Yesterday Mom had to drive all the way to the job site in Massachusetts (and back) in order to help with the first heavyweight concrete pour. The bridge is coming along nicely, with 1/2 of one bascule leaf set in place, and the other half sitting on a barge ready to be installed (see the photo below). There are also two heel girders on-site, waiting to be put in place to start the second bascule leaf.
The pour started at 8:00 sharp when the first concrete truck showed up on site. Unlike a typical concrete pour, the trucks were loaded with only water and cement but no coarse or fine aggregate (rock). This is because the heavyweight aggregate would cause the trucks to be too heavy to drive on the city streets.
Instead, the heavyweight aggregate was added on-site. A small crane was used to pick up the bags of rock and load them into this hopper, where a giant spike was waiting to rip them open. It worked great!
This guy's job was to make sure all the rock got into the hopper, and none spilled out the sides.
Then the mixer truck backed under the hopper and all the rock was dumped in, which resulted in a concrete mix of 5 cubic yards per truck (about 35,000 lb of material).
After mixing, the concrete was tested for air content, slump, and unit weight. Since this was the first pour, there were a lot of spectators from Mass Highway (the bridge owner) observing the tests. Everything looked good, so it was off to the pour site!
Each truck had to back carefully up a 1/4-mile long ramp and then discharge the concrete into the counterweight through this long chute. For a big pour like this, there were about ten workers needed at the counterweight--they lined up the truck, operated the chute, controlled the speed of the concrete coming out, and climbed down inside the counterweight to make sure the concrete got into every nook and cranny.
Mom's job through all of this was to monitor the unit weight of each truck, make sure there were no problems with the falsework (the hangers supporting everything), and show the crew exactly where the concrete needed to go inside the counterweight box.
There were 11 trucks, and the pour took about 5 hours. During breaks between trucks, Mom and her boss took the opportunity to climb around on the leaf and check some survey marks.
The drop to the water here is about 80 feet. It's a good thing Mom is not afraid of heights!
Finally the pour was completed and the concrete crew got to clean up and call it a day. Mom still had work to do though: She and her boss had to weigh the entire bridge by jacking it up with hydraulic rams and reading the pressure. This operation took about 2 hours.
By 5:00 Mom was ready to call it a day and start the 4-hour drive home!
The pour started at 8:00 sharp when the first concrete truck showed up on site. Unlike a typical concrete pour, the trucks were loaded with only water and cement but no coarse or fine aggregate (rock). This is because the heavyweight aggregate would cause the trucks to be too heavy to drive on the city streets.
This guy's job was to make sure all the rock got into the hopper, and none spilled out the sides.
After mixing, the concrete was tested for air content, slump, and unit weight. Since this was the first pour, there were a lot of spectators from Mass Highway (the bridge owner) observing the tests. Everything looked good, so it was off to the pour site!
Each truck had to back carefully up a 1/4-mile long ramp and then discharge the concrete into the counterweight through this long chute. For a big pour like this, there were about ten workers needed at the counterweight--they lined up the truck, operated the chute, controlled the speed of the concrete coming out, and climbed down inside the counterweight to make sure the concrete got into every nook and cranny.
Mom's job through all of this was to monitor the unit weight of each truck, make sure there were no problems with the falsework (the hangers supporting everything), and show the crew exactly where the concrete needed to go inside the counterweight box.
There were 11 trucks, and the pour took about 5 hours. During breaks between trucks, Mom and her boss took the opportunity to climb around on the leaf and check some survey marks.
The drop to the water here is about 80 feet. It's a good thing Mom is not afraid of heights!
Finally the pour was completed and the concrete crew got to clean up and call it a day. Mom still had work to do though: She and her boss had to weigh the entire bridge by jacking it up with hydraulic rams and reading the pressure. This operation took about 2 hours.
By 5:00 Mom was ready to call it a day and start the 4-hour drive home!
Good job Brenda... you go girl!
ReplyDeletewow- that is very very cool.
ReplyDelete-amy