Headed studs in grouted masonry
Headed studs in grouted masonry
(OP)
In the ACI 530-11 masonry code, chapter 2, section 2.1.4.3 and following, the equations for the allowable tension and allowable shear have greatly increased since the ACI 530-05 code. I do not have the ACI 530-08 code where this increase originated. Seems the coefficients increased by a factor of almost 3. For example for the tension Bas = 0.6Ab(fy) in the 2011 code and was Bas = 0.2Ab(fy) in the 2005 code. Can any one provide the reasons for these increases? Am I missing something? Thanks in advance. Have a great day.






RE: Headed studs in grouted masonry
Since the ACI code is driven by the Masonry Joint Standards Committee (MSJC), which is a group of different associations, some of which have great laboratories to access when they are not tied up by government and contract research. The progress of the research, testing and report preparation to get acceptable for submittable to the MSJC can take years, so it is not a "knee-jerk" reaction to an idea. After that, it must the accepted by a an authority with the legal ability to enforce it as a code item and not just a standard.
Even a minor change in an ASTM standard can take years to dodge the pitfalls and "little old ladies" (interested parties) or even academics in a consensus standard with balanced representation.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.