm, and autoclaved aerated concrete can be used as radiation protection material in some machine rooms (3) the equivalent lead equivalent thickness of autoclaved aerated concrete block is related to the dry density and thickness of the material, which is independent of compressive strength.

Key words: autoclaved aerated concrete block, radiation protection, equivalent lead equivalent thickness