Concrete questions for the expertz

[jerkbait_1075]

Good advice about waiting to finish instead of playing catch up. Not only from the finish appearance but "playing catch up" and working the surface in desperation can lead to a whole nother multitude of problems. Yes this time of year accelerator is an option/necessity. Two things: First if you are using any type of reinforcement steel or wire mesh then I would strongly reccommend a "non corrosive" accelerator. WR Grace Company makes a product called DCI that is a non corrosive set accelerator. There are many other manufactures with similar products. We strictly use WR Grace products. Most ready mixes would simply give a contractor or do it ur selfer Calcium Chloride for a set accelerator. The problem with calcium chloride is that it is corrosive and will eventually "eat away" you re rod or wire mess. The option to steel is to use a reinforcing Fiber mesh. However fiber mesh will also show small fibers in the surface of the concrete. Its personal preference but I like the fibermesh and the fibers are very hard to see and do wear away. Second option. Is to avoid the accelerator all together and use Hot Water in the mix at the time its bathced. Now this can be a difficult task for do it urselfers as Hot water can be a very unpredictable animal and concrete can get "away" from you finishing wise in a hurry. Also if the ground temp is 40-45 or lower, or the aggregate temp of the material piles at the ready mix plant are below that temp you really need to use hot water. If this is an outside slab, or cold storage and you live in an area where temps are going to be at and below freezing routinly from here on out you need to get the process of curing going and keep it going. Your new slab is not going to be safe from the dangers of freezing temps for at least 21-28 days. Keep that in mind. If the temps are going to be low you may want to consider keeping the slab covered. Once finished, straw, styrofoam, frost blankets are all options. However if it is to turn warm or moderatly warm again it is equally important to remove these covers so you dont over heat the curing process.

Concrete is a tricky animal.... Lots of factors at play..... Good luck

 

[booondocker]

... Waiting on concrete to set always yields a superior finished product as opposed to trying to play "catch-up", especially when you don't do it for a living............

This reminds me of my very first concrete job!

I was about 12 years old and my Dad decided to build an extra garage on the 3 acres we lived on.

So we got the footings done, and the block course completed and the day came to do the floor.

It was an overcast day but no rain in the forecast and the delivery truck came and began the pour. We got it done and began to do the troweling and it was looking pretty good.

Then out of now where came some huge rain clouds which proceeded to pelt the surface and pock-marked it to a serious level. There wasn't much we could do and we had nothing to cover the surface with so we stood around and watched. Once the rain quit the sun came right behind it and well....the rest is history....we re-troweled one corner but it was set so hard that it was pretty much useless. We never heard of a power trowel either.

My Dad said, "well, we will never ever have to worry about slipping and falling on that job, will we?" It never cracked, and as far as I know it has stood the test of time...cause it is still there over 50 years and counting.

Life is nothing without a lesson to learn from and sometimes lessons come back to back!

 

[hotwire]

I just wanted to thank everyone for their input on the concrete. We poured it yesterday, and it turned out beautiful. Had a few sprinkles as we were hitting it with the Frezno float dooing final trowelling, but nothing to worry about. I also poured a generator pad for a 22kw genset going next to the shop. Now I need to find the time to build the exterior walls and roof.
Thanks for the advise, Hotwire.