Coal ash mixed material is manufactured by mixing coal ash as the main raw material with cement or some other solidifying material, water, etc. It is used in civil engineering, construction, agriculture, forestry, and fisheries, and has various forms and properties depending on the application. Focusing on the use of coal ash mixed material as a geomaterial, the application that allows its most abundant use, the Concrete Committee of the Japan Society of Civil Engineers discussed its design, construction and inspection methods, and in March 2021, published the compilation of its findings as Concrete Library No.159 “Guideline on Design, Manufacture and Construction Method of Coal Ash Mixed Material for Geomaterial”. This paper gives an overview and application examples of coal ash mixed materials, with particular focus on type inspection and acceptance inspection, which are the most important features of the Guideline.
The Architectural Institute of Japan published the “Japanese Architectural Maintenance Standard (JAMS-RC)” in February 2021. This standard, which consists of fi ve volumes, specifi es the series of actions for the maintenance of existing buildings, including maintenance planning, inspection, investigation and diagnosis, design for repair and rehabilitation, and execution of repair and rehabilitation. This standard applies to reinforced concrete buildings. In addition to structural concrete, it covers exterior fi nishing and waterproofi ng related matters. This paper gives an overview of each volume, with particular focus on structural concrete and contents that are common to various fi elds.
In the maintenance of concrete structures, the importance of preventive maintenance from the viewpoint of service life extension and LCC is recognized, but the implementation of preventive maintenance is not widespread. The reasons for this are that investigation, diagnosis, and repair techniques for the early stages of deterioration have not been systematized, and specific procedures for preventive maintenance have not been presented. This paper describes the results of a survey on the awareness of preventive maintenance among engineers engaged in maintenance work, preventive maintenance implementation cases, and the challenges in the way of broader implementation, as well as the current state and issues concerning survey, diagnosis and repair technologies applicable to preventive maintenance. Based on the results of the above mentioned survey, a maintenance procedure is proposed along with an example of life cycle cost estimation.