Search the Community

Salam, I have a Question from seniors,Which detailing of column development length in Raft is correct/better either inward bars or outward bars as you see in images attach. Also give reasons about that. Regards

AOA everyone. Recently I've been very confused with development length and how its provided in different components. I have a few conceptual confusions about it and then a few practical and design aspects of it. I'd really appreciate help on these. Do we provide/check development length for simply supported beams (i.e. check it past the max moment?) Where do we need to check for development length? (in my understanding, we need to check it almost everywhere, where you need to ensure full moment capacity) What is a "critical section" when we talk about development length? (refer to the attached picture) I think its the point beyond which we need to ensure development At a wall-slab joint where both the slab and wall are 8" thick, if #6 bars at 8" c/c need to be developed from the slab into the wall, I found that even with the 90 degree hook, the development length is at least 14". How do you satisfy development length in such a case? For hooked development length ldh, is it the length up to the hook or is the length that includes the length of the hook? For example for a 90 degree hook, would it be 12db+the length beyond the critical section or just the length beyond the critical section up to the hook? I've seen in a few places on the internet that people include the 12db into the development length. This stuff has been eating up gray matter from my brain for a few days now. Any help is appreciated. Thanks!

AOA everyone. Recently I've been very confused with development length and how its provided in different components. I have a few conceptual confusions about it and then a few practical and design aspects of it. I'd really appreciate help on these. Do we provide/check development length for simply supported beams (i.e. check it past the max moment?) Where do we need to check for development length? (in my understanding, we need to check it almost everywhere, where you need to ensure full moment capacity) What is a "critical section" when we talk about development length? (refer to the attached picture) I think its the point beyond which we need to ensure development At a wall-slab joint where both the slab and wall are 8" thick, if #6 bars at 8" c/c need to be developed from the slab into the wall, I found that even with the 90 degree hook, the development length is at least 14". How do you satisfy development length in such a case? For hooked development length ldh, is it the length up to the hook or is the length that includes the length of the hook? For example for a 90 degree hook, would it be 12db+the length beyond the critical section or just the length beyond the critical section up to the hook? I've seen in a few places on the internet that people include the 12db into the development length. This stuff has been eating up gray matter from my brain for a few days now. Any help is appreciated. Thanks!

As salamu alikum, Is it necessary to ensure beam rebar development length (Ldh) or Ld in beam-column joints in intermediate moment resisting frames according to ACI 318-11? Is it mandatory to ensure development length of beam rebar in the column? Thanks in advanced

AOA, i am curious about relation between (splice length and development in RCC Beam Columns and footing) and earthquake zone. if i am using #8 bars then for fc'=3ksi and fy=60 ksi the development length is 71 inch and splice length is 92 inch (almost 7.5 ft). now normally overall story height is 10 ft minus beam depth of 1.5 ft , the net column height remains 8.5 ft . so actually i am providing 2 times of the actual reinforcement in columns. this seems reasonable for earthquake zone 3 and 4 where severe earthquake can occur. for seismic zone 2A and 2B this seems very over design . is there any material available for splice length , overlap and development length zone wise.. thanks

Dear all; I was thinking about at the mid support of continuous beam , if we can stop the top steel only distance of development length into the mid support (not to be continuous ) is that possible ?? As I can simpy think; it is possiple cz the steel to work shall be developed from the critical section and that condition here exist. Discuss please Regards

How can I calculate the required splice length for column? What will be effect on the structure, if someone on site provide the column splice length less than the required length? Will it create problem in load transfer or moment or stress? What is the minimum column splice length can be provided? (With ACI Code Reference) Regards,

Assalam o alaikum. According to ACI 12.5.2, development length for fc' = 3000, fy=60000, for normal weight concrete and epoxy less reinforcement, The required development length comes out to be for #3 = 8.2 inch for #4 = 10.95 inch for #6 = 16.42 inch for #8 = 21.9 inch And if in my case, ACI 12.5.3 is not fulfilled, it means now i have to provide ldh as mentioned above. ldh is STRAIGHT EMBEDMENT LENGTH + RADIUS OF BEND + ONE BAR DIAMETER as shown in figure attached. Now my question is, if in my case, main reinforcement of beam is of #6 and #4, minimum column size required will be 18 inch and 12 inch respectively. Lets say by any means, i can not select #4, #3 bars and size of column where bars are to be terminated is 12 inch, how to fullfil this development length???

Assalam o alaikum, I m getting confuse in wording of ACI 12.10.1 under main heading of 12.10 (Development of Flexural Reinforcement), which says "Development of tension reinforcement by bending across the web to be anchored or made continuous with reinforcement on the opposite face of member shall be permitted." What does it want to say, exactly?