direction 1

Figure 1, the load from the superstructure has to be transmitted to the foundation. The loading spreads at an angle of 45 degree away from the centre of the column. So you bent outwards and not inwards. Inwards will lead to concentration of punching shear at the pad foundation.

That is correct Kiprotich Kiptum

Figure 1

Fig. 1 is correct.

Figure 1 is the correct way of reinforcing. The reason being that it facilitates a proper distribution of load from the superstructure and also the concrete flange is properly reinforced with the bent bars.

both of them correct, but which will be chosen is according to the site situation, as an example if there is many ground beam around the starter bars so use fig 2

Dear Ahmed Hassan Nada , Prashant Mishra , Saurav Kar , Margarita Dajko , Vincent O. Nyangaresi , Kiprotich Kiptum , Morteza Raissi Dehkordi

Thank you all for the responses. However, Let's review the answer to the question provided by the ACI code.

ACI318-19 section (18.13.2.3) says: “if hooks are required, longitudinal reinforcement resisting flexure shall have 90-degree hooks near the bottom of the foundation with the free end of the bars oriented toward the center of the column.”

As we can see, the dilemma was answered by the ACI code, and as I mentioned in the question, figure 1 is just an “old wrong belief.”

figure 1

According to my experience, the correct way is number two (2)

ACI318-19 section (18.13.2.3) says: “if hooks are required, longitudinal reinforcement resisting flexure shall have 90-degree hooks near the bottom of the foundation with the free end of the bars oriented toward the center of the column.”

in my opinion fig. 1 is correct because it also prevents column from toppling under the action of large load from one side

Dear Juan Pablo Peñaloza

Thank you so much for copying the answer.

This is truly eye opening and a shift from norm which we have enforced as right. I've always believed fig 1 to be correct.

I'll research more on the same and revert

Figure 1 because in column foundations we will provide this type of steel rebar to transfer all load in soils

Figure 1

According to the new version of ACI 318-19 the second figure. is correct.

Figure 1

Considering the application aspect 2 Figure is not applicable. It can cause trouble when many reinforcements come together. Therefore, it is healthier in the 1. figure .

Figure No. 1

Fig. 1, por el area de apoyo.

Figure No. 1

No. 1

according to new version of codes, no. 1 is correct

Dear Mehran Shahpari

It was always a question for me until I found out that the new ACI 318 code says the figure 2 is correct.

Figure 1

Fig, 1

Dear Araz Ali , Bestoon Faraj , Ali Moghimi , Alireza Barati , Vladimir Križaić , Abraham Díaz de León Benard

Thank you all for the responses. However, Let's review the answer to the question provided by the ACI code.

ACI318-19 section (18.13.2.3) says: “if hooks are required, longitudinal reinforcement resisting flexure shall have 90-degree hooks near the bottom of the foundation with the free end of the bars oriented toward the center of the column.”

As we can see, the dilemma was answered by the ACI code, and as I mentioned in the question, figure 1 is just an “old wrong belief.”

Dear Abraham Díaz de León Benard

A well-known CODE like ACI won't recommend an approach just by seeing a picture. the logic behind this recommendation is the magnificent work that has done more than 40 years ago by (Nilsson and Losberg 1976).

Generally, I am sure of two things. One is that the ACI code is very protective and does not recommend anything unless after years of research. And second, In terms of findings and new content, the ACI code has always been ahead of all other countries' codes.

No.1

I think no 1 is true all load are In one

absoloutly figure 2

Mr. Mehran Shahpari,

I agree with your point that the force transmission mechanism and the cohesion stress in the bent part of longitudinal bars make better sense to bend the column's longitudinal bars inward. What is important to know here is the absolute difference in the functioning of the two arrangements in terms of force transmission and cohesion stresses. If the difference between the two arrangements (I think so, didn't calculate it) is very small then,

If I am given a choice between the two, I would prefer fig-1.

Why Fig. 1 : Bending longitudinal reinf. as shown in fig-1 would provide more room for concrete around the bent bars which provide better anchorage inside footing. From a construction point of view, the reinforcement cage of the column can be placed with better stability before concreting.

Why not Fig. 2 : Bending longitudinal reinforcement inside will create significant congestion at the bottom of the column, leading poor anchorage of bent portion of bar inside footing.

It is general practice Option 1 is used

please follow ACI code

Fig. Number one is more efficient.

Dear Shahpari,

I think 2nd one is more appropriate, as the hooks bent inwards provides more confinement and increase the ductility.

Regards,

Pravin

Figure 1 is more preferable because the load distribution from columns are in 45 degreesw

Nº. 1

As noted by P. Pravin Kumar Venkat Rao, the correct orientation is inward, towards the core. I quote the excerpt below from Article 8.8.4 of the AASHTO Guide Specification for LRFD Seismic Bridge Design:

"Column longitudinal reinforcement shall be extended into footings and cap beams as close as practically possible to the opposite face of the footing or cap beam."

"If hooks are provided, the tails should be pointed inward toward the joint core"

...it depends on the static function, the jam (Fig.1) or the joint (Fig.2). The joint in this arrangement makes no structural sense

Agreed with Fig No. 1

Hello Mehran Shahpari

The direction of this reinforcement depends on the design, so if the design of the columns points ( hing) is outward, but the design of the columns points ( fixed) be inside