Canucks1010
Structural
- Sep 27, 2016
- 21
Hello.
I have a truck loading slab that is susceptible to frost heave (3'-6" frost depth). One engineer is recommending the following to mitigate potential frost heave, but I have my reservations:
1. Place 2 ft of CLSM (flowable concrete fill) below the slab. The intent is this fill acts as a "non-frost susceptible fill" material.
2. Place Ethafoam insulation underneath the CLSM to insulate for frost heave. The insulation extends beyond the slab. The thickness and extend of insulation is optimized considering the CLSM provided some insulating cover.
My reservations are:
1. CLSM cannot be considered a substitute for soil insulating properties. The R-value of CLSM can be as low as 0.1/inch, compared with 0.25/inch for soils. This increase in thermal conductivity should be considered, no? It can extend the assumed frost depth.
2. Ethafoam was selected due to potential for hydrocarbon spills. However, I don't believe Ethafoam is rigid, rather is compressible - therefore, it should not be used for truck loading. A rigid product like Styrofoam HiLoad 60 would be much better - but it is susceptible to degradation due to possible hydrocarbon attack. Any comment?
Perhaps using a concrete insulating material like Cematrix would be more appropriate?
Thank you for the input!
I have a truck loading slab that is susceptible to frost heave (3'-6" frost depth). One engineer is recommending the following to mitigate potential frost heave, but I have my reservations:
1. Place 2 ft of CLSM (flowable concrete fill) below the slab. The intent is this fill acts as a "non-frost susceptible fill" material.
2. Place Ethafoam insulation underneath the CLSM to insulate for frost heave. The insulation extends beyond the slab. The thickness and extend of insulation is optimized considering the CLSM provided some insulating cover.
My reservations are:
1. CLSM cannot be considered a substitute for soil insulating properties. The R-value of CLSM can be as low as 0.1/inch, compared with 0.25/inch for soils. This increase in thermal conductivity should be considered, no? It can extend the assumed frost depth.
2. Ethafoam was selected due to potential for hydrocarbon spills. However, I don't believe Ethafoam is rigid, rather is compressible - therefore, it should not be used for truck loading. A rigid product like Styrofoam HiLoad 60 would be much better - but it is susceptible to degradation due to possible hydrocarbon attack. Any comment?
Perhaps using a concrete insulating material like Cematrix would be more appropriate?
Thank you for the input!
