Date

2013

Author

Ghasabeh, Mehran

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Self-compacting concrete is an innovative construction material; its priority to normal vibrated concrete is that there is not any vibration requirement. Bond strength of reinforcement is one of the key factors that ensures the usefulness of any reinforced concrete structure. In this study, 6 full-scale concrete beams spliced at the mid-span were tested under two-point symmetrical loading. Test variables were bottom cover, side cover, free spacing between longitudinal reinforcement, lap-splice length and presence of transverse reinforcements within the lap-splice region. Specimen SC_22_44_88_800 had cover dimensions close to the code limits and had 36db lap splice length. This specimen showed flexural failure. Specimen SC_44_44_44_710 had 32db lap splice and cover dimensions greater than code minimums. This specimen showed yielding primarily. With the increasing loading, however, bond failure occurred with side splitting. ACI 408 descriptive equation for normal vibrated concrete predicted bar stresses of the unconfined specimens produced with self-compacting concrete acceptably well. The predicted values were lower than the measured values to be on the safe side. The error varied between 3.4% and 6.5%. All predictions of the ACI408 descriptive equation was higher than the measured bar stresses of the confined specimens produced with SCC. All the calculated values were unsafe. The error varied between 10.6% and 34.5%. Specimen SC_44_22_22_530_T4 with 24db lap splice length had side cover and spacing between bars 63.3% and 56.7% less than the ACI 318 limits. The calculated bar stress was 21.6% higher than the measured value. The main reason of the deviation was inadequate cover dimensions. In specimen SC_44_22_22_530_T6, number transverse reinforcement was increased to 6 stirrups to overcome the small cover and spacing problem. However, increased number of stirrups inside a small side and face cover caused weak plane and measured bar stress decreased.

Subject Keywords

Reinforced concrete., Reinforced concrete construction., Concrete beams.

URI

http://etd.lib.metu.edu.tr/upload/12615530/index.pdf
https://hdl.handle.net/11511/22364

Collections

Graduate School of Natural and Applied Sciences, Thesis