ASTM C672
Full Name
ASTM C672 – Standard Test Method for Scaling Resistance of Concrete Surfaces Exposed to Deicing Chemicals
Scope
ASTM C672 simulates accelerated winter conditions in a controlled laboratory environment. The testing process requires precision in both specimen preparation and environmental cycling.
1. Specimen Preparation and Curing
Concrete specimens are cast and finished according to standard practices. Because curing history significantly impacts a concrete surface’s scaling resistance, the standard dictates a strict curing regimen. Typically, specimens undergo 14 days of moist curing followed by 14 days of air drying in a controlled environment.
2. Ponding the Surface
Once cured, a watertight dike or dam is constructed around the perimeter of the specimen’s top surface. The contained area is then covered with a specified deicing solution. The standard default is a calcium chloride solution, though other deicers can be used if specified by the client or project requirements.
3. Freeze-Thaw Cycling
The ponded specimens are placed in a freezing environment. A single cycle consists of 16 to 18 hours in a freezing environment, followed by 6 to 8 hours in a thawing environment at room temperature. A standard test requires 50 complete freeze-thaw cycles.
4. Visual Evaluation
Every five cycles, the specimens are flushed clean, visually examined, and evaluated for surface scaling before the deicing solution is reapplied.
The core output of ASTM C672 is a qualitative visual rating assigned to the concrete surface at the conclusion of the test. Evaluators use a standardized scale from 0 to 5 to grade the severity of the damage:
- Rating 0: No scaling.
- Rating 1: Very slight scaling (maximum 1/8 inch depth, no coarse aggregate visible).
- Rating 2: Slight to moderate scaling.
- Rating 3: Moderate scaling (some coarse aggregate visible).
- Rating 4: Moderate to severe scaling.
- Rating 5: Severe scaling (coarse aggregate visible over the entire surface).
By tracking these ratings over the 50 cycles, technicians can plot the degradation rate and determine if the concrete meets the necessary performance criteria for its intended environment.
ASTM C672 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM C672 standard.
We offer comprehensive ASTM C672 testing services to help ready-mix producers, contractors, and admixture manufacturers validate their products with confidence. Contact us for more information.
Resources
Keywords
resistance-scaling; deicing chemicals; freezing and thawing; visual examination; calcium chloride; resistance-frost; concrete-weathering tests; visual rating; protective coatings; air-entrained; moist storage; air storage; curing compounds; water-cement ratio; slump