Cast-in-Place vs. Mechanical Anchors

[brquigle]

Does anyone have a feeling on the cost impact (per anchor) of installing cast-in-place anchors vs. doing it later with mechanical wedge anchors? Strength constraints aside, The testing requirements on the latter have to factor in, as well as the additional cost of the material itself. But is the setup time of the cast-in-place a much bigger portion?

 

[ukengineer58]

I think post drilled resin is more expensive. Plus they need to be load testoed. It depends on the application and quantity.

 

[Ron]

brq...consider also the cost of getting the cast-in-place anchors in the right place and the inspection costs necessary to verify.

While the cost of getting them in the right place should be included in the bid, often this is an item that is glossed over and then short-cut in the field. If done properly it requires proper location, proper templates and proper anchorage of the templates against movement during concrete placement.

 

[TXStructural]

Constructibility is a huge issue, but I have not ever had a contractor suggest they would prefer to use post-installed anchors. And when many columns require deep embedment (lateral braced frames, etc.), 2-3-4 ft holes would be a problem. Also, columns could not be erected until the anchors are set, requiring multiple trades to coordinate their activity, and would result in delays (compared to traditional placement of anchor rods.)

 

[ErZaZee]

Post-installed anchors are usually used for lightweight structures.

 

[ukengineer58]

As tx said there are logistical and health and safety issues for all but small lightweight structures