Experimental Investigation on Flexural Behavior of Reinforced Concrete Beams with Externally Applied Liquid Rubber

This paper presents a technique for enhancing the cracking resistance of reinforced concrete (RC) beams through the external application of liquid rubber. To evaluate the influence of this coating on flexural performance, four-point bending tests were conducted on seven RC beams, comprising six coated beams and one uncoated control beam. The effects of coating position (beam soffit, beam sides, or both) and number of coating layers (3 or 6) on the flexural response were investigated. The results indicate that the external application of liquid rubber improves the cracking load and ductility of the RC beams to some extent, and the degree of improvement is related to the number of coating layers. Moreover, the application of liquid rubber to the tensile zone of the RC beams can moderately restrain tensile deformation of the concrete. When the coating was applied only to the beam soffit, the concrete strain at the soffit was lower than that in the tensile zone on the beam sides, resulting in a non-linear distribution of tensile strain along the section height within the pure bending region.