Underground lightweight base 1

[Cam83]

Can anyone give me an insight into a suitable material to use as a base for mounting an electrical link box underground. We have previously used a bed of sand and a 600mmx900mm concrete slab however the concrete is to heavy and i am loooking for a lighter alternative. The 600mmx900mm piece of material would need to support around 200kg. I have heard the following materials may be useful;
1)Polymer Concrete.
2)Treated plywood.
Can anyone let me know as to whether these materials are suitable and f so who can supply the material? and also;
Any other suitable materials available?

 

[SlideRuleEra]

Perhaps you could consider flowable fill, a mixture of cement, flyash, and water. Weight is about 2/3 of concrete. Very economical, available, and easy to use. Here is a typical link for general information:

http://www.gcpa.org/flowable_fill.htm