Large Expansion Joint Problem

[compressor5]

Alright, this is my first post, but I have looked at 3 dozen threads looking for an answer to this question, and while there was quite a bit of good advice and some answers to my other questions, nothing I read was completely applicable to my situation.

I have a 22'x24' garage built in 1980. It has a urethane sealer over the pad, which I plan to take down with a 7" diamond cup disc and a heavy duty DeWalt Polisher/Sander. Once that back-breaker is complete, I am going to lay down 4 kits of Rustoleum Pro Epoxy Shield Light Gray with an extra 10lbs of flake. Over that 1 or 2 coats of the Epoxy Shield Pro Clear Coat.

The Garage is cleared and ready for prep, but I don't know what to do about the Expansion Joint running down the middle of the garage floor.

Its a 2x4 stuck in the middle of my floor and I want out! I have read in these forums that you don't want to fill them in, but this joint just seems unnecessary in this situation.

What I want to do is one of two things:

1. Reduce the Gap to a 1/4" all the way down one side of the slab by cutting some 1/4" osb, sticking it to one side, and pouring concrete in to fill the rest. Then pull the 1/4" OSB, stick some backer rod in the 1/4" seam, and put a flexible epoxy over the backer to fill in the gap, but allow for expansion and contraction.

2. Fill the whole joint in with some crack resistant cementitious filler and call it a day.

My question is, what product do I use to close down the gap? Some sort of mortar? A special bonding concrete? I would spend a fortune filling this gap with a straight 2part epoxy.

Any ideas would be greatly appreciated!

 

[compressor5]

After my post last night, I decided to go back out to the garage and look at the situation a little bit closer.

I don't have expansion joints on the outside of the pad. Looks like they poured right up to the stem wall with no expansion joint in between. So the expansion joint in the middle is starting to make sense. Although I measured it and it is 2 inches wide...in the hottest part of the summer. There is quite a gap in between the board at this point. I really don't think this joint moves much, and the pad is obviously well cured.

I am not going to attempt to fill in the joint completely, but I do want to close the gap down to a 1/4 inch. And then put a semi-flexible filler material in the 1/4 inch joint to keep the dirt out. It would be ideal to be able to epoxy over this joint.

I still have no idea what the best material is to bond to the pre-existing concrete that won't break the bank. Would epoxy even be the best option for a 2 inch joint, sparing no expense? Has anyone else tried doing what I am doing?

 

[Garage Flooring]

Do you have a tape measure and a camera... Or can you take a picture with something for perspective.