In February 2015, the Architectural Institute of Japan (AIJ) published the “Outline of Recommendations for Diagnosis and Repair Methods of Fire-Damaged Buildings,” which aims to present considerations and standard methods for diagnosing fire damage and performing repairs and reinforcements on buildings affected by fire. To reflect enhancements in investigation methods and the accumulation of post-heating history data, AIJ released a revised edition in February 2024. This paper provides an outline of the revised edition, focusing primarily on the sections related to reinforced concrete buildings.

One of the techniques to detect steel fractures in reinforced concrete and prestressed concrete bridges is the magnetic flux leakage method. Judgment using machine learning requires a large dataset of many types to determine the presence or absence of steel fractures. To increase the amount of training data from actual structures with steel fractures, a mockup was created in the laboratory to confirm the parameters that affect measurements. The experimental parameters included concrete cover thickness, horizontal spacing of steel bars, fracture spacing of steel bars, number of horizontally arranged steel bars, stirrup spacing, stirrup cover thickness, and vertical spacing of steel bars. Machine learning was applied using the 754 data points obtained from both actual structures and laboratory test specimens.

Galvanized reinforcing bars are a type of corrosion protection reinforcement used in concrete structures. In 2019, the Japan Society of Civil Engineers revised the “Guideline on Design and Application Methods of Galvanized Steel Reinforcement for Concrete Structures,” introducing a performance-based design method. This has led to the increasing application of galvanized reinforcing bars to civil engineering structures. This paper introduces a case where galvanized reinforcing bars were applied to precast PC slabs, and it reports on the considerations that went into this application. It was confirmed that the quality of galvanized reinforcing bars satisfies the design values and the impact of galvanic corrosion is small in a dry environment such as the general atmosphere. Additionally, it was confirmed that the workability of galvanized reinforcing bars is comparable to that of ordinary reinforcing bars during construction using PC slabs, with the exception of plating repair.

Transition of Acceptance/rejection Criteria of Concrete Strength is reported in JSCE Standard Specification for Concrete Structures and JIS A 5308（Ready-mixed Concrete）. Acceptability Constants of Concrete Strength in Single Sampling Inspection Plans having Desired Operation Characteristics by Variables（JIS Z 9003; Standard Deviation Known and JIS Z 9004; Standard Deviation Unknown and Single Limit Specified）are also compared in both Specifications.