Different concrete gred for beam and column 1

[LewisLiew]

Vertical member like column and wall G40 while hor. Member like slab and beam G30.
How to cast beam? Is that possible to cast beam and column's rebar together?

 

[hokie66]

You cast the column to the bottom of the beam, then the beam, then the column above. Don't try to cast them together, because that leads to plastic settlement cracking.

 

[LewisLiew]

Can I just concrete the column till height of beam with G30 together with beam eventhough column required G40? My consultant want us concrete separetely column till height of beam with G40.

 

[hokie66]

You have to use 40MPa in the column, then at least 30MPa in the floor. There are code provisions/rules, which you should read and understand, about transmission of column force through a floor of lower strength. The principle is that if the floor concrete is restrained, it therefore can bear the higher stress. But if your consultant has specified the two strengths, he should have confirmed that the arrangement is satisfactory. But above all, don't try to cast them together.