What are the grades of aggregate?

What are the 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 are the types of gradation?

there are two main gradation types categorised by aggregate morphology, namely continuous gradation and gap gradation, or three types by air voids, namely dense gradation, open gra- dation and semi-open gradation.

What is well graded aggregate?

Well graded : Well-graded aggregate has a gradation of particle size that fairly evenly spans the size from the finest to the coarsest. A slice of a core of well-graded aggregate concrete shows a packed field of many different particle sizes. It is characterized by the S- shaped in gradation curve.

What is aggregate grading test?

Test aggregate to determine the quality of material. A gradation test measures the size distribution, or amount of coarse and fine aggregates in a sample. Use a sieve analysis to test gradation. Stack mesh screens, or sieves, in order by size.

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 are the 2 types of aggregates?

Types of aggregates include Coarse aggregate and fine aggregate. The aggregate of each type is further sub-divided into many types and classification based on its size.

What is gap grading of aggregates?

Question: What are gap-graded aggregates and how are they used in concrete construction? Answer: Aggregate is gap-graded when intermediate sizes are essentially absent from the gradation curve. Usual gap-graded mixes contain aggregate retained on a 3/4- or 1 1/4-inch sieve, and particles passing the No. 4 sieve.

What is a well graded aggregate?

What is dense graded aggregate?

Dense graded is a mechanically crushed rock aggregate. The particle size distribution is engineered so that when compacted, the resulting voids between the aggregate particles, expressed as a percentage of the total space occupied by the material, are very small.

What are the size numbers (grading sizes) for coarse aggregates?

The grading of coarse aggregates is done for 13 size numbers (grading sizes), as follows: Size numbers (grading sizes) for coarse aggregate apply to the amounts of aggregate (by weight) in percentages that pass through a set of sieves arranged from top to bottom “in the different size ranges”, as indicated in the above table

How do you grade aggregates?

The grading of aggregate is plotted in a semi-logarithmic graph to get the particle size distribution curve which is in form of ‘S’. Sieve analysis or sedimentation analysis is performed to find out the grading of the aggregates.

What grade of aggregate grade is required for hand-finished concrete?

For hand-finished concrete floors or where a smooth surface texture is desired, fine aggregate with at least 15\% passing the No.50 sieve and 3 \% or more passing the No.100 sieve should be used The coarse aggregate grading requirements of ASTM C 33 permit a wide range in grading and a variety of grading sizes, as shown in Table 7-5

What are the coarse aggregate grading requirements of ASTM C 33?

The coarse aggregate grading requirements of ASTM C 33 permit a wide range in grading and a variety of grading sizes, as shown in Table 7-5 Mixture proportions should be, changed to produce workable concrete if wide variations occur in the coarse-aggregate grading The maximum size of coarse aggregate used in concrete has a bearing on economy.