placing cardboard boxes into cast-in-place concrete 3

[gokhansahin]

dear friends,

i need help on placing cardboard boxes (or rulos) in cast in situ concrete to decrease the weight of the structure. we are planning to use it in slabs or foundations. any help and documentation is welcome. both from design and construction point of views...

regards,
gokhan sahin

 

[oldhand]

This technique has been used in bridge engineering under the term void formers. Tubular polystyrene void formers gained popularity over cardboard tubes. You will find details on spacing and cover requirements in many bridge deck publications. One of the many things you have to consider apart from collapse of the cardboard box, should you go down this route, is flotation of the void former during construction. The tubular former gives better flow and compaction beneath it for the concrete thereby reducing the possibility of inadvertant voids.

 

[SlideRuleEra]

Probably the most notable company to produce these products is Sonoco, who has made these items for over 50 years. Here is a link to that portion of their website, should have plenty of information for you:

http://www.sonoco.com/topnav/produc.../engineered+carriers/building+products+na.htm