Experimental Research on Short-Term Maximum Crack Width of Large-Diameter Reinforced Concrete Beams

In order to study the calculation method for short-term maximum crack width of HRB400 large diameter reinforced concrete beams under normal service limit states, the short-term maximum crack width of four groups of five beams under various loads was measured, and the effects of the arrangements of large-diameter steel rebars on the inside and outside and the spacing of stirrups on the short-term maximum crack width were analyzed. Based on the measured results, suggestions for revising the short-term maximum crack width formula in the Code for Design of Concrete Structures (GB/T 50010—2010) were proposed. The results showed that when the stirrup spacing was 100 or 200 mm, the average crack spacing was close to the stirrup spacing, and the arrangements of large diameter steel rebars on the outside were more effective in reducing the short-term maximum crack width, which was about 91.5% of that arranged on the inside. The short-term maximum crack width calculated according to the specifications GB 50010—2010 was significantly larger than the experimental values, and the short-term maximum crack width calculation formula considering the effects of stirrup spacing and high stress work of the steel rebars agreed well with the measured values.