Shear Strength of Concrete Beams Subjected to Elevated Temperature

Abstract:

One beam subjected to room temperature and 7 beams subjected to high temperature were tested. Three sides of the beams were subjected to ISO834 standard heating curves for 2 hours, and they were tested after cooled. The effect of shear span ratio, sectional dimension and position subjected to fire were studied. The results show that after fire, shear bearing capacity of the concrete beams decreases, shearing stiffness of the member degrades, and ultimate deformation increases. The results also show that the shear bearing capacity decreases as the shear span ratio increases, the high temperature has more influence on compression zone, and depth of section of the beam with three sides subjected to fire has the same effect to shear performance as in room temperature. A finite element method is suggested to calculate the shear bearing capacity of concrete beams after fire, which has accepted accuracy.

Key words:fire, concrete structure, shear strength, residual properties