Making A Concrete Slab 8ftx8ftx2in

[Daffy D]

Make sure any type of reinforcement to increase tensile strength is not placed along the neutral axis, but rather near the bottom or top of the slab, depending on how it will bend under loads.

I always thought the reinforcement had to be in the center

So a slab like mine where the weight is from the top should have the reinforcing near the bottom of the pour ?

[katabeachbum]

Make sure any type of reinforcement to increase tensile strength is not placed along the neutral axis, but rather near the bottom or top of the slab, depending on how it will bend under loads.

I always thought the reinforcement had to be in the center

So a slab like mine where the weight is from the top should have the reinforcing near the bottom of the pour ?

one inch/2,5 cm from the bottom

when making 15 cm thick concrete roads, wire mesh is 2,5 to 4 cm from the bottom. load capacity 25 tons/25.000 kg.

[jackr]

<deleted>, he's making a floor for a washing machine not a runway. Op, just tie up some real (5 baht a metre) rebar, bung concrete on top and ask for the thread to be shut.

[longball53098]

<deleted>, he's making a floor for a washing machine not a runway. Op, just tie up some real (5 baht a metre) rebar, bung concrete on top and ask for the thread to be shut.

I agree

[trogers]

Make sure any type of reinforcement to increase tensile strength is not placed along the neutral axis, but rather near the bottom or top of the slab, depending on how it will bend under loads.

I always thought the reinforcement had to be in the center

So a slab like mine where the weight is from the top should have the reinforcing near the bottom of the pour ?

Since the load is mainly human traffic and laundry equipment, I would use 2 layers of steel mesh (dia. 4mm at 10cm square) one inch from both bottom and top. Reason is that load is not so heavy and over the long term, we do not know how the supporting soil will move. Could be that part of the slab may be bending upwards due to loss of supporting soil at the edges (due to erosion?), thus tensile forces may act on the top of the slab.

[katabeachbum]

<deleted>, he's making a floor for a washing machine not a runway. Op, just tie up some real (5 baht a metre) rebar, bung concrete on top and ask for the thread to be shut.

whats the point of using rebars or wired mesh at all if they are not approx an inch from the ground or the top? 600 baht wasted steel in the mud wether its a runway or a laundry slab

[Daffy D]

It's amazing how complicated seemingly simple projects can get :rolleyes:

Just joking Appreciate all the information.

The earth base is 20 year old landfill, same as the house is standing on, so fairly solid. Also my 6in of hardcore has been in place for several weeks with people walking over it so that is well compacted. The 2in slab area is slowly growing deeper as the hardcore settles with all the traffic.

Due to circumstances looks like it will be several more weeks before I'm able to finish the job so by that time I would think the base will be super settled to receive the concrete.

[jackr]

<deleted>, he's making a floor for a washing machine not a runway. Op, just tie up some real (5 baht a metre) rebar, bung concrete on top and ask for the thread to be shut.

whats the point of using rebars or wired mesh at all if they are not approx an inch from the ground or the top? 600 baht wasted steel in the mud wether its a runway or a laundry slab

The point being he doesn't need to know exacting placements or specifications of the tensile strength of this, that and the other. Whether the stuff is on the bottom, top or in the middle of a relatively thin bit of flooring, it will firm it up and hold it altogether. Having it anywhere is better than having it nowhere.

Op, just tie up some real rebar, bung concrete on top and ask for the thread to be shut.

[katabeachbum]

<deleted>, he's making a floor for a washing machine not a runway. Op, just tie up some real (5 baht a metre) rebar, bung concrete on top and ask for the thread to be shut.

whats the point of using rebars or wired mesh at all if they are not approx an inch from the ground or the top? 600 baht wasted steel in the mud wether its a runway or a laundry slab

The point being he doesn't need to know exacting placements or specifications of the tensile strength of this, that and the other. Whether the stuff is on the bottom, top or in the middle of a relatively thin bit of flooring, it will firm it up and hold it altogether. Having it anywhere is better than having it nowhere.

Op, just tie up some real rebar, bung concrete on top and ask for the thread to be shut.

even if thread is shut, rebars in the mud is wasted time and money . lifted from the mud rebars or wired mesh has a purpose, making the concrete significantly stronger