Usually, you want to order the truck a day or two in advance. Larger town and cities probably have Saturday Service except in off-season in the cold north.
For bollards, you may want to use a higher PSI like 3500 or greater. You’ll want some aggregate in the mix.
It is advisable to do “full air” (air entrainment) if you are finishing the concrete at grade level as opposed to topping it with asphalt or dirt. The primary purpose of air entrainment is to increase the durability of the hardened concrete, especially in climates subject to freeze-thaw; the secondary purpose is to increase workability of the concrete while in a plastic state in concrete.
You’ll want a slump of about 4″. With slump, the higher the number, the wetter the concrete. You can also order a 3″ slump and have them add water if it seems to dry, but you can’t take water out obviously. Some ready-mix companies are more arbitrary, and the concrete shows up much wetter than expected. If that happens, you can let it sit for 30 mins to an hour before doing final finishing.
You can use some accelerator if it’s cold out – 1% to 2% max for chloride.
Ask your ready-mix concrete company what they suggest if you are unsure.
If you are working over existing asphalt or concrete, you probably don’t want concrete splattered around. Some of it is unavoidable. At least right around bollards, it’s nice to have something on the ground like Ram Board, plywood, masonite, cardboard or tarps. Generally, you can resuse this stuff down the line or on the next job, but you don’t want to blow too much money here.
Also, be careful if there are cars parked close by. Especially when filling bollard pipe, the concrete can really splash up high in the air sometimes.
The truck operator will back up to a bollard and get the chute on and start pouring the concrete. Start with the foundation, and do the pipe only after you have at least half the hole filled. Make sure to go slow at first filling the foundation hole because the concrete can shift the bottom of the pipe and it will be virtually impossible to shift back. While it’s filling, you can distribute concrete around the pipe with a shovel or 2×4.
It helps to use a funnel and a big scoop, like a feed scoop. A funnel is easily made from a traffic cone by cutting off the top. Have the operator fill a wheelbarrow about 1/2 way to work out of. Alternatively, if you aren’t worried about mess, have the chute pour straight into the top of the pipe. You just have to wipe down the pipe then.
Vibrating concrete is always a good idea as it makes it stronger and reduces voids, especially on the surface. It will help concrete fill out inside the pipe too. Even so, it isn’t typically done in bollard installation, but may be specified by engineers or project managers.
The simplest way is to just wear some gloves and form the dome by hand. If you want to get fancy, you can cut an old basketball in half and use that to form the dome. If it’s too wet, just wait.
Be sure you’ve got the dome pretty much under control so you don’t screw up your finishing work below at grade.
Begin floating the concrete at the grade level and add or remove some as needed. Get it floated out nice and smooth. If specified or desired, you can slope the concrete a bit so it’s higher at the pipe and encourages water run-off. Now use an edger to put a nice consistent rounded finish edge around the square. After floating and edging, let it sit for 15 minutes or so, then brush it to give it a nice even texture. Go around the pipe first, then pick a direction and try to make the brushing straight.
Wipe down bollards with rags to remove concrete splatters and drips. Don’t worry about the thin layer of concrete film at this time.
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