If you do choose to damage the threads, keep in mind that this will prevent the adjustable portion from rotating only in the direction to make the column shorter. One will still be able to rotate it in a direction to lengthen the column, something that will be useful for any future adjustments...
I was taught early on in my career that whenever a problem arises, the best option is to address a resolution quickly. In the end, it will be the cheapest, most efficient, most ethical option. Will it cost money... Likely... But much less if left until an issue arises later. Get everyone to a...
ajk1,
From my days as a junior engineer, I completed a fair number of bond tests using a LokTest machine. I believe our specifications called for a minimum 1.0 MPa bond strength, but admittedly this was for concrete repair patches and bonded toppings that weren't necessarily required to be...
In the Ontario Building Code, which likely has similar wording to the NBCC, it calls for a "specified" load of 1.0 kN. The key word being 'specified'. When you look at various references in the Code, the specified loads are then factored as per the Code. In your example, the 1.0 kN specified...
I have designed perhaps a dozen large complex sculptures and have had the same question re deflection as well. In the end, my thought process determined that deflection limits are not important, as long as the sculpture is appropriately designed for strength. However, I do agree that large...
RISA, as well as several of the other companies have shape building modules that you can use to make odd shaped cross sections and then import them into the analysis programs. Typically they are an add on module that you need to purchase above and beyond the basic package. I believe that you can...
Depending on the magnitude of the load, yes the beams may need some lateral restraint to the compression flange. However, the span is small and the Lu of a W8x14 is about 1930mm, which looks to be less than the distance support to support. I would typically select a beam that requires no lateral...
kmead,
Re 2. and 3., this information can be determined from an investigation, although the investigation has to be done quite delicately. After locating a tendon, typically on the underside (so midspan so it is close to the underside of the concrete), get an experienced contractor to carefully...
ajk1,
I am glad to have been of help. They should be providing you with two resistance numbers, one for the coil of wire they are using for the half-cell equipment and the other for the total resistance. As long as the (total resistance - wire resistance) is less than 5 ohms, things should be...
kmead,
Some preliminary thoughts/questions on what could become a complex rehabilitation.
1. What is the cause of the corrosion? De-icing salt or other?
2. Bonded or unbounded tendons?
3. What is the condition of the grease, if unbounded? Emulsified? Any water in sheaths?
4. Any tendons...
ajk1,
Please see attached excerpt from MTO's Structure Rehabilitation Manual. Perhaps this answers your question, if not, I can dig deeper.
http://files.engineering.com/getfile.aspx?folder=39ac8ec1-2266-4ded-89bc-d3b15fa528f9&file=halfcell.pdf
Ajk1,
I will dig a little deeper over the next few days and see if I can come up with something more concrete. Perhaps the OSIM, Ontario Structure Inspection Manual.
I also remember an in house form we used to fill out every half cell survey. That's going back a few years, but I was working...
ajk1,
I have not done half cell tests in quite a few years, but do remember that we always checked resistance between two core locations, where the cores were taken directly over rebar. We often were 100 ft or more apart. I believe we checked the resistance readings against either the ASTM...
I would look at limiting the deflection to
L/360 for snow/live load
L/240 for total load
and also consider limiting maximum deflection not to exceed 1".
This has worked very well for me in the past in high end residential. Tract homes have somewhat less strict criteria.
I often have young...
In Canada I believe the durability, i.e. cover, etc.. requirements are governed by the CSA S413 design standard, which is an add on to A23.3 and A23.1 specifically for parking garages. The clear cover you are required to have is stipulated in this standard and will vary depending on what type of...
