Experimental investigation of the elastic modulus of high strength concrete at elevated temperatures

Concrete is susceptible to damage caused by physical-chemical processes during heating, resulting in the reduction of the elasticity modulus, which decays monotonically. After cooling, the elastic modulus is lower than for the heated concrete. After fire concrete heated above 300°C is commonly removed, but cooler concrete is often maintained in the rehabilitated structure. Therefore, the temperature-dependency of the elasticity modulus of a high strength concrete after exposure to elevated temperatures (in casu heating up to 225°C) is studied through the non-destructive techniqueof excitement impulse. In this method, the elastic modulus is measured by obtaining a natural vibration frequency from a mechanical impulse received by an acoustic sensor. The results indicate a considerable reduction of elastic modulus, in the range of 30%-35% after heating to 225°C.Concrete is susceptible to damage caused by physical-chemical processes during heating, resulting in the reduction of the elasticity modulus, which decays monotonically. After cooling, the elastic modulus is lower than for the heated concrete. After fire concrete heated above 300°C is commonly removed, but cooler concrete is often maintained in the rehabilitated structure. Therefore, the temperature-dependency of the elasticity modulus of a high strength concrete after exposure to elevated temperatures (in casu heating up to 225°C) is studied through the non-destructive techniqueof excitement impulse. In this method, the elastic modulus is measured by obtaining a natural vibration frequency from a mechanical impulse received by an acoustic sensor. The results indicate a considerable reduction of elastic modulus, in the range of 30%-35% after heating to 225°C.C