Research on Crackwidth of Concrete Beam Reinforced with Highstrength Bars

Abstract:

A test of 14 flexural members reinforced with 500 MPa bars was carried out to investigate the cracking behavior of reinforced concrete beam with highstrength bars.The crack distribution along the beam height and width and the relationship between crack width and moment were explored.This experiment and other relevant experiments results show that the sub cracks between cracks limit the width of crack when the steel bars stress is high.Crack width calculated according to GB 50010—2002 was larger than the experimental value,which means that the crack width formula could not apply to the member with highstrength bars.A comparative study of the major factor of crackwidth of this experiment and other relevant experiments data,a new crack width formula was put forward.The results of the proposed formulas were in good agreement with the experiment results.

Key words:reinforced concrete; highstrength bars; crack width; sub crack; crack spacing