RobA
Platinum Member
I had concrete ramps poured for my barn. I believe they are 5" thick. How long before I can drive something like an ATV over them? How about a tractor?
Good. .. forgot to mention that.Concrete does not dry, it cures. [Moist curing for 28 days will double the final strength of concrete vs. leaving it unprotected in air.]
Moist curing for 28 days will double the final strength of concrete vs. leaving it unprotected in air.
what is your source of this information...?
the compressive strength of concrete is relative to the water/cement (portland) ratio...keeping it wet will enhance the curing but it will not likely "double the strength"...
Curing Concrete | Concrete Technology | Portland Cement Association (PCA)
You are correct. I misread Figure 1. Moist cure for 28 days only increases concrete strenght by about 50%. You have to moist cure for a year to double the strength.
Pls elaborate on this statement. Exactly what are you saying.?The bottom line is that 90% of all breaks will reach 80% or greater at 7 days and 125% at 28 days. It is not unusual to see breaks up to 6,000 PSi at 28 days.
Now this is not your usual run of the mill concrete and we are required to have a plant inspector at every batching, but it is typical for most concrete.
They say the Hoover Dam is still "curing".
Here's good article for all to enjoy.
CONCRETE: HARD FACTS. DURABLE STRUCTURES
Pls elaborate on this statement. Exactly what are you saying.?
larry
Pls elaborate on this statement. Exactly what are you saying.?
larry
The "breaks" he's refering to are test samples that are taken at the jobsite, cured, and crushed at specific cure dates in a lab. MikeD74T
Thanks!Concrete test cylinders are typically 6" diameter by about 15" high. They are prepare by a certified inspector according to ASTM specifications. At 7 days they are placed in a hydraulic press and crushed. The pressure to crush them determined the compressive strength of the concrete.
Ninety percent of the 7 day breaks will reach 80% of the design strength. i.e. 4,000 PSI design mix will result in a 3,200 PSI strength at 7 days.
A typical cylinder will take 40 to 50 tons of force to break it.