PURPOSES : This paper presents the experimental results of tests conducted on concrete produced with air-cooled (AS) and water-cooled (WS) ground blast-furnace slag exposed to multi-deterioration environments of carbonation and scaling. METHODS : Carbonated and uncarbonated concrete specimens were regularly monitored according to the ASTM C 672 standard to evaluate the durability of concrete exposed to both scaling and combined carbonation and scaling conditions. Additionally, mechanical properties, such as compressive strength, flexural strength, and surface electric resistivity, were analyzed. RESULTS : It was found that concrete specimens produced with AS and WS had a beneficial effect on the mechanical properties because of the latent hydraulic properties of the AS and WS mineral admixtures. Moreover, carbonated concrete showed good scaling resistance in comparison to uncarbonated concrete, particularly for concrete produced with AS and WS. CONCLUSIONS : The improved scaling resistance of carbonated concrete showed that AS is a suitable option for binders used in cement concrete pavements subjected to combined carbonation and scaling.

Method for Protect of the river levee was method for installing concrete revetment block and concrete mat method in Korea. But this method is non-environmental approach because the vegetation can not take at all. To solve these problem, the method has been applied using porous vegetation concretes. Porous vegetation concrete has filler technique to provide water retention and nutrient a into the porous interior in order to facilitate plant growth. But filler used increasing the cost and the construction period. Therefore in order to not use a filler, a high absorption rate and good absorption capacity needed aggregate. Current, Blast furnace slag aggregate has been used in architectural and civil engineering field as an alternative aggregate resources. Blast furnace slag aggregate is high absorption rate and lighter in weight per unit. This study evaluated the absorption capacity of the blast furnace slag aggregate. Phosphorus Sorption experiment was carried out to produce a cylindrical acrylic(diameter 11cm, height 90cm). There filling the aggregate, for supplying the test solution was using as a pump from bottom to top. And The water of having passed through the solution was analyzed. Results, blast furnace slag aggregate showed absorption capacity of 64~77% of PO43-P and T-P. Crushed aggregate show absorption capacity of 6~24% of PO43-P and T-P. Blast furnace slag aggregate showed excellent result of good absorption capacity compared to the crushed aggregate showed excellent result.

In this study, from the material properties of the aggregates into the actual applications were evaluated for utilizingthe air-cooled blast furnace slag as the coarse aggregates (SG) in PHC piles. The physical and chemical characters ofthe SG were satisfied the standards presented in KS F 2544 for concrete blast furnace slag aggregates. And it was satisfiedthe environmental-factor-evaluation, including the soluble, heavy metal elution and total mercury content, and etc. In casethe non-washed type SG is used, the S/A ratio adjustment according to micro-powder of the aggregate surface and chemicaladmixture adjustment are needed in order to satisfy the aimed material properties. As the replacement ratio of SGincreased, the manifestation rate of compressive strength of the PHC piles was decreased. Particularly, in case non-washingtype SG, the manifestation rate more decreased. Therefore, the elimination of the pop-out materials and cleaning processare necessary for the production process for using the SG as coarse aggregates of PHC Piles