Hi,
I’m hoping someone is able to point me in the direction of the partial material resistance factor to use for FRP reinforcing bars in concrete elements in Canadian jurisdictions. I’m seeking the value and where it comes from (I.e. A23.3 or otherwise).
Thanks in advance.
SJones:
"Does the HAZ have the same grain structure as the parent material or the weld metal?"
I'm no expert, but thought the grain structure HAZ would be largely similar to the parent material if it was slow cooled. Am I off-base?
I've received a specification from a client asking for CVN testing of the heat affected zone. The parent material is 350WT category 1. By my thinking, if the parent material passes CVN (by definition of the material specification) and the weld has as-welded properties that are tough, then the...
amlinerrichard:
The pipe would need to be 19' in diameter. Is it realistic to find equipment to push that? We could build the pipe, but I'm interested if there's a machine able to push it in Western Canada.
Thanks to all for your responses. Much appreciated.
I don't think there's much to follow up on. I'll post if anything revolutionary arises out of this work.
LI: The groundwater piping system pumps groundwater out of a well and into a holding tank.
Thanks for your reply EdStainless.
It's corrosion on the internal surface. Yes, we've looked at the exterior (painted), the a pinhole through an elbow with iron oxide staining around the pinhole, and the interior from a flange (unpainted). The elbow is not visible from a flange. We then did...
We're in a project to assess the condition of a groundwater piping system following observation of leaking in a line in a building. We've identified it's likely occurring by the microbiologically influenced corrosion (MIC) mechanism, which corroded an 8" sch 40 line (0.322" wall) through in a...
amlinerrichard:
The tunnel is part of material handling system. A conveyor and small adjacent walkway populate the tunnel. We may be able to expose one end of the tunnel. I'll know more following the site visit. Would that be a benefit?
MM:
That's good advice, and I agree I will defer to those with the right experience if ground freezing, or grouting is contemplated. I'll see if I can follow up on my chlorinated-groundwater theory as well. There are certainly chlorides in the concrete, but perhaps they are coming from the...
BUGGAR:
I don't have any experience with grouting. Should I reach out to a grouting contractor to see if this is an option?
I suspect you would need lots of grout thickness for a replace-in-sections approach if the existing concrete is 20" thick. Would the grout tend to consolidate the...
retired 13:
Yes, the tunnel is under a long structure. To my knowledge, there's a slab-on-grade directly above the tunnel. The mining operation stores finished product on the slab on grade with an arch building above the slab. The arches reach well away from the tunnel and slab.
I don't...
Thank you for your quick replies.
retired13:
The source of the chlorides is ground water with high chloride content. The client is mining potash. The weeping-tile drain is clearly not working, and groundwater is draining into the tunnel through wall and roof cracks rather than through the...
I'm a tank engineer, and I do a few tank repair projects each year. I would consider a full-length (18') plate to be field-installed only if the existing plates are outside-stacked. I don't think this is common, but should be field confirmed. If they're centre or inside stacked, then the...
I'm working on a project for a mining operator. They have a reinforced concrete tunnel under a product storage structure, and the tunnel is highly chloride impregnated. Replacement in-kind of the tunnel is an option, but the price tag is rather high and indirect costs from lost production make...
I've been contacted to provide some repair recommendations for a building which has experienced shallow footing subsidence caused by an adjacent sub-grade parking structure excavation. The adjacent lot was excavated and the excavation walls were temporarily supported using anchors and...
BridgeSmith, I won't argue that I have a perfect model. I'm not expecting it to be code-adopted any time soon. I've just found it useful. Could be a different angle, and bond strength is included in the Hilti results.
I will point out the Hilti data I'm referencing is strictly related to...
Thanks for the comments KootK.
Regarding your last comment, I have the following to report:
I've used an approach that I've adopted from the pullout resistance of a cast-in-place anchors with an embedded head. The failure cone (or frustrum) is characterized by a 45 degree cone originating at...
Thank you for the informative image KootK.
This is exactly the image I was going to attach. The one exception is the post-installed anchor's frustrum originates higher on the post-installed (black) anchor if one is back-calculating the Hilti HVU data. From this data, one could conceptualize...
Apologies to all. To be clear, I was referring to fractional anchor bolts/rods (cast-in-place improperly, then replaced using post-installed anchor bolts), and the interaction between post-installed anchor bolts and the longitudinal/unhooked deformed reinforcing steel bars in the pile cap...
I received a call from site, and the cast-in-place anchors I've designed and detailed were embedded too far into a pile cap. The result is we're cutting and abandoning the four cast-in-place anchors (unweldable) in favour of post-installed bars installed using epoxy. The cast-in-place anchors...
