Table of Contents
What is single size coarse aggregate?
A coarse aggregate which has the sizes of particles mainly belonging to a single sieve size is known as single size aggregate. For example 20 mm single size aggregate mean an aggregate most of which passes 20 mm IS sieve and its major portion is retained on 10 mm IS sieve.
What is meant by graded aggregate?
Graded aggregate means using different size of aggregates so as to have a uniform consistency in concrete. Different sizes of aggregate will fill the gap and achieve higher strength. If this property is achieved then your concrete is said to be plastic and it can be used for actual application.
What is coarse graded aggregate?
Coarse aggregate can be described as uncrushed, crushed, or partially crushed gravel or stone. This type of aggregate is described as how it is graded. For example, ¾” nominal size graded aggregate means that most of the aggregate passes a 3/4” sieve.
What is uniformly graded aggregate?
Uniformly Graded – Also known as narrow gradation, a uniform gradation is a sample that has aggregate of approximately the same size. The curve on the gradation graph is very steep, and occupies a small range of the aggregate. It refers to a gradation that contains most of the particles in a very narrow size range.
What is open graded aggregate?
An open graded cold mix is a coarse aggregate mix (very small amount of fine aggregate) with a large amount of air voids to allow for water to drain. These mixes can be used as a base or surface course and show excellent resistance to fatigue, reflection cracking, rutting, and shoving.
What is grading of aggregate and its significance?
Grading of aggregates is determining the average grain size of the aggregates before they are used in construction. This is applied to both coarse and fine aggregates. Similarly, in fine aggregates also, voids are left that have to be filled with still finer particles (of cement).
What are the different grades of aggregate?
Grading Limits for Fine Aggregates
| IS Sieve Designation | Percentage Passing | |
|---|---|---|
| 4.75 mm | 90 – 100 | 95 – 100 |
| 2.36 mm | 60 – 95 | 95 – 100 |
| 1.18 mm | 30 – 70 | 90 – 100 |
| 600 microns | 15 – 34 | 80 – 100 |
What does aggregate size mean?
‘Aggregate’ is a term for any particulate material. – Coarse aggregates are particulates that are greater than 4.75mm. The usual range employed is between 9.5mm and 37.5mm in diameter. – Fine aggregates are usually sand or crushed stone that are less than 9.55mm in diameter.
What size is #57 aggregate?
1 to 0.19 inch
A #57 aggregate (combining the gradation of #5 and #7 aggregates) ranges from 1 to 0.19 inch (No. 4 sieve—25 to 4.75 mm) and has the following gradation (amounts finer than the given sieve size): 1½-inch sieve—100\% passing; 1-inch—95 to 100\%; ½-inch—25 to 60\%; No.
What is grading and why is it important that aggregates are properly graded?
The grading or size distribution of aggregate is an important characteristic because it determines the paste requirement for workable concrete. The more these voids are filled, the less workable the concrete becomes, therefore, a compromise between workability and economy is necessary.
What open grade means?
An aggregate containing little or no mineral filler, or in which the void spaces in the compacted aggregate are relatively large.