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How come I cant order concrete and pump today? 1

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COEngineeer

Structural
Sep 30, 2006
1,186
Picture I got from someone. It is Bayside condo foundation concrete pour in San Diego of the south one-half only of the ten-foot-thick RAFT slab, which supports the 35 story tower. This was a 258 truck-ballet in which the contractor placed 11,500 yards of concrete in one monolithic pour that got started at five in the morning and finished by three in the afternoon." 258 trucks in 10 hours = 26 trucks per hour = 1 truck every 2 minutes 20 seconds.

san_diego_concrete_pour.jpg


Sea Water Intake and Jetty Construction
 
The red, yellow, blue, and white of the trucks and pumps look nicely coordinated.
 
Great photo.

But 11,500 yards in 258 trucks?
 
Agree... excellent photo.

Also agree about the number of trucks... I thought a typical truck carried about 10 cu. yds? Am I mistaken?
 
I think 258 trucks going back and forward all day.

Sea Water Intake and Jetty Construction
 
I think I count about 39 cement trucks right there in that one shot.

Idle thought...does adding all that weight move that rail line any?
 
JStephen - you mean AFTER they took out 18 feet of soil?

 
I did a very similar project about 10 years ago (8 foot thick mat supporting 30 story tower). In order to minimize traffic disruption, the city made the contractor start the pour in the evening after rush hour and they poured all through the night to finish before morning rush hour.
 
i spy with my little eye
43 trucks,
16 pumps (maybe 17 or 18 or just extra tube),
1 train
no Waldo

Looks like we could get those cranes up and at it for some bucket-placing.
 
very nice.
 
Hopefully the testing company sent more than one technician.
 
I wonder how they handled temperature and shrinkage and what proportions and admixtures they used.
 
I would suspect that much of the concrete tech work was done at the different plants producing the concrete to make adjustments faster. I always enjoyed being a tech on the big jobs because you started about 3 or 4 hours before the start of the pour and got a week's work in 2 or 3 days.

It must have taken a number of plants and renting trucks from the competitive concrete suppliers. The main supplier cannot shut down other jobs just because of one job, so rentals are usually necessary. There were not too many spare pumpers, so that could have been a critcal equipment factor in addition to access.

Usually, you start pouring slow and ramp up the number of trucks as you go to maintain an even flow of concrete and minimize the waiting time. You cannot afford to overload the site early because you end up with a build-up of waiting time that you cannot dig out of. Each truck used hauled an average of only 44 yards, but I imagine some trucks got up to 60-70 or more yards if they hauled from a nearby plant.

Waldo was in the white truck in crosswalk.
 
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