Equivalent stress block to characterise force–displacement behaviour of circular RC column considering steel bond slip

Stress block parameters are predominantly used in the design of concrete structural members and offer a convenient method to arrive at the flexural capacity. The objective is to find the equivalent stress block parameters namely, the effective average concrete ratio and the stress block depth factor for Self Compacting Concrete with recycled aggregate (RSCC) and SCC with recycled aggregate incorporating steel fibres (SFRSCC) . SCC is defined as a highly workable concrete which flows by its own weight. Sustainability of SCC can be improved by replacing mineral aggregates by industrial waste like rubber, recycled aggregate, granite powder etc. An experimental investigation was carried out on the stress strain characteristics of SCC by partially replacing 25, 50, 75 and 100 % of coarse aggregate by recycled aggregate (RSCC) for varying design strength 30, 40, 50 MPa under monotonically increasing axial loading. The behavior of SCC with 100 % recycled aggregate incorporating steel fibres with different volumetric ratios is also explored. A total of 72 cylinders were prepared to develop a stress strain model for RSCC and SFRSCC. The results were compared with the existing models used for SCC and recycled aggregate and it indicates that Saenz model was found applicable for finding the stress block parameters. The proposed parameters were found to be lesser than the values for normal concrete specified by IS 456 and that these parameters could be used to determine the flexural strength of members made using the above composites.

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Equivalent stress-strain law for embedded reinforcements considering bond-slip effects

Engineering Structures ◽

10.1016/j.engstruct.2018.03.045 ◽

2018 ◽

Vol 165 ◽

pp. 247-253 ◽

Cited By ~ 2

Author(s):

José Ramón Díaz de Terán ◽

Vladimir G. Haach

Keyword(s):

Equivalent Stress ◽

Stress Strain ◽

Bond Slip ◽

Slip Effects

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Equivalent stress block for normal-strength concrete incorporating strain gradient effect

Magazine of Concrete Research ◽

10.1680/macr.2012.64.1.1 ◽

2012 ◽

Vol 64 (1) ◽

pp. 1-19 ◽

Cited By ~ 8

Author(s):

Jun Peng ◽

Johnny Ching Ming Ho ◽

Hoat Joen Pam ◽

Yuk Lung Wong

Keyword(s):

Strain Gradient ◽

Equivalent Stress ◽

Normal Strength Concrete ◽

Strength Concrete ◽

Gradient Effect ◽

Normal Strength ◽

Stress Block

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Strain gradient effect on the behaviour and strength of masonry

Canadian Journal of Civil Engineering ◽

10.1139/l07-055 ◽

2007 ◽

Vol 34 (10) ◽

pp. 1208-1215 ◽

Cited By ~ 2

Author(s):

J Hou ◽

Y Liu

Keyword(s):

Compressive Strength ◽

Strain Gradient ◽

Load Capacity ◽

Equivalent Stress ◽

Block Code ◽

Linear Elastic ◽

Gradient Effect ◽

Compressive Stresses ◽

Block Based ◽

Stress Block

Twenty-four masonry prisms, including both grouted and hollow specimens, were tested to investigate the strain gradient effect on masonry compressive strength. Results showed that a reduction in load capacity as a result of an increase in eccentricity is more significant for grouted prisms than for their hollow counterparts. At a relatively large eccentricity to thickness ratio, e/t, hollow prisms attained a higher ultimate load than grouted prisms. Compressive stresses calculated at the extreme fibre using linear elastic analysis showed that the strain gradient effect increases with an increase in the eccentricity for grouted prisms, whereas the increase is marginal for hollow prisms. Coefficients for the equivalent stress distribution block, based on experimental stress–strain curves, were obtained for prisms under eccentric loading. An evaluation of the rectangular stress block used in both the American design code and Canadian design standard showed that the rectangular stress block provides an adequate and somewhat conservative estimate of masonry compressive strength and this conservatism increases as the strain gradient effect increases.Key words: masonry, strain gradient, eccentricity, compression, prisms, rectangular stress block, code, standard.

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