Engine House - Official Work Thread

[Graham Buxton]

I'm not a concrete industry professional, but I found the stemwall forms (the flat panels with "Advance" all over them) shown in Brendan's photos  very interesting.   Mostly I'm familiar with wall forms braced with 2x4 etc  lumber, like this:




If you look (in particular) at the last photo Brendan posted (the inspection pit), you can see that the forms are braced with steel sections.  I didn't quite understand how that all worked, so went looking for more info on Advance Forms. Their website is here:
http://www.advanceconcreteform.com/forms

It appears that our roundhouse engine house is using standard 2' panels, with occasional smaller versions when necessary. There are standard steel corners, two of which can be seen in the inspection pit photo. Here is a closeup from the Advance Forms site:



As you can see in that image, there are 'latches' that hook the vertical steel corners to the 2ft panels.  And the panels similarly hook to each other where the stemwalls are straight.  One can browse the Advance Forms website to see there are a variety of other components available for situations that may/may not be present in our 'pour'.

FYI, the panels themselves appear to be "HDO panels", a plywood core with a 'High Density Overlay' (fibers mixed with resin) which makes a smoother finish than plywood and results in a highly durable surface, compared to standard plywood.

These kinds of forms systems are likely more expensive material-wise than the all-wood versions, but pay for themselves when considering the labor involved to set them up and take them down.   In  the long term, for a forms professional, they cost less than traditional (mostly) wood forms.


Great photos!

[Mike Fox]

There are also small cross tie bars that the latches hook onto, keeping the panels parallel. The ends of those are broken off and the foundation coated below ground with a sealant to repel water. Perimeter drains are typically set up around the outside and inside, and backfilled with stone around the pipe and sand above that to have something that does not hold water. Backfilling with anything else will cause compaction and drainage issues, and could cause cracks in the foundation and floor.

[Jeff Schumaker]

I wonder how the term "garden track" came about.

Jeff S.

The track will be built over what was left of Clarissa's flower garden.

I should have been more clear. Is there a historical context for "garden track" as a railroading term?

Jeff S.

[Bob Holmes]

I was over there today.  What the contractors have done is awesome.  More concrete next week.

Bob

[Mike Fox]

This is a screenshot of how the concrete wall will stick above the floor. This is the strongest way to build the wall, with the floor poured inside of the wall. The only place it would not is at the door openings, where it would be on the wall, as the wall should be lower in that location.

[John Houghton]

Mike,
Thanks for the screen-shot diagram. It really illustrates the foundation/wall construction well.
John

[John Kokas]

Based on prior construction jobs I've managed, if you have the opportunity to use recycled "crushed" concrete for your stone base = do it.  Due to it's broken nature, it has lots of edges to interlock and with the second benefit of it re-solidifying when it gets wet makes for a great base and many times it is cheaper than straight clean stone.

[Benjamin Richards]

I wonder if that re-solidifying bit is right... I thought the curing process is chemical, not physical. If you pulverize cured concrete and add water again, you won't end up with something structurally sound.

Crush-crete is cheap because it is FILTHY. Bottle caps, rubber hose, scrap metal, wood chips, &c. Probably fine for the base but careful using it in the actual mix.

[John Kokas]

Yes, concrete is a chemical reaction, but concrete never fully binds/reacts to 100%.  Normal is about 95-96%, so yes there is a little rebinding but not a full concrete set.  As far as dirty recycle, never happened on my jobs as the site guys knew they would be taking it back out if I caught them and the inspectors knew if they let it happen on their watch they would be working somewhere else.

[Carl G. Soderstrom]

I have used crushed concrete mainly for driveways and shed floors, I don't know about resolidifying
but it sure binds well. A lot better than the local limestone. And it is cheaper.

As for "Garden Track" I always thought it was because they were out in the weeds.     

[Bill Baskerville]

This is a screenshot of how the concrete wall will stick above the floor. This is the strongest way to build the wall, with the floor poured inside of the wall. The only place it would not is at the door openings, where it would be on the wall, as the wall should be lower in that location.

There are a few changes from the sketch as to what is being done on the round engine house.  There is no rea bar in the footers as they were pored over clean stone.  In the walls there is vertical rea bar (set in the footers) every four feet and horizontal rea bar every two feet.  The fill inside the walls will also be stone so there will be no chance of settling.  I believe the outside fill will be gravel.

[Mike Fox]

That was just a screen shot so those that wanted to see what the wall and floors would look like when done.

I would have liked to see rebar in the footers. That clean stone is on top of clay.

[Bill Baskerville]

Mike, I agree with you on the rea bars in the footers.  I was just repeating what I was told by the Concrete guys.

[Mike Fox]

They would know. At least I hope they would steer us in the right direction. My foundation is on hardpan, and I have rebar verticaly every 10 feet and horizontal top, middle and bottom.

[Mike Fox]

Front wall. Stop blocks have been installed where the frost wall drops for the door openings.



Looking from the Front West corner



Looking along the west wall.



East wall looking toward the Turntable