RESEARCH ON SELF-STRESS OF STEEL BARS IN AUTOCLAVED AERATED CONCRETE SLAB BASED ON RELEASE METHOD

In order to study and analyze the self-stress and the effect of steel bars in autoclaved aerated concrete slabs, the self-stress was measured by the release method. The self-stress of steel bars in the cutting release plate was produced by the autoclaved aerated concrete slabs equipped with HPB300 steel bars. The self-stress values on compression and tension sides of the autoclaved aerated concrete slab at the mid-span and the plate end were obtained, and the influence of self-stress on the cracking moment and bearing capacity of the plate was analyzed. The test results show that the self-stress at the plate end of the autoclaved aerated concrete slab is about 56% of the self-stress at the mid-span; the self-stress of the tension zone at the plate end is about 84% of that at the mid-span. At the mid-span, the self-stress of tension zone is about 54% of that of the compression zone; while at the plate end, the self-stress of the tension zone is about 83% of that of the compression zone. In addition, the self-stress also improves the crack resistance of the plate, which has a great influence on the cracking moment. The cracking moment resisted by the self-stress is about 65.7% of the theoretical cracking moment. Reasonable calculation of self-stress can effectively utilize the crack resistance and bearing capacity of autoclaved aerated concrete slabs, which has important theoretical and practical significance for the promotion and development of autoclaved aerated concrete slabs.