A new approach for determination of the shear bond strength of thin spray-on liners

•A new approach was proposed to minimize the effect of normal stress induced by shrinkage on the shear-bond strength thereby improving the accuracy in assessing the shear-bond strength of TSL materials.•This testing method meets the requirement for standard testing method and can be adopted as a standard testing approach.•The effect of humidity on the shear bond strength was analysed.•Different testing methods were compared to validate the effectiveness of the new approach.