I am pouring a new slab for my RV. It will be outside in a covered shed. The slab is 40' X 50' 6" deep. My queston is can I put the Dowels in place before I pour and not have to drill them. I have 6 areas to pour and breaking it up into 2 pours 3 sections each day.

Hi paul and welcome to AMHD, when you say "dowels" if you mean rebar to tie the sections together? Then yes you can install it first. Good luck

Are you talking about installing anchor bolts or straps for the wall plates?

Thanks for the response. I am new to this and learning. The concrete slabs are separate and I was going to tie them together and allow for expansion with out cracks. I found that you could drill one side and put rebar and then pour other slab. I think that allows the slab to contract with out moving. I was wondering if I could put the dowels in before I poured.
I am not even sure this is needed. Is just using the rebar for expansion joint sufficient for decreasing cracks. I am probably over thinking this.

These smooth dowel types of joints have been used in highway concrete paving at contraction joints (every approx. 40 feet measured in the direction the vehicle travels) for a long time and were referred to as load transfer devices. They were normally placed at mid-point of the depth and supported on chairs (metal supports holding them in correct position-the chairs being embedded with the pour. Usually, both sides of the joint were placed in the same operation (continuous) and a joint sawed within about 12 hours max.
If you are just pouring one side of the joint per pour, you could probably build a wooden support sitting on the grade of the second pour, then remove for 2nd pour. The smooth dowels are usually greased to increase movement.

Paul over time all concrete is going to crack no matter what precautions or methods you use. Anytime I have added a concrete slab next to an existing slab I always drill 3/4 holes with a hammer drill and drove in pieces of rebar a foot long (6 inches into the old slab). This will tie the sections together and keep them level, and prevent separation.

If I were in your place I would pour it all at once and have expansion joints cut across it every 20 feet.

Hope this helps

Yes I am pouring smaller section to be able to handle it with two people. I am adding a board to separate the pours for expansion. I was just reading and found out about the dowels. Never could find them at the Box stores so thinking I might make my own using pipe and rebar with grease in between. I am more concerned with moving up and down then side to side. The dowels sound like they would help with both.
Any comments on my home make dowel working or being a waste of time.
Need to change my name to the “weekend carpenter”.

The last slab I poured was 20' wide by 28' long using the 3/4 inch rebar at two foot intervals to tie it to the adjoining slab. I dug 24" deep footers and one 24" deep beam which ran length wise. This was 4 years ago and this addition has not moved. There have been some surface cracking which is normal but nothing serious. I don't think your going to accomplish much by using pipe and rebar to make a sliding connection. I would not use wood between your sections, it will rot away then you'll have fill the gap with some sort of filler. If you've never poured concrete before I would highly recommend having some experienced help, or spend the money and hire someone to do it for you.

I should have been more clear with the use of board. I am using fiber board, I think it's called, to separate. Thanks for the help all. Not done building so might ask more.