Design Aspects of MIVAN
i) Conventional RC columns, beams, and slab
(RC moment resisting framed structure)
ii) RC load-bearing walls and slabs.
In the case of RC moment-resisting framed structures, the horizontal forces due to wind or earthquake are resisted by the frames resulting in the bending moments in columns to resist bending moment and vertical loads would be more than that required to resist vertical loads without bending moment. Similarly, additional reinforcement will be required in beams at supports.
In the case of RC load-bearing walls, monolithic casting of slab along with RC walls results in a box type structure, which is very strong in resisting horizontal forces due to wind or earthquake. In view of large depth of shear walls, the resulting stresses due to bending moment and vertical loads are smaller and in many cases, concrete alone is capable of resisting these forces.
On evaluating these alternatives, it is seen that the beam column frame system in
i) Performs poorly against earthquake forces
compared to RCC wall and slab construction. Recent changes in the IS Codes, as
well as recommended good practice demand provision of additional reinforcement
comply with ductility requirements.
ii) The sizing and detailing of columns needed to
be –that they are 20% stronger than beams they support.
Economics of Mivan Formwork