Pre Stressed Concrete Lintels Composite Vs Non Composite

[self builder 123]

Hi

I understand that pre stressed concrete lintels are available as composite and non composite.

Could anyone please tell me the difference and in which application each would be used ?

Cheers

 

[denso13]

http://www.esi.info/detail.cfm?R=71.21719

Composite are smaller in section for use with brick or blockwork above. Non-composite are larger in section for use with little or no brickwork above.