Compression failure, reinforced concrete

The test beam s destroying process of L2, L3 are similar with LI, but with the increase of reinforcement ratio, the stiffness of the test beam increased. The ductility descend. The way that the test beam destroyed gradually develop in the direction of brittle failure. The damage of L3 in compressive zone of concrete happened suddenly. It s a kind of instantaneous burst, along with the noise. The main characteristics of the load shown in Table 3. 

The deformability of FRP composites covers a good portion of the ductile range of steel. The concrete or masonry members reinforced with FRP continue to gain strength until rupture or compression failure of the concrete or masonry. Fiowever, as the FRP reinforcement ratios increase, the flexural members become progressively more and more brittle. 

EE. Richart, A. Brandtzaeg and R.L. Brown, The Failure of Plain and Spirally Reinforced Concrete in Compression, University of Illinois, Engineering Experimental Station Bulletin, Illinois, USA, 1929. 

In reinforced concrete structures, brittle failure in shear and/or bond or in the compressive zones of concrete should be prevented. 

Richart, F.E., Brandtzaeg, A., and Brown, R.L. (1929), The failure of plain and spirally reinforced concrete in compression . University of Illinois Bulletin, No. 190. Scholliers, J., and Van Brussel, H. (1994), Computer-integrated filament winding Computer-integrated design, robotic filament winding and robotic quality control . Comp. Manuf, 5(1), 15-23... 

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. 

The basic theory behind conventional reinforced concrete beam design is well known. Essentially, steel reinforcement is placed near the bottom of the beam and is used to carry the tensile stresses while the concrete at the top of the beam carries the compressive stresses. To avoid failure of this concrete in compression, the steel is actually underdesigned so that it will fail first. Thus, the concrete never reaches its ultimate capacity (5). 

Variation of strain over the compression region up to failure for the beams was found to be almost perfectly linear. Failure occurred when the ultimate compressive strain in the PC reached a value of at least 0.005. As the beams failed, the compressive concrete piece separated as a V-shape, a phenomenon already observed before with other steel-reinforced PC systems. 

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