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http://dx.doi.org/10.4334/JKCI.2011.23.1.039

Effect of Partial Prestressing Ratio and Effective Prestress on the Flexural Behavior of Prestressed Lightweight Concrete Beams  

Yang, Keun-Hyeok (Dept. of Architectural Engineering, Kyonggi University)
Moon, Ju-Hyun (Dept. of Architectural Engineering, Mokpo National University)
Byun, Hang-Yong (Korea E&C. Co. Ltd.)
Publication Information
Journal of the Korea Concrete Institute / v.23, no.1, 2011 , pp. 39-48 More about this Journal
Abstract
The present investigation evaluates the flexural behavior of pre-tensioned lightweight concrete beams under two-point symmetrical concentrated loads according to the variation of the partial prestressing ratio and the effective prestress of prestressing strands. The designed compressive strength of the lightweight concrete with a dry density of 1,770 $kg/m^3$ was 35 MPa. The deformed bar with a yield strength of 383 MPa and three-wire mono-strands with tensile strength of 2,040 MPa were used for longitudinal tensile reinforcement and prestressing steel reinforcement, respectively. According to the test results, the flexural capacity of pre-tensioned lightweight concrete beams increased with the increase of the partial prestressing ratio and was marginally influenced by the effective prestress of strands. With the same reinforcing index, the normalized flexural capacity of pre-tensioned lightweight concrete beams was similar to that of pre-tensioned normal-weight concrete beams tested by Harajli and Naaman and Bennett. On the other hand, the displacement ductility ratio of pre-tensioned lightweight concrete beams increased with the decrease of the partial prestressing ratio and with the increase of the effective prestress of strands. The load-displacement relationship of pre-tensioned lightweight concrete beam specimens can be suitably predicted by the developed non-linear two-dimensional analysis procedure. In addition, the flexural cracking moment and flexural capacity of pre-tensioned lightweight concrete beams can be conservatively evaluated using the elasticity theorem and the approach specified in ACI 318-08, respectively.
Keywords
pre-tensioned beams; lightweight concrete; flexural capacity; ductility; partial prestressing ratio;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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