Solid Rubber tyres - reasonable load ?

[corrosionman]

We are struggling to find the best material for some solid tyres which carry the outer end of a beam which rotates over a large water treatment tank Speed is very slow and the tyre runs on a smoothe concrete surface.
- Our steel wheels are 20" diameter with a flat rim 5" wide and the tyre is 1" thick. Each tyre carries approx 5 tons load. Urethane tyres eventually split and separate from the steel. Rubber behaves much the same. There are many reports claiming superiority of either product against the the other but I am wondering if possibly our wheels are too heavily loaded Please does anyone knows of any maximum load recommendations or what is the best hardness for the urethane or the rubber ?
Any suggestions much appreciated.
Corrosionman.

 

[GrahamBennett]

Personally, I wouldn't specify polyurethane for this application. I would prefer to use a 100phr natural rubber-based earthmover type tyre tread compound that has high tear resistance and relatively high resilience (low temperature build up). I suggest you speak to a local tyre retreading company to see what they have available.