#strutandtie
It's my first time doing a strut and tie problem. It's a short span cantilever situation. I assumed two layers of reinforcing at the top, so with cover and all that I did height as 8" at the top for the tie height.
But how do I assume the height of the boundary strut? I have just marked 8". Should the height of the boundary strut be the depth of compression block or can it be whatever I want for my truss? Depth of Whitney stress block is only 4.7” which is less. I don’t prefer increasing the tension reinforcement.
Can I just do 8” randomly? It’s just to keep it same as the top and the forces from the truss model is ok. Or do I need to do two layers of reinforcing at the bottom too (WITHOUT closed ties per ACI 318-19 section 25.7.2), so the centroid of the rebar can be used as strut force location, to rationalize using 8”?
Please help! | looked at the ACI design Handbook, but they made an assumption (see next pic)
It's my first time doing a strut and tie problem. It's a short span cantilever situation. I assumed two layers of reinforcing at the top, so with cover and all that I did height as 8" at the top for the tie height.
But how do I assume the height of the boundary strut? I have just marked 8". Should the height of the boundary strut be the depth of compression block or can it be whatever I want for my truss? Depth of Whitney stress block is only 4.7” which is less. I don’t prefer increasing the tension reinforcement.
Can I just do 8” randomly? It’s just to keep it same as the top and the forces from the truss model is ok. Or do I need to do two layers of reinforcing at the bottom too (WITHOUT closed ties per ACI 318-19 section 25.7.2), so the centroid of the rebar can be used as strut force location, to rationalize using 8”?
Please help! | looked at the ACI design Handbook, but they made an assumption (see next pic)
