Finishing concrete after an overnight cure
Finishing concrete after an overnight cure
(OP)
The crew showed up yesterday and did the dirt work and formed up for a 34 yard pour for my carport and driveway. At 3 o’clock in the afternoon the first concrete truck showed up and the last truck left at around 7:30pm. The finishers made the first skreet and smoothed it all out pretty good. They were waiting so they could start their power trowel and went as far as to place the machine on the concrete. Unbeknownst to me, as I am a police officer and had to go on duty, at this point they left the job. It was not until late the next morning that I found out my driveway was unfinished with gravel showing in spots. I called them and they told me they were on their way to finish it up. I thought his should have been completed last night but they told they would do it today. They arrived early afternoon and began roughing it with cinder blocks then they sprinkled it with Portland cement and began to power trowel it. They said they do this all the time and it will be just fine because the concrete is still green. Is there anyone that can shed some light on this procedure? It seems to me that the surface will not last due to poor adhesion. Thanks all, when I saw my drive I was the one that was GREEN. Gary





RE: Finishing concrete after an overnight cure
The concrete must be finished while it is still in a plastic state. They are proposing to finish with a skim coat of neat cement paste which will crack and likely debond/scale.
Poor practice and not acceptable in any industry standard.
RE: Finishing concrete after an overnight cure
RE: Finishing concrete after an overnight cure
RE: Finishing concrete after an overnight cure
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Finishing concrete after an overnight cure
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Finishing concrete after an overnight cure
Rule of thumb is that you must start the power trowel process when stepping on the concrete leaves a 1/8" boot print. They waited far beyond that. They let the bleed water and "watery cement" at the top cure, which will deteriorate and leave a weak layer of concrete that will dust over time.