truss bars
truss bars
(OP)
I have a set of drawings from the 1970's which shows a cast in place concrete beam. The beam is 25-Ft long, 1'-9" deep, and 1'-6" wide. The beam is integral with the concrete slab.
The section thru the beam does not show the reinforcing layout, but there is a note describing the reinforcing as follows:
3-#7 straight-bottom bars
3-#7 truss bars
3-#7 extra-top bars
#3 stirrups @ 4"
Any ideas as to what the truss bars are and where they might be located within the beam? I am sure they are not referring to the shear reinforcing since they specifically call out stirrups. I believe that the truss bars must be some sort of flexural reinforcing, since the beam is under-designed for moment if I neglect the truss bars.
The section thru the beam does not show the reinforcing layout, but there is a note describing the reinforcing as follows:
3-#7 straight-bottom bars
3-#7 truss bars
3-#7 extra-top bars
#3 stirrups @ 4"
Any ideas as to what the truss bars are and where they might be located within the beam? I am sure they are not referring to the shear reinforcing since they specifically call out stirrups. I believe that the truss bars must be some sort of flexural reinforcing, since the beam is under-designed for moment if I neglect the truss bars.





RE: truss bars
thread507-14653
thread507-91262
The bars are bent continuous bars that start out at one end of the span (over the support) as top bars, extend out to about the inflection point or so and then bend down at a diagonal to become bottom bars in the central region of the span, then turn up diagonally at the other inflection point and become a top bar again. Very common in older concrete structures.
So at the supports, you have an As value that is the sum of the bent and top straight bars at that support.
At the midspan, you have the sum of the bent and bottom straight bars in that span.
RE: truss bars
RE: truss bars
Dik
RE: truss bars
RE: truss bars