Need a book? Engineering books recommendations...
RE: zonolite topping[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: <seaint(--nospam--at)seaint.org>
- Subject: RE: zonolite topping
- From: <SEAInt05(--nospam--at)lewisengineering.com>
- Date: Mon, 16 Aug 2010 12:56:21 -0500
Thanks for your response. I appreciate your input.
The armor edge is what got me thinking about the detail I suggested below. I’ve used an armor edge on industrial warehouses in ailse but it has always been with enw concrete on earch side. This one has existing concrete on one side and new on the other.
I got to thinking about my detail and decided I didn’t like it. I can’t use an inverted steel Tee shape because the existing slab thickness will vary. It may be slightly above or below the top of slab so I can’t fix it to a horizontal plate below. So now I thinking I still would like a steel plate across the joint on the bottom of the slab and then need to figure out a way to armor the edges between an existing slab and a new slab. As you mentioned below, PNA has an armor edge product, but my concern is the structural topping slab is only 3” thick. Perhaps I can adjust my detail to use it somehow.
I need some help remembering an old roofing system, Then I need some help with a precast TEE topping system.
First, the roof system. I know I’m getting old when I can’t remember the way we did it when I got out of school. I guess it happens when you pass the 50 mark. I have trouble remembering a lot of my old projects. But I digress. . . . I recall back in the 80’s there was a zonolite roofing system that was used. I recall the metal deck application used vented deck, insulation board and zonolite topping. I recall the insulation board had holes in it and was put down over the deck. The zonolite was poured, filling in the cracks and holes, creating the roof slope, etc. Then it all was covered by a roof membrane. I recall a similar system on precast hollow core plank. I can’t find any information on this. I guess I’m not googling the right words.
Now the second issue, TEE topping. This is what caused me to recall the first. I’m working on a project, oddly enough constructed in the 80’s, where the TEE was sloped and an insulation board and zonolight topping was placed on it to level the surface. The zonolite thickness varies from 4.5” to 12”, over a 60 feet length. Then a 3” NW concrete topping was added for the floor. The area is a pallet storage area with forklift truck. The slab has been cracking and multiple repairs made. Sometimes the repairs included going all the way down to the top of TEE and pouring back NW concrete and sometimes the repair has left the zonolite system in place. Usually the repair begins to crack again at the edge and just grow bigger. I’m thinking it might be an issue with the difference of depression the forklift truck makes as it rolls over the joint area. This is kind of like a slab on an elastic foundation. If one area does not deflect down like the adjacent area then there could be bounce as the tires roll over it, causing the slab to crack near the edge. This would be pronounced where the zonolite was removed and NW concrete was poured back down to the TEE surface.
My thought for the next repair is to try to maintain a constant elastic bearing for the topping slab. I propose to cut the topping into a square with a saw. Replace any damaged zonolite. Fabricate an inverted steel Tee from plates and wedge the flange of the Tee under the existing slab. Then a new 3” topping is poured and bears on the Tee and zonolite. I see this as distributing the wheel load over the crack onto the zonolight. I would like to fill the gap between the existing slab and the steel Tee with an epoxy grout. One problem I have is that they tried to use an epoxy on a previous patch and apparently the epoxy melts the zonolight, kind of like gas on Styrofoam.
I’m looking for anyone who can give some insight into this repair procedure. Then I’m looking For anyone who can help me get some sleep by helping me recall this outdated roof system.
found in this incoming message.
- Prev by Subject: RE: zonolite topping
- Next by Subject: RE: zonolite topping
- Previous by thread: RE: zonolite topping
- Next by thread: RE: zonolite topping