Practical Maximum Load on Elastomeric Bearings

[OSUCivlEng]

I am curious as to what the maximum practical service load is for a steel reinforced elastomeric bearing designed per Method B. A quick search of State DOT design manuals shows some considerable differences. For example Iowa uses 450 kips, Nevada uses 650 kips, South Carolina uses 750 kips and Washington state uses 800 kips. Only South Carolina gave a reason which was "uniform heating and cooling during vulcanization of such a large mass of elastomer becomes difficult, because elastomers are poor heat conductors. Manufacturing constraints thus impose a practical upper limit on the size of most steel-reinforced elastomeric bearing pads".