Introduction

A concrete structure is constructed with its own purposes such as supporting socio-economic activities,protecting people from disasters,and ensuring a comfortable and safe life.The structure is required to maintain its function and performance to achieve these purposes during its design service life.However,serious damages have been sometimes found,which may provoke performance degradation,and even structural collapse may be consequences.The life of a structure is made up of all the activities including planning,basic and detailed designs,execution,maintenance and intervention,and decommissioning.When coordination of those activities is not ensured,such damages may be found.Therefore,it is very important to coordinate these activities sufficiently.The life-cycle management(LCM)is the overall strategy with the aim of ensuring that the structure meets the associated performance requirements.The strategy is embodied by an LCM scenario.The scenario is formulated at the time of planning and design and may be subsequently modified at each stage of structure's life-cycle.LCM also contributes to realize a sustainable society through structures.Sustainability is defined in terms of environmental,economic,and social aspects.During the life-cycle of structures,sustainability is generally considered with one or a few sustainability indicators.The introduction of LCM for a structure would contribute to all aspects of sustainability while maintaining the function and performance.This paper introduces the principles and framework of LCM for concrete structures.This paper has been prepared by editing the parts of the contents of author's previously published papers[1,2].