Lap lengths in columns

[Sandman12]

Hi,

I was curious to know what type of lap lengths you allow for in columns?

Where I live we seldom use bars larger in size than 32mm diameter.

Thanks

 

[Trenno]

I allow the bar laps as required by my national design standard.

40db is a good rule of thumb.

 

[MotorCity]

Do you have any reason to provide less than the code required lap lengths?

 

[PicoStruc]

I think the real question is to put compression or tension lap splice.

I my opinion, Tension lap is required to be able to develop moment resistance for lateral displacement capacity (Seismic / Wind)

 

[Sandman12]

That would be for pure compression or compression with some flexure. As a rule we do not use less than 40Ø as well. Our code allows you to go less than that, but you have to provide at least more than the anchorage length. The lap length is obviously also dependent on other factors not mentioned here.

I was just interested to know because if you use #18 bars and 40*Ø lap you end with a splice in excess of 2m long. That is basically two thirds of your floor to floor height. I would imagine it is cheaper to use mechanical splices then.

As I said, not really applicable to something we do here. I was just interested in the type of details you guys do on the other side of the Atlantic.