There are many shear models for reinforced concrete elements without shear reinforcement and each model shows an uncertainty in shear strength prediction. Other approaches like artificial neural network (ANN) are also used in shear strength calculation. The ratio between experimental and calculated shear strengths teta = Vexp/Vcal is often used to analyse the model uncertainty.
To avoid a failure in the evaluation of uncertainty of any shear model, I would like to know what is the minimum value of variation coefficient of teta (= Vexp/Vcal), firstly for normal concrete beams. is teta = 0.05, 0.10 oder 0.15? How to determine this value?
Best regards,
Ngoc Linh Tran