delay in concrete trucks
delay in concrete trucks
(OP)
Hello,
While casting a retaining wall and because of the heavy traffic, a delay of 2.5 hours between the concrete trucks was noticed.
When the concrete arrived at the site, the slump was taken and found to be 16 cm (a super plasticizer was used - no water has been added to the mix during the travel since one of our workers was next to the driver). Therefore, the engineer agreed to cast the concrete.
Regarding the concrete which has already been casted and located in the formwork, should I worry about any cold joint formation ? the concrete initial setting time is set to 2 to 3 hours.
I have verified the wall reinforcement and found that it was enough to cater for the shear friction through the entire area of the retaining wall.
Any remarks regarding the above or things should I do in case this situation happens again ?
thank you
While casting a retaining wall and because of the heavy traffic, a delay of 2.5 hours between the concrete trucks was noticed.
When the concrete arrived at the site, the slump was taken and found to be 16 cm (a super plasticizer was used - no water has been added to the mix during the travel since one of our workers was next to the driver). Therefore, the engineer agreed to cast the concrete.
Regarding the concrete which has already been casted and located in the formwork, should I worry about any cold joint formation ? the concrete initial setting time is set to 2 to 3 hours.
I have verified the wall reinforcement and found that it was enough to cater for the shear friction through the entire area of the retaining wall.
Any remarks regarding the above or things should I do in case this situation happens again ?
thank you






RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
For this reason, the slump was taken. If the slump was too low, it would have meant that the concrete has began to harden. Therefore, it will be rejected. Otherwise, if the slump is still ok, the concrete could be used.
RE: delay in concrete trucks
I had your situation many times and finally carried a copy of the specs describing contract concrete requirements and inspection requirements which I gave to the Contractor when this issue arose. As an inspector, I never had authority to direct construction except in an emergency situation. But the concrete superintendent would turn them away when he saw me recording the times on the tickets.
RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
RE: delay in concrete trucks
Always take an extra set of cylinders in those situations when it is not clear whether the contract requirements have been violated. The special inspectors can't stop a contractor from working, you can only inform them that their material or workmanship violates the contract documents. In fact it is very risky telling them to stop, because if they do and you are wrong, they will come after your company. As others can surely relate to, I have told contractors hundreds of times that their work is not meeting the contract - they continue anyways. Document, document, document!!! and get in touch with the EOR ASAP.
"It is imperative Cunth doesn't get his hands on those codes."
RE: delay in concrete trucks
In case of a cold joint formation and as a I have indicated in my first post, the existing reinforcement is verifying the shear friction through the entire area. Should I have any other worries ?
6 cubes were taken from each delayed concrete truck. therefore, I can and will assess if any decrease in the specified strength of the concrete is noted and will act correspondingly.
RE: delay in concrete trucks
RE: delay in concrete trucks
Water intrusion? Maybe not depending on what this wall is doing.
6 cubes? Why cubes? of just the cement matrix?
"It is imperative Cunth doesn't get his hands on those codes."
RE: delay in concrete trucks
"It is imperative Cunth doesn't get his hands on those codes."
RE: delay in concrete trucks
The OP is in the country "AO" (Angola?) and they probably use cubes not cylinders for compression testing, likely to British standards.
RE: delay in concrete trucks
Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries
www.americanconcrete.com
RE: delay in concrete trucks
Thank you all for your input.
RE: delay in concrete trucks
"I'm not telling you to stop, I'm telling you it's wrong"...