Do It Right! Lessons from the field not to be repeated
Pouring concrete
- Make sure that the pump hose or a trimmer can get to within 4 feet of the bottom of the pour—remember, they can only drop concrete a maximum of 4 feet!
- Make sure that the concrete gets adequately vibrated (especially if you have lots of reinforcement or conduits) or you may end up with a few oversize “bug holes”.
- Looks like we’re going to get some Extra Special Texture for Free!
- I’m not sure why they put the chair in
backwards...
- The blue line is where the top of the pour is supposed to be. How will we ever get our two inches of cover?
- If the Contractor elects to form the top of a pour, make sure to cut holes in it so you can insure the forms are full.
- Make sure that the concrete gets vibrated adequately when you have large reinforcement, lots of reinforcement or conduits in the pour.
- The contractor formed the top of the end diaphragm here. And didn’t realize the concrete didn’t fill in all the voids until the forms were stripped.
- Best to leave a “window” in the top form, so you can make sure it’s consolidated and full.
- Make sure that the back of semi‐integral abutment of adjacent pours match on top, as the 1” polystyrene under the end diaphragms can only forgive small sins!
- Make sure to check the delivery tickets, and call the plant if you see the mix start to segregate like this. Either they forgot to put the sand in this load, or it is a real wet load being over‐vibrated.
- Inadequate vibration was used when pouring the end diaphragm. Voids that need to be chipped out and repaired on both the top and bottom of this end diaphragm for a semi-integral abutment.
- Remember, don’t pour concrete in areas where vibration is present.
- I recommend the piling operation below be suspended within an hour of the start of the pour if the forms are vibrating.
- If the Contractor elects to form a pour like this, make sure view ports are cut in the forms to make sure the forms are filled and the concrete is adequately vibrated.
- I’m not sure if the railroads will allow pumping concrete over a train anymore!
- When pouring sidewalks or medians on top of finished bridge deck, use lots of sandbags to support the forms.
- We don’t allow holes in the surface of the deck.
- Make sure that the end diaphragms are adequately vibrated. There are times when these are relatively deep and narrow, so the bottom never gets hit with the vibrator, resulting in porous concrete.
- Our curing spec calls for both wet burlap and 6 mil poly. Lots of times, a large footing pour isn’t completed until after “normal” working hours.
- Make sure to hang around until the pour has been put to bed properly!
- The burlap keep the concrete wet, and the poly keeps the burlap from drying out.