What is ASTM D570?
What is ASTM D570?
ASTM D570—Water absorption of plastics—describes various procedures that evaluate the amount of water that is absorbed by the sample. Moreover, it also permits to assess the uniformity of the imbibed specimen.
Why determination of water absorption is important?
Water absorption is used to determine the amount of water absorbed under specified conditions. Factors affecting water absorption include: type of plastic, additives used, temperature and length of exposure. The data sheds light on the performance of the materials in water or humid environments.
How do you test water absorbency?
Water absorption tests: The Cobb test determines the amount of water absorbed into the surface by a sized (non-bibulous) paper, paperboard, and corrugated fibreboard paper or paperboard sample in a set period of time, usually 60 or 180 seconds (Cobb60 or Cobb180). Water absorbency is quoted in g/m2.
How is water absorption capacity calculated?
It is calculated as the moisture content, which is equal to: (weight of the container with wet soil minus the weight of the container with dry soil) divided by (weight of the container with dry soil minus the weight of the container), then multiplied by 100 to express it as a percentage.
How do you test water for brick absorption?
The Procedure of Water Absorption Test of Bricks
- Take any five random bricks from a lot of brick as a specimen.
- Dry the specimen in a ventilated oven at a temperature of 105°C to 115°C till it achieves considerably constant mass.
- Cool the specimen to room temperature and take its weight (M1).
Why is water absorption of bricks important?
Apart from compressive strength, water absorption is an important property in masonry. This property can affect the quality of the brick itself and the bond strength between the brick and mortar in masonry structures and can result in reducing its strength properties.
What is the maximum limit of water absorption of aggregate?
3% maximum
Regarding aggregate absorption it says “Water absorption of aggregates is retained at 3% maximum.
Why is water absorption testing of aggregate important?
What is Aggregate Water Absorption Test? Water absorption gives an idea of strength of aggregate. Aggregates having more water absorption are more porous in nature and are generally considered unsuitable unless they are found to be acceptable based on strength, impact and hardness tests.
How do you calculate absorption capacity?
Formula used is Water absorption = [(A – B)/B] x 100%.
What is Cobb value?
General information. The Cobb value provides information about the water absorption capacity of cartonboard samples. The Cobb test determines the amount of water that is taken up by a defined area of cartonboard through one-sided contact with water, within a certain amount of time.
What are the limits of water absorption of burnt clay bricks?
Water absorption (IS 3495 (2): 1992) of bricks should not be more than 20% by weight up to class 12.5 and 15% for higher classes when bricks are immersed in cold water for 24 hours. Efflorescence (IS 3495 (3): 1992) should not be more than ‘moderate’ for class up to 12.5 and ‘slight’ for higher classes.
What is water absorption capacity of brick?
The acceptable water absorption for clay bricks are between 12% and 20%. If you are using engineering bricks the closer you are to the 12% the better the result will be. When the water absorption is too low, i.e. below 12%, it may be difficult to obtain a proper bond between the mortar and the bricks.
Should be the water absorption percentage of a good brick?
What will happen if a brick absorb more water?
Bricks often absorb water from the fresh mortar when they are laid dry. If the rate of water absorption is high, it may effect the hydration of mortar and result in poor bonding between bricks and mortar.
What is the limitations of water absorption test?
The maritime code BS 6349 specifies that water absorption should not exceed 3%, or 2% in critical conditions such as highly aggressive chloride or freeze–thaw exposure, when tested in accordance with BS 812-2. The drying shrinkage test in BS 812 Part 120 is limited to aggregates with water absorption <3.5%.
What is the maximum absorption limit for coarse aggregate?
Max water absoption limit for coarse aggregates in any climatic condition should not be more than 2%. And for fine aggregates range varies from 0.3–2.5%. Max permissible limit of fine aggregates is 3%.
What is absorption capacity of aggregate?
Absorption capacity (AC) of an aggregate represents the maximum amount of water the aggregate can absorb. W SSD and W OD represent the weight of the aggregate sample in the SSD and OD states respectively.
What is a reasonable range for absorption of a fine aggregate?
According to BS 8007, aggregates should comply with either BS 882 or BS 1047 and have an absorption, as measured in accordance with BS 812-2, generally not greater than 3%. The Civil Engineering Specification for the water industry (CESWI) follows BS 8007 and water absorption should not exceed 3%.
Why Cobb test is important?
The Cobb test is essential as it tests the ability of the paper to resist the penetration of water and quantity of water absorbed by the surface of fiberboard. If fiberboard absorbs too much water, the box may have difficulty maintaining strength and integrity.
