Damage-controllable structures

Abstract To ensure better performance for a range of existing reinforced concrete structures in seismic regions with substandard structural details, seismic retrofit is an economical solution. Hence, this chapter presents some of the available results in which fiber-reinforced polymer (FRP) composites can be used for damage-controllable structures. For example, the performance of existing reinforced concrete structures whose components are vulnerable to shear failure, flexural-compression failure, joint reinforcement bond failure, or longitudinal reinforcement lap splice failure and retrofitted with FRPs is described. Novel concepts of modern constructions with controllability and recoverability using FRP composites are addressed. 

Key words damage-controllable structures, existing RC structures, seismic retrofit, FRP steel-fiber composite rebars. 

Idealized load-deformation behavior of proposed damage-controlled structures. 

Table 14.1 Comparison between the performance of the normal RC structure and the damage-controllable structure...

According to the mechanical behavior shown in Fig. 14.1, Table 14.1 sununarizes the limit states and the corresponding performance levels under the action of three different levels of earthquakes for both normal RC structure and damage-controllable structure. It is clear that the proposed structure can be kept in place for a relatively long time without collapse during a large... 

Figure 14.7 shows the lateral drifts of 39 scale-model tests at the recoverability limit in comparison with the maximum achieved drifts (point D or E of Fig. 14.1 according to colunm response). Figure 14.7(a) displays colunms with flexural and lap-splice deficiencies, and columns with shear deficiencies are depicted in Fig. 14.7(b). Below the line representing the lateral drifts of the columns at the recoverability limit, columns are within the recoverable state and beyond this line, columns residual drifts are over 1%, which means columns enter into the irrecoverable state. Although lateral deformation at the recoverability limit of any of these samples does not correspond to a specific point on the idealized lateral load-deformation relationship of the FRP-RC damage-controllable structure, it is noticeable that most columns could not stay recoverable until point D of Fig. 14.1 (the end point of the achieved post-yield stiffness). 

Novel damage-controllable structures using FRP composites... 

Steel-fiber composite rebars for damage-controllable structures... 

Connor, JJ-, Wada, A., Iwata, M. Huang, Y.H. 1997. Damage-controlled structures. I Preliminary design methodology for seismically active re ons. Journal of Structural Engineering 123(4) 423 31. 

It should be noted that the oxidative stress as an important faetor of AD may be not only a souree of free radicals damaging cell structures and maeromoleeules but also a symptom of a disorder in the operation of the system of homeostasis of lipid peroxidation (LPO) in biologieal membranes. This system plays an important role in the regulation of eell metabolism it controls the strueture and structure-related funetions of various eellular membranes. 

The critical elements of fault damage zones which are needed for fault seal evaluation and for input into reservoir behaviour simulation include (i) the dimensions of the damage zone (ii) the fault clustering characteristics (iii) the fault offset populations, which can control the distribution of fault rocks and juxtapositions (iv) the orientation distributions of deformation features present within damage zones and (v) the total thickness of fault-rocks. Each of these aspects are reviewed below, where the data presented are part of a large database collected from the structural analysis of -90 wells, (-25 km of core) from the North Sea area (see example in Fig. 7). The final part of this section presents a simple model which demonstrates the impact of damage zone structures on flow. 

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