First, the answer to Vol. 14 (last week).
I chose this one because it appeared relatively straightforward, and something being performed correctly! However, Bob Killian makes an excellent observation I missed.
First, the correct:
How many of you see air pressure test gauges like this on your sites? Hopefully all of you who are following ASTM D5820-95 see air pressure test gauges with graduations of 1 PSI! This is a commonly overlooked item on many installations – I’ve seen installers with 2 PSI graduations up to 5 PSI graduations on their test gauges, which clearly do not meet the ASTM requirements. Section 6.5 of ASTM D5820 states, “Pressure Gauge, capable of indicating the air pressure in 7 kPa (1lb/in2) within the test range.”
I featured this topic in a February 2018 blog (quiz) (link: https://uncontained.co/2018/02/07/can-you-pass-this-air-pressure-testing-quiz/ ). Unfortunately, we still see a lot of incorrect gauges being used by installers, and not being caught by CQA!
Now, the suspect:
As Bob pointed out, the white line could have been for the original overlap, and if so, the final overlap probably does not meet specifications. That is something that should be checked at the cut which would have been below the needle. Using overlap lines marked on the geomembrane by the installer is sometimes a good way of monitoring overlap!
In these blog posts, Do You See What Glen Sees, I will present a photograph or short video related to earthwork or geosynthetics construction and have you identify the significance of what you’re seeing.
It could be things being done correctly or incorrectly. Primarily, these will be things that impact quality.
In addition to my blog, I’ll post this content on X and LinkedIn. You can post your response on one of those two.
I’ll give you my thoughts on each photo or video when I post the next installment.
Do you see what I see? Or did you find something I missed? I’m excited to find out!
