ASD - Reinforced Concrete Beam Design Minimum Reinforcement 1

[eb2404]

I am designing a reinforced concrete beam and the design criteria calls for ASD as the design method. I am used to designing using LRFD, and I am having trouble finding the maximum and minimum reinforcement allowed when designing using ASD. Does anyone know the maximum and minimum reinforcement ratio, or can anyone tell me where I can find this information? Thanks.

 

[Lion06]

Who's design criteria is telling you to design reinforced concrete today using ASD? ACI 318-05 doesn't even recognize ASD. Tell them they are crazy and design using LRFD.

 

[frv]

I may be mistaken, but I think ACI hasn't allowed ASD for decades.

 

[kslee1000]

To me, the min & max steel criteria are there for serviceability concerns, they should be the same for design using ASD (or working stress design method) or USD (ultimate strength design method). Correct me if I am wrong.

 

[civilperson]

There is no explicit upper limit of rho in working stress method, however, the steel reinforcement area is less than 0.75 of balanced condition as a maximum in strength design.

 

[JAE]

The ACI code has the ASD method indicated in Appendix A of the 1999 ACI 318. In this section, under paragraph A.1.3, it states that all provisions of the code in general apply to ASD design except 8.4.

That means that the minimum As required by 10.5, and the maximum As required by 10.3.3 apply.

Also note that in subsequent editions of ACI 318 (such as the 02 and 05 versions) the commentary for section 1.1 (R1.1) states that ASD, as included in 318-99, is acceptable, but is not included in the text of these 318 editions.

Minimum and maximum reinforcing is included in the code to prevent sudden failures of flexural members (read the commentaries for 10.3.3 and 10.5)

 

[frv]

I guess I was mistaken