In this study, heating experiments were conducted on structural glued laminated beams for more than 60 minutes, and the variations in charring depth and residual cross-section were discussed. It was found that the variation of charring depth generally followed a normal distribution. By assuming that the corners in the residual cross-section were circular arcs, the experimental values of the remaining ratio of section modulus could be tracked with good accuracy. By calculating the charring rate as the average value added to the standard deviation, the calculated value was close to the minimum experimental value of remaining ratio of section modulus.
