Cost of Foam Concrete

[molerat2210]

Does anyone know the typical range of costs for foam concrete? I am interested in using as lightwieght fill around and under large water storage tanks to reduce settlement and reduce downdrag on auger cast piles. With this option, it would be 70,156 cubic yards of foam concrete from an onsite batch plant with a unit weight of about 40 pcf. This is either a reasonable option or out of the ballpark depending on the cost. I suspect it's out of the ballpark but I must humor the client.

 

[Ron]

Look at more than the raw cost of the concrete. Perhaps you'll have to design your entire foundation system for a more robust foundation if you don't use it.

I've used the material in large quantities (for structural fill to salvage hollow "rocks" at a major theme park in central Florida). For that application, it was one of only two valid solutions, absent removing the rock structures and re-creating in some other fashion (extremely expensive). It was the better (more structural efficacy) of the two options.

Look at settlement with and without.
Look at downdrag with and without.
Look at construction procedures, with and without.

 

[molerat2210]

Thanks for your post Ron,

Yes, downdrag is a significant and expensive issue. For smaller diameter deep foundations (30 inches or less) with 65 tsf end bearing on rock and side friction in the rock socket, the allowable capacity is completely lost to downdrag. Therefore, I am looking at 1,200 36-inch shafts (cough) at an average of about 60 feet deep. Pre-loading looks to be a great alternative with highly favorable Cv values (1 to 1.5) but client does not want to want to wait the 7 months for settlement due to neighborhood disturbance and consent decree deadline (he will probably change his mind later though once cost reality sets in). Therefore, lightweight fill is at least being considered, for now.

 

[BigH]

Why not contact Leo Legatsky at Elastizell? I used this back in 1983 in British Columbia - worked beautifully. If my grey cells are working right, it cost about 15% more than normal concrete - but who knows now . . .

 

[molerat2210]

Thanks for the tip BiH.