Slab on grade edge load

[CTW]

At what distance from the edge of a slab does the load need to be considered an "edge load"? I've got a narrow pavement with fairly channelized wheel loads. All of the references I have on slab/pavement design talk about edge loading but don't specify the distance from the edge where edge loading needs to be considered.

 

[pba]

I work in the UK here 500mm (approx 20 inches) between the point of application and the slab edge defines an internal load. The design process is empirical so there is not a firm dimension.

I'm assuming that your design approach is broadly based on Westergaard...

 

[CTW]

My design approach is based on Westergaard. How is that distance calculated?

 

[cap4000]

I think its based on concrete shear stresses for 3 areas and not a distance. Corner,Edge and Interior conditions. Concrete Flexural Strength = Modulus of Rupture value. Shear Stress max.= 0.27MOR. Its like punching shear stresses from a column to a footing. Check with the PCA Slab publications. Good Luck

 

[el7azeen]

i have aproblem in my projectmthe thickness of the replacement soil under S.O.G less than 5 cm over the reinforced concrete m the designer ignored that thickness in his design of the slab& thickness of the concrete slab on grade 15 cm and # 12 mm at the middle of the slab, i eant toget teh clause of the codes ACI and ASTM about the minimum thicknes under the slab on grade

 

[el7azeen]

i have aproblem in my project the thickness of the replacement soil under S.O.G less than 5 cm over the reinforced concrete footing & the designer ignored the minimum required thickness in his design of the slab on grade & thickness of the concrete slab on grade 15 cm and # 12 mm at the middle of the slab, i want to get the clauses of the codes ACI and ASTM concerning the minimum thicknes under the slab on grade