Leaderboard

Waqas! You should remember that we have to satisfy all applicable DESIGN CODE requirements, while designing a structure. IMO, in case of special moment frames subjected to bending and axial load (required in seismic zones 3 & 4 or SDC D, E & F), ACI 318-08 Section 21.6.4.4 is certainly applicable, and HAS TO BE SATISFIED. Chapter 29 of PCA Notes on ACI 318-08 contain very elaborate examples on how to make design calculation for earthquake resistant structures. You might like to have a look at Example 29.3 section 5, describing in detail the method of calculating transverse reinforcement (hoops, ties etc.) Regards.

Assalam-o-alaikum! Dear colleagues! While carrying out structural steel design according to AISC code, we need to specify materials to be used for construction of various structural elements, with reference to relevant ASTM standards. Which material we use, will depend upon loading conditions to be considered, structural framing system adopted and other structural design requirements. But the question is, are we specifying these structural steel materials correctly? The following article, published in Modern Steel Construction, throws light on this issue and helps us understand how to specify materials for structural steel design per AISC properly. http://msc.aisc.org/globalassets/modern-steel/archives/2015/02/steelwise.pdf Regards.

Asslam-o-alaikum! Rana Waseem and Sir Umar! Thanks for updation and clarification. The complete picture with reference, for AISC structural steel design code users, is as under: According to AISC Steel Construction Manual, 13th edition 2005 (Part 16-1 Section A3, Subsection 4), materials conforming to following ASTM specifications are approved and, therefore may be used for 'Anchor Rods and Threaded Rods' in structural steel designs carried out as per AISC 360-05 code. ASTM A36/A36M ASTM A193/A193M ASTM A354 ASTM A449 ASTM A572/A572M ASTM A588/A588M ASTM F1554 The preferred material grade for Anchor Rods is however ASTM F1554 (as Rana has also indicated above.) AFA implications of 'Slippage Test' results indicated in your bolt test reports is concerned, you may use following options: a. Go through applicable ASTM standards b. Do an internet search for the relevant requirements c. Get the help of UET Lahore laboratory incharge, who prepared/issued the test report, to know what is the acceptance criteria, and whether actual result is acceptable or otherwise. He might possibly help you classify your bolts as well. Regards.

Rasheed! Most commonly used anchor bolts in our country, fall under ASTM A307 and A36 specifications, although bolts conforming to other material specifications (like ASTM A572, A588 etc.) may also be used. Moreover, in engineering practice, orders for supply of anchor bolts for a particular work are always made with reference to one of the ASTM specifications, depending upon actually required grade of steel for the anchor bolts as per structural design. You should also order the bolts (and other structural steel sections) in in the same way, in order to make sure you get specific quality material. And, should also obtain guarantee of their conformation to relevant ASTM specification, from the supplier. Keeping in view your provided information, tested bolts MAY qualify for classification under ASTM A307 or A36, PROVIDED your bolts conform to ALL the structural requirements described in relevant specification. Regards.

Is this a MUST check to perform? What If I just provide ratios obtained from ETABS and dont satisfy it? From Etabs I got much lesser required rations i.e. 2 legged #3 @ 4 inch is satisfying my etabs required ratio. But ETABS MANUAL of concrete frame design CFD-ACI-318-08, Topic 3.4.4.3 says "The column shear reinforcement requirements reported by the program are based purely on shear strength consideration. Any minimum stirrup require- ments to satisfy spacing considerations or transverse reinforcement volumetric considerations must be investigated independently of the program by the user." ACI 318-08 R21.6.4.4 says "Instead, Eq. (10-5) and (21-4) are required, with the intent that spalling of shell concrete will not result in a loss of axial load strength of the column. Equations (21-3) and (21-5) govern for large-diameter columns, and are intended to ensure adequate flexural curvature capacity in yielding regions."