This paper presents a study on the chloride ion ingress through uncoated sides in surface coated mortar beams. Surface coating is an effective method to prevent chloride attack in concrete structures because it significantly reduces the ingress of chloride ion through coated sides. However, since surface coating is not applicable to the whole of concrete structures, chloride ion ingress would occur through sides where surface coating is not applied. It is therefore necessary to understand the effect of surface coating to chloride ion ingress through uncoated sides. A penetration test of sodium chloride solution was conducted, and in the test sodium chloride solution was penetrated to the mortar beams through their top sides which were uncoated. Chloride ion ingress in the cross-sections of the mortar beams was analysed by measuring total chloride ion concentration and by colorimetric image of characteristic X-ray intensity by electron probe micro analyser. Analysis shows that surface coating can suppress chloride ion ingress even through uncoated sides, and it is concluded that the suppression can be caused by preventing water evaporation from coated sides. |