Ive got a cantilevered conc deep beam with a backspan (2x stories high), and will be providing hanger reinforcement along the cantilevered section, running vertically up from the lowermost slab to the next level.
Can this hanger reinforcement be lapped or does it need to have couplers...
As far as slender column design is concerned (assuming braced column), the moment amplification can often be extremely sensitive to the concrete cover. Even increasing the cover from 30mm to 60mm to account for the joggle in the reinforcement at the slab level can have a significant impact.
Can...
Is this clause only applicable to edge/corner columns that are part of a moment resisting frame building, or edge/corner columns in general?
The SRIA Guide to Seismic Design & Detailing of Reinforced Concrete Buildings in Australia appears to suggest that it is only applicable to OMRF and IMRF...
With reference to section 6.2.3 and 6.2.5 under Structural Robustness in AS1170.0, does the 5% of the value of G and G+ycQ refer to the total vertical load from all slabs above the connection in question, or just the vertical load from a single slab?
When designing key elements for an applied load of 34kN/m2 (such as corner columns on a high-rise) as a way to satisfy robustness and avoid disproportionate collapse, what effective column length do you consider? Is it acceptable to check the column capacity based on a single story height, or do...
How do you assess the crack-bridging ability of a waterproof membrane assuming there are no cracks to begin with (i.e. if the original crack width is non-existent or 0mm)?
A discussion on this can be found in the links below:
1...
Looking at top-down construction with precast plunge columns embedded into insitu barrette piles, with beveled ends to the precast cols where it transitions into the piles - refer below sketch reinforcement not shown for clarity.
Wondering if the chamfered cold joint would create any local...
In developing a strut and tie model, is it necessary to first split the load b/w the concrete and reinforcement and merge 2x models into 1x model?
I came across a worked example of a strut and tie model b/w a column and pile cap (refer attached), where 2x models (representing the load carried...
Punching shear is a clear and apparent mode of failure when the column is poured to the underside of the slab (that is, when the slab bears over the column, as is conventionally seen in most situations).
Does this failure mode also apply if the slab does not inherently bear over the column, but...
In tall buildings with an eccentric core, where gravity-induced long term differential axial shortening leads to the building leaning under its own self-weight, just wondering if the resulting inter-storey drift needs to be added to the inter-storey drift assessed under wind loads? Or if a...
Is there any fundamental issue in opting to design and detail your structure as limited ductile (u=2) under seismic loads, if under the full elastic earthquake load (with u=1) all the walls remain in compression? My understanding is that in order for the limited ductile assumption to be valid to...
I started a thread a couple of years ago seeking some advice on the relationship b/w the overall length of a suspended slab and the need to provide movement joints (link provided herewith for those interested).
https://www.eng-tips.com/viewthread.cfm?qid=446169
Following on from this, I was...
When assessing long term slab deflections, the shrinkage-induced tensile stress due to restraint should be considered, as this reduces the flexural tensile strength (and cracking moment) of the concrete section and increases deflections. I understand the two primary sources of restraint are...
Say we have a 40-storey tower with a 3-storey above grade podium structure and double volume basement. Assuming the overall length of the podium slab does not warrant a movement joint to accommodate thermal and shrinkage effects:
1. Will a movement joint still be required at the interface b/w...
AS3600-2018 and AS1170.4 specifies that partially or fully ductile coupled walls shall be designed with a ductility factor (mu) of 4 and structural performance factor (sp) of 0.67, and that we should refer to the NZS 3101 code for details. Is there any scope to adopt a lower mu and sp for these...
I refer to the new concrete code AS3600-2018 under "Section 11 - Design of Walls, clause 11.7.4 - Restraint of Vertical Reinforcement" - see attached excerpt.
With reference to the last statement, does this only apply for walls that are designed as columns, or for walls in general whether they...
Is there any minimum concrete thickness requirements for deep beam/wall design? Can a single layer of reinforcement be sufficient?
Have so far adopted strut and tie method to justify a 150 thk deep wall with a single layer of reinforcement each way without any stirrups, under gravity loading...
In the new Australian concrete code AS3600-2018, under section 8.6.2.3- crack control by calculation of crack widths, the crack inducing strain calculation (i.e. mean strain in reo minus mean strain in concrete) appears to incorrectly include the long term shrinkage strain.
For end restraint...
I have a couple of questions re: movement joints:
1) When deciding whether or not a movement joint is required in a suspended slab, the overall length/size of the slab is the first thing that is often considered. Is this simply due to the fact that, for a given restrained strain (resulting from...
For the design of deep beams, the general consensus is to use the strut and tie method. As an alternative though, if a finite element model is set up using say SAP2000, would it be acceptable to simply extract the direct stresses from the analysis, and compare it to the max allowable stresses...
