Short answer
USDA rates soils for risk of corrosion to concrete, driven mainly by sulfate and sodium content, texture, moisture and acidity. Our sampling found Lemoore’s main soils, Grangeville, Lakeside and Lemoore, rated high. Tulare’s Colpien and Visalia’s Akers rate moderate. NRMCA says sulfate-resisting cements and lower permeability are how concrete resists sulfate.
Key facts
- Corrosion of concrete is driven mainly by sulfate and sodium content, texture, moisture and acidity (USDA NRCS California)
- Lemoore: Grangeville, Lakeside and Lemoore soils rated high (USDA soil survey)
- Sulfate-resisting cements include Type II and Type V portland cement (NRMCA CIP 44)
- Sulfate resistance comes from sulfate-resistant cementitious materials and reduced permeability (NRMCA CIP 44)
Ratings by town
Major soils in each city and USDA’s rating for risk of corrosion to concrete:
| Town | Soils rated moderate or high | Soils rated low |
|---|---|---|
| Exeter | None | Flamen, Exeter |
| Visalia | Akers (moderate, 8%) | Tagus, Nord, Grangeville |
| Tulare | Colpien (moderate, 52%) | Nord, Flamen, Yettem |
| Lindsay | None | Exeter, Greenfield |
| Woodlake | None | San Joaquin, San Emigdio, Seville, Porterville |
| Hanford | None | Nord, Wasco |
| Lemoore | Grangeville (high, 38%), Lakeside (high, 14%), Lemoore (high, 14%) | Nord |
What drives the rating
USDA’s California interpretations define risk of corrosion as soil-induced chemical or electrochemical action that weakens uncoated steel or concrete. For concrete, the rate depends mainly on the soil’s sulfate and sodium content, texture, moisture and acidity. USDA adds that installations crossing different soil layers are more exposed than ones within a single layer.
How concrete is made to resist it
NRMCA’s durability guide sets out a sulfate exposure category based on the water-soluble sulfate in the soil or water touching the concrete. Resistance comes from sulfate-resistant cementitious materials, including Type II and Type V portland cements and moderate and high sulfate-resistant blended cements, plus reduced permeability. Supplementary cementitious materials such as fly ash and slag also improve sulfate resistance, according to the same guide.
The rating is for the soil type, not your lot. If you are in a high-rated area, ask what cement and mix the estimate is based on.
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