Abstract

This research examines the comparative analysis of theoretical and practical collapse load of a square single panel space frame consisting of slab, beam and column. A reinforced concrete proto type of 3m×3m×3m space frame with a reduction factor of 3 was designed, a model of it constructed and casted with a micro concrete of 1:6 mix ratio. It was cured and crushed after 28 days strength. The micro concrete compressive strength was 7N/mm2 which satisfied average compressive strength of 1:2:4 reinforced micro-concrete. The theoretical collapse load was 21.44 kN. The model was put under load; at 18.3 kN an orthogonal yield line was observed at the slab soffit, as the load increases to 20.3kN cracks were noticeable at the beam/column joints. Further increase in load made the beam/column slab joint cracks much more pronounced. At constant load of 21.96 kN, without adding more load, the deflection on the dial gauge continued to rise, vibration of the structure occurred, until the structure finally collapse at that constant load (21.96 kN). Comparing the theoretical collapse load with the experimental collapse load, the later was 21.96 kN more than 21.44 kN estimated. It was observed that the beam/column joints failed due to shear not due to bending.

Keywords:

Collapse load, compressive strength, micro-concrete, yield line,

References

Competing interests

The authors have no competing interests.

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Copyright

The authors have no competing interests.