This was a job where an existing slab on city property was right in front of a roll up door. The cities sidewalk was crumbling fast and the new tenant need fresh concrete installed before they moved in the following week.
Since this job was on the sidewalk we had to do the demo and pour in a single day.
Using a gas-powered concrete saw cut the existing concrete about 3″ below the surface so that our concrete would break away in straight clean lines. Because no one was in the building we brought our own power. Using a 5500 generator we powered the large jack hammer to break up the concrete.
We also used the smaller 7″ grinder and the smaller chipping hammer to do some detail work around parts of the building that are staying.
Because of he schedule we didn’t have a dumpster dropped off. We ordered a small 4 yard dumpster and had it arrive about 3 hours after we started. We loaded it while the driver waited and this way we had our demo 100% complete by 11 am. Here is a pic of the opening right before the dumpster showed up. Notice how we chipped the concrete around the bollards down at an angle to preserve the existing footing but allowing for a new finish. Also notice the straight lines at the right of the concrete opening and the sides. However the lines at the bottom had some parts chipped away and I didn’t notice till the concrete truck arrived. But we had to pour anyway because of the tight schedule.
Here is the final picture I took. It’s the concrete after it has been screed-ed with a 2 x 4 and wood float. The new concrete has pea gravel as well as 3/4 aggregate. I also increased the depth from 3-4 inches to 5 inches. As usual I did not install metal reinforcement in the city sidewalk.
The concrete was poured around 12:30 and was finished around 3:30. However I waited until 6:30 before leaving because I wanted to avoid using cones and caution tape to stop accidental foot traffic. Cones and caution tape tend to attract the neighborhood artists and vandals.
Instead I waited till the concrete firm enough to tape down a hardboard panel which is a super thin 3/16 panel that is almost a cross between wood and cardboard. It’s so thin that it’s not a trip hazard and when the concrete has firmed up after a few hours the panel will allow people to walk across it without drawing any attention from people. Since its taped down to the floor it’s also a great deterrent even if someone does notice the fresh concrete.
Sorry but I didn’t get pictures of the panels or the finished product because I was super late getting home for dinner!