30 Apr Considerations for concrete quality
We would like to share some basic info with you and point out a few questions everyone should consider.
Are other companies supplying 4000 psi mix? Some company may specify 4000 psi and then orders
cheaper 3500 psi mix. That puts a little cash back in their pocket. There are different quality concrete
suppliers to order from, with lower quality concrete out there to be had and used. Our suppliers are
used by large commercial type building construction and highway work. These suppliers have quality
control involved as each truck leaves. Concrete can end up with cheap fly ash as an additive or shale
rock instead of hard durable limestone. Lack of quality control can result in the wrong ingredients.
Cheap concrete can be ordered from a supplier more than 1 hr. away and have it trucked, heating up
in the truck, to anywhere you want it to go. Did you know concrete should be placed at less than an
internal temperature of 90 degrees? Ideally around 75-85 degrees. Mix traveling in a truck gets hotter
as the mix produces a chemical reaction, as it begins hardening. Internal temperature of the mix of
over 95 degrees means the concrete is even too hot to finish properly. Time of mixing to on the
ground and being finished is a max of 2 hrs. By all specifications. Within that time of 2 hrs, finish
means, what you will see-done. Most of our suppliers use well water when the ambient temperature
is extreme. Well water keeps the concrete internal temperature lower, slowing down the curing
(hardening) of the mix. Concrete that requires a lot of water thrown on while the finish is being
achieved weakens the surface to endure longevity. It can look fine for a few years, but the surface
will begin to flake and pop. Ambient temperature driving the concrete mix temperatures up requires
additives to the mix, are the others taking that precaution, Shamrock does. Is air being added as
required for all outside mixes? Are they using control joint spacing standard practices, in order to
minimize any premature cracking?
Please use our Reference Map Web site feature to drive by and view an older driveway and see
how the concrete its looking after a few years. That’s the real value, not short term being the
day its poured or just a few weeks later.
Research on the Internet and through engineering practices will confirm all what is mentioned here.
It’s all honesty and integrity by the contractor and his knowledge of right and good for his reputation.
All of the above weighs heavy on the short to long term performance of the concrete.
Methods by Shamrock, Regarding seal quality and applications; there are spray on seal
applications applied the day concrete is poured or a method of a 2 coat rolled on seal, applied within
a few days after installation. Rolled on does in fact add cost. Shamrock can price any method of seal
as an addition to your project.