New concrete driveway.... questions.

[mrsilv04]

My folks had a new concrete driveway poured on Wednesday. 4" thick, using the fiberglass mixed concrete.

Instead of coming back and cutting it, they went ahead a struck it, so it more matches the era of their late 1960's ranch house (that was a nice touch).

How long until it can be driven on, and when should it be sprayed and sealed with a clear silicone sealer?

 

[JHZR2]

Originally Posted By: mrsilv04
Instead of coming back and cutting it, they went ahead a struck it, so it more matches the era of their late 1960's ranch house (that was a nice touch).



Can you explain what that means? We are considering going concrete to replace an ageing and breaking asphalt driveway as I think it will look more correct for the house.

 

[strongt]

Good rule of thumb is 7 to 10 days. The concrete takes a full 28 days to cure completely.

As for striking the concrete, they just make the indentation lines with a hand tool for where the expansion joints will be. Instead of taking a saw and cutting the expansion joints in. I like the look of saw cutting better.

 

[bladecutter]

We just had out driveway, walkway and rear steps done last month, and it was 7 days before we could put a car on the concrete. The longer you wait, the less likely you are to have any issues.

BC.

 

[JHZR2]

Originally Posted By: strongt
Good rule of thumb is 7 to 10 days. The concrete takes a full 28 days to cure completely.

As for striking the concrete, they just make the indentation lines with a hand tool for where the expansion joints will be. Instead of taking a saw and cutting the expansion joints in. I like the look of saw cutting better.


All concrete by us is poured in smaller blocks, so that there is a natural expansion joint between each one (usually filled with some brown-black strip).

Very interesting, thanks!

 

[mrsilv04]

They struck the slab with tools, as that is how it would have been done in the late 60's, versus taking a gasoline powered saw to cut it.

I'll try to get some pictures posted of it.

 

[JTK]

Yep, hand-cut as opposed to saw-cut joints are more popular. Faster and easier to do.

I just had some concrete work done as well. Replaced an old rotted 12'x16' wooden deck off the side of my house with concrete. Was less $ than I had expected. Love it.

Joel

 

[MNgopher]

At least 7 days before driving a car on it is preferable. Generally, the longer you can wait, the better.

Not a bad choice having the hand struck joints to match. I prefer the saw cut for a variety of reasons, but when matching it makes sense.

As far as sealants go, read the information on the product you plan to apply. They will vary greatly. The sealant I chose (and was recommended by my installer) allowed for application at 28 days. I sealed mine to minimize salt intrusion problems in the winter, as I had a late summer pour.

 

[Donald]

No salt in winter the first winter, so I was told.

 

[MNgopher]

Yep, 1 year before any deicing salt could be used. I don't use any myself. My concern was the deicing salt from the street that ended up on the driveway from snowplowing and what my vehicles dragged along with them and deposited.

 

[Carbon]

Keep it moist. Cover it with plastic if necessary. I don't know how long to wait. A week sounds good.

 

[Stu_Rock]

Originally Posted By: JHZR2
Originally Posted By: mrsilv04
Instead of coming back and cutting it, they went ahead a struck it, so it more matches the era of their late 1960's ranch house (that was a nice touch).
Can you explain what that means? We are considering going concrete to replace an ageing and breaking asphalt driveway as I think it will look more correct for the house.
That's an odd way to phrase it, I think. Perhaps a regionalism? If I understand correctly, it's "hand-tooling of control joints." "Striking (off)" is to me the leveling of the top surface.

 

[MNgopher]

If coated with a curing compund, there is no need to keep it moist or cover it with plastic. Most concrete is done this way now (at least it is here).

 

[badger05]

Originally Posted By: Stu_Rock
Originally Posted By: JHZR2
Originally Posted By: mrsilv04
Instead of coming back and cutting it, they went ahead a struck it, so it more matches the era of their late 1960's ranch house (that was a nice touch).
Can you explain what that means? We are considering going concrete to replace an ageing and breaking asphalt driveway as I think it will look more correct for the house.
That's an odd way to phrase it, I think. Perhaps a regionalism? If I understand correctly, it's "hand-tooling of control joints." "Striking (off)" is to me the leveling of the top surface.


+1 This is the terminology that I am also familiar with. Also, 7 days should be adequate, especially if they just have your typical personal vehicles to drive across it. Also +1 on the advice to not use any deicing salt for the first winter or two.

 

[Shannow]

Originally Posted By: strongt
Good rule of thumb is 7 to 10 days. The concrete takes a full 28 days to cure completely.

As for striking the concrete, they just make the indentation lines with a hand tool for where the expansion joints will be. Instead of taking a saw and cutting the expansion joints in. I like the look of saw cutting better.


Not quite, concrete is specified at it's "28 day strength", which means the strength that it will attain at 28 days (say 35MPa for general duty)...it will get stronger with age...greater or lesser on how it is/was made...it will be a lot more than half way "strong" within a week...eg.

100 year old concrete had large cement particles, and continued to strengthen with age to some amazing properties. Modern, finely milled cements get to their 28 day strength and don't go much further.

The old stuff had great capacity to restore cracks due to having more active material to heal them, modern not so. Many of the buildings that were built in the 80s, 90s, and 00s will be rubble long before the stuff built from the 40s.

The tooled grooves are designed to initiate a crack site for when the slab moves, so it follows the bottom of the groove rather than finding it's way across the slab.

A proper expansion joint, as JHZR2 says is usually a bitumen/fibrous divider installed between slabs.

dampness and exposure to the atmosphere (old sheets rather than plastic) helps make a better slab.

 

[mrsilv04]

Here are the pictures of the new driveway/patio combo, along with some work that I did around the edge with some recycled pavers, and a little work around the post lamp as well.

Also, is a picture of the troweled (old school) joints in the concrete. This is how it used to be done, before they decided to do it the easy and no-skill way of cutting in the joints with a saw.

 

[JHZR2]

Awesome. Did you consider going with aggregate? That's what our town has mostly (1900-30s, but I imagine the sidewalks were all installed in the 50s or 60s).

How long is it going to take to do the whole job?

 

[mrsilv04]

It's done, as far as the concrete work.

The asphalt driveway leading up to the concrete pad is about the length of a football field. It stays right where it is.

 

[tom slick]

Around here those are referred to as a "deep joint". They are still common around here.