Contents of this article
What is the frost resistance level of concrete?
What are the levels of frost resistance?
Freeze-resistant concrete standards?
How to explain the frost resistance of concrete?
What are the standards for concrete frost resistance testing?
What is the highest frost resistance grade of frost-resistant concrete? Where can I find it?
What is the difference between antifreeze level and antifreeze level?
Concrete with a frost resistance level above what level is called frost-resistant concrete?
Concrete with a frost resistance grade ≥F50 is called frost-resistant concrete
The frost resistance of concrete is expressed by the frost resistance grade, which is divided into F50, F100, F150, F200, F250, F300, There are nine grades in total: F350, F400 and F400. Concrete with a frost resistance grade of F50 or above is referred to as frost-resistant concrete.
In the existing online literature, there may be two expression methods: D and F. Among them, the following construction projects are distinguished: The frost resistance of concrete is expressed by the frost resistance grade, which is based on the repeated freezing and thawing that the concrete specimen can withstand. The number of cycles (slow freezing method), the frost resistance of concrete is divided into 9 levels: D50, D100, D150, D200, D250, D300, D350, D400 and >D400 (according to "Concrete Quality Control Standard GB50164-92") Water conservancy construction project: The frost resistance grade of concrete is divided into 7 grades: F400, F300, F250, F200, F150, F100, and F50 (according to the "Hydraulic Concrete Structure Design Specification SL191-2008").
What are the frost resistance levels?
1.
GBJ50164-92 divides concrete into the following frost resistance grades: F10, F15, F25, F50, F100, F150, F200, F250, F300 and other nine grades. Indicates that the concrete can withstand repeated freeze-thaw cycles of 10, 15, 25, 50, 100, 150, 200, 250 and 300 times respectively.
2.
Concrete with a frost resistance grade ≥F50 is called frost-resistant concrete. The anti-permeability grade is determined based on the maximum water pressure that a 28-day-old standard specimen can withstand when tested according to the standard test method. GB 50164 "Concrete Quality Control Standard" is based on what the concrete specimen can withstand during the anti-permeability test. The maximum water pressure of concrete is divided into five levels: P4, P6, P8, P10, and P12, which correspond to resistance to 0.4, 0.6, 0.8, 1.0, and
Anti-freeze concrete standard?
The frost resistance of concrete is expressed by the frost resistance grade. According to the number of repeated freeze-thaw cycles (slow freezing method) that the concrete specimen can withstand, the frost resistance of concrete is divided into D50, D100, D150, and D200. , D250, D300, D350, D400 and >D400, a total of 9 grades (according to "Concrete Quality Control Standard GB 50164-92")
How to explain the frost resistance of concrete?
The frost resistance of concrete refers to the ability of concrete to maintain strength and appearance integrity after being subjected to multiple freeze-thaw cycles in a water-saturated state. The frost resistance of concrete is expressed by a frost resistance grade (formerly a designation). The anti-freeze level is the maximum freezing level that a 28-day-old test block can withstand repeated freezing and thawing cycles using the slow freezing method after being saturated with water, so that the compressive strength does not decrease by more than 25% and the mass loss does not exceed 5%. Determined by the number of melting cycles. The frost resistance grades of concrete are divided into nine categories: F
10, F1
5, F2
5, F50, F100, F150, F200, F250 and F300. Grades, respectively indicating that the number of times concrete can withstand repeated freeze-thaw cycles are
10, 1
5, 2
5, 50, 100, 150, 200 , 250 and 300.
What are the standards for concrete frost resistance testing?
Frost resistance of concrete:
Refers to the ability of concrete to resist freeze-thaw cycles without damage when it contains water.
The reason for the freeze-thaw damage of concrete is that the volume of water in the concrete expands after freezing. When the expansion force exceeds its tensile strength, fine cracks will occur in the concrete. Repeated freezing and thawing cracks will continue to expand, causing the concrete to collapse. Strength decreases until failure.
1. The key to improving the frost resistance of concrete: increasing the density. The measures are to reduce the water-cement ratio, add air-entraining agent or water-reducing air-entraining agent, etc.
2. Representation method: Expressed by the anti-freeze mark. The anti-freeze mark is based on the compressive strength of the 28-day-old stone after repeated freeze-thaw cycles at -15~200C after being saturated with water. It is expressed by the maximum number of freeze-thaw cycles it can withstand when the weight loss does not exceed 25% and the weight loss does not exceed 5%. Concrete is divided into the following nine frost resistance grades: D10, D15, D25, D50, D100, D150, D200, D250, and D300, which respectively indicate that the concrete can withstand repeated thawing cycles of not less than 10, 15, 25, 50, 100, and 150 , 200, 250 and 300 times.
The above is the slow freezing method to determine the frost resistance. For concrete with high frost resistance requirements, the quick freezing method can also be used, that is, the relative elastic modulus value is not less than 60% and the weight loss rate is not less than 60%. The maximum number of cycles when it exceeds 5% is used to express its frost resistance index.
What is the highest frost resistance grade of frost-resistant concrete? Where can I find it?
The highest frost resistance grade of frost-resistant concrete is: F400. The standards can be found in the Construction Engineering "Test Methods for Long-term Performance and Durability of Ordinary Concrete" (GBJ82-85) and "Design Specifications for Hydraulic Concrete Structures SL191-2008".
The frost resistance grade of concrete is achieved when a test block aged 28 days is subjected to repeated freeze-thaw cycles after being saturated with water, so that the compressive strength does not decrease by more than 25% and the mass loss does not exceed 5%. Determined by the maximum number of freeze-thaw cycles it can withstand. GBJ50164-92 divides concrete into the following frost resistance grades: F10, F15, F25, F50, F100, F150, FThere are nine grades, including 200, F250, and F300, which respectively indicate that the concrete can withstand repeated freeze-thaw cycles of 10, 15, 25, 50, 100, 150, 200, 250, and 300 times. Water conservancy construction project: The frost resistance grade of concrete is divided into 7 grades: F400, F300, F250, F200, F150, F100 and F50.
Concrete with a frost resistance grade ≥F50 is called frost-resistant concrete.
What is the difference between antifreeze level and antifreeze level?
The frost resistance grade of concrete is the test block that is 28 days old and is subjected to repeated freeze-thaw cycles after being saturated with water, so that the compressive strength does not decrease by more than 25%, and the mass loss does not exceed 5%. determined by the maximum number of freeze-thaw cycles it can withstand.
Concrete anti-freeze refers to concrete constructed in winter. After technical measures are taken to prevent concrete pouring, it meets the technical requirements without frost heaving damage before reaching the critical strength of freezing. It should be called anti-freeze concrete. </p
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