Table of Contents
What is 20mm down?
Description. Scalpings (20mm Down to Dust) is the name given to a crushed stone aggregate similar in composition to MOT, which is typically used as a medium quality fill or sub-base material.
What is the meaning of 20mm?
20 mm to inches = 0.7874 inches. 30 mm to inches = 1.1811 inches. 40 mm to inches = 1.5748 inches.
How can you tell the quality of 20mm aggregate?
Sieve analysis is done to check the gradation of aggregate. The test is done as follow. Shake vigorously the sieve set for at least 2 minute. Then measure the weight of aggregate on each sieve and express it as the percentage of passing.
Is 20mm half inch?
Smaller items are usually measured in milimeters as it is a more accurate measurement….
| MM | Approximate Size In Inches | Exact Size In Inches |
|---|---|---|
| 18mm | Just short of 3/4 Inch | 0.70866 Inches |
| 19mm | Little under 3/4 Inch | 0.74803 Inches |
| 20mm | Just short of 13/16 Inch | 0.78740 Inches |
| 21mm | Little over 13/16 Inch | 0.82677 Inches |
Why would you use different size aggregates?
Using larger coarse aggregate typically lowers the cost of a concrete mix by reducing cement requirements, the most costly ingredient. Less cement (within reasonable limits for durability) will mean less water if the water-cement (w/c) ratio is kept constant.
Which types of aggregates are good for workability?
Which type of aggregates gives good workability? Explanation: The aggregates which gives more ease of working and workability is round aggregate, flaky and angular also used in some cases, irregular also are used in pavements.
How do you determine aggregate quality?
In order to decide the suitability of the aggregate for use in pavement construction, following tests are carried out:
- Crushing test.
- Abrasion test.
- Impact test.
- Soundness test.
- Shape test.
- Specific gravity and water absorption test.
- Bitumen adhesion test.
What is the difference between 10mm and 20mm aggregate?
Depending on the mix design, either can be used to make essentially any range of concrete strengths. When you use a smaller aggregate, such as the 10mm as your nominal coarse aggregate size, the specific surface area of the total volume of coarse aggregate is much higher than for the 20mm aggregate.
What is the difference between NMSA 20 mm and 40 mm?
In general 20 mm is used as NMSA but use of 40 mm provides economy for substructures. For too congested structures 12.5 mm or 10 mm is also used. For PQC 31.5 mm and DLC 2 When the size of aggregate is greater than 4.75 mm ( say 5 mm) it is called coarse aggregate. Graded aggregates are used for better particle packing.
What is the sieve size for grading aggregates?
Sieve Size for Grading of Aggregates. Coarse Aggregates: 80 mm, 40 mm, 20 mm, 10 mm, IS Nos. 480. Fine Aggregates: IS No. 480, 240, 120, 60, 30 and 15. All in aggregates: 80 mm, 40 mm, 20 mm, 10 mm, Nos: 480, 240, 120, 60, 30 and 15.
What is the grading of aggregates?
Grading of Aggregates. The number of sieves is five for the coarse aggregates and ten for all-in-aggregates. It is only six in the case of fine aggregates. Sieve Size for Grading of Aggregates. Coarse Aggregates: 80 mm, 40 mm, 20 mm, 10 mm, IS Nos. 480 Fine Aggregates: IS No. 480, 240, 120, 60, 30 and 15.