This paper describes “Recommendation for Design and Construction of Electrochemical Corrosion Control Method”, Concrete Library 107, published by Japan Society of Civil Engineering in November 2001. By recommendation, the fundamental approach of the application of the Electrochemical corrosion control methods, which comprehended 4 kinds of methods of Cathodic protection method, Desalination method, Realkalisation method, Electrodeposition method were regulated, In “Design and Construction Manual of the Electrochemical Corrosion Control Method”, each methods independence design and construction technique and maintenance methods are described. In this report, the outline of Recommendation is explained, and in addition, it is introduced on present state of the Electrochemical corrosion control method.

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A seismic retrofit technique using form plates and carbon fiber sheets (CF sheets) has been developed, applicable in a short work period to columns of existing reinforced concrete buildings. This technique minimizes the generation of dust, offensive smell and noise. The present paper discusses the overview of the technique and work sequence. incombustible 13 mm thick form plates are processed into channel-shaped forms in the factory. The inner surface of the form is covered with a CF sheet that is impregnated with adhesive resin except for in its joint portion. The forms are erected on site on both sides of the column, and the joints of CF sheets alone are bonded. The 30 mm interstice between the existing column and the channel-shaped form is filled with grout to make an integrated structure. The influence of grout upon the strength of the CF sheet joint during the curing process was evaluated, in order to verify the performance of this retrofit method. In addition, the columns strengthened by the method were subjected to series of alternating loading tests with a constant axial force. Eleven test specimens were involved in the structural tests, including one without retrofit, ones directly covered with CF sheet, and the rest improved by the developed technique. The test results demonstrated that the specimens strengthened by the new technique presented a strength and a ductility of the same level as those of the specimens directly covered with CF sheet.

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It is not allowed to make openings to run pipes through in plastic hinge area of reinforced concrete beam. If it is allowed, a possibility of design will increase. This paper reports on the shear/bending test under reversed cyclic loading of reinforced concrete beam with opening at plastic hinge area. This reinforcement for opening is characterized by “II” -shaped buckling reinforcement. As a result, the flexural strength and deformability of R/C beams with opening were on a par with no opening R/C beams.

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Concrete bridges, which were built about thirty or forty years ago during Japan's high Economic growth period, currently have a couple of problems. One problem is concerning a decrease in durability caused by carbonation, salt injury, alkali-aggregate reaction, etc. The other problem is due to the depletion of the fatigue caused by the increase of traffic volume and also because the size of vehicles are becoming larger. Based on these problems, rehabilitation and reinforcement on concrete bridges are increasing as a countermeasure. This report shows the present condition examine system which supports the checking examine process. The checking examine process is one of the maintenance management processes for concrete bridges. In this present condition examine system, visual checks, which are based on a check file at the location of the bridges, are made and the date are input into a personal computer, then the condition of the bridges are evaluated and judged in the score. This system supports the maintenance management plan. Also, when using this system, ordinary construction workers are able to evaluate and judge indiscriminately to technical engineers.

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[in Japanese]

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