Deformed bars

As developed in Section 10.3, the stability of extensional flow in visco-plastic solids is governed by intrinsic properties of the solid, such as its plastic resistance, its strain-hardening rate and its strain-rate-hardening rate, through the sensitivity of the plastic resistance to the strain rate. In many instances, however, the deforming bar or fiber contains imperfections that can affect or hasten localization in necks and subsequent rupture. Such perturbations of flow by imperfections and their effect on material stability in extensional flow have been of great interest. A well-defined scenario of this was conceived by Hutchinson and Obrecht (1977) and further developed by Hutchinson and Neale (1977). 

The quantity of steel reinforcement in CRCP required is 0.6% of the concrete slab cross-sectional area, comprising 16 mm diameter deformed steel bars. The transverse steel to be used must be 12 mm diameter deformed bars at 600 mm spacings. 

There are two basic methods by which steel bolts and bars may be anchored into concrete, masonry or brickwork utilising epoxy or polyester resin grouts(5). The first involves inserting a deformed bar or bolt into a preformed or drilled hole into which the resin grout has been poured (Fig. 7.3). 

An elastic body in one dimension of space, such as a spring, a solid but deformable bar, or an elastic wire, makes up a dipole belonging to the capacitive subvariety of translational mechanics. 

Deformed bars were used for the longitudinal and transverse reinforcement. Table 11.2 reports the average yield strength (fy), ultimate tensile strength (/ ), and ultimate bar elongation (e ) of the reinforcement. The mechanical properties of the longitudinal reinforcement were obtained from tensile tests on three bar samples. 

In the case of deformed bar, the stress when 0.1 mm of slip occurs between the steel and the concrete is approximately ... 

Sapountzakis EJ, Tsipiras VJ (2010b) Warping shear stresses in nonlinear no uniform torsional vibratirais of bars by BEM. Eng Struct 32 741-752 Sapountzakis EJ, Tsipiras VJ (2010c) Shear deformable bars of doubly symmetrical cross section under nonlinear nonuniform torsional vibrations— application to torsional postbuckling configuratimis and primary resonance excitations. Nonlinear Dyn 62 %7-987... 

Referring to the property of beam-column joint, the bond strength around reinforcing bar should be examined, test data indicate that the improvements are more significant for deformed bars and negligible for plain bars. 

A.K. Panda, R.A. Spencer and S. Mindess, Bond of deformed bars in steel fibre reinforced concrete under cyclic loading , IntJ. Cement Composites and Lightweight Concrete. 8,1986, 239-249. 

T. Kanazu, Y. AoyagiandT. Nakano, Mechanical behaviour of concrete tension members reinforced with deformed bars and steel fibre , Trans. Japan Concrete Institute. 4,1982, 395 402. 

Fig. 11.13. Parallel glass spring for microforce measurements scaiming electron micrograph showing in detail a deformation bar (left) of a parallel spring, and the design of another parallel spring is shown on the right...

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