What do you mean by well graded aggregate?
Summary. Aggregate Grading – is a measure of how well distributed the sizes of the particles in an aggregate are. A well graded aggregate will have a good range of particle sizes and will have a fair representation from every size of particle.
Why well graded aggregate is most suitable for concreting purpose?
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 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 the requirements of grading of aggregate?
General requirements for fine aggregate include (i) fine aggregate passing the 2.00 mm (No. 10) sieve shall consist of natural or crushed sand, and fine mineral particles passing the 75 μm sieve; (ii) the fraction passing the 75 μm sieve shall not be greater than two-thirds of the fraction passing the 0.425 mm (No.
Why well graded sand is preferred in the construction works?
Well Graded Aggregates in Construction It will help the concrete mix to acquire minimum voids and will require the lesser amount of cement in order to fill up the voids. Well, graded aggregates increase the particle surface area. This is most preferred aggregates in construction.
How does aggregate size affect concrete?
The tensile strength of the concrete is severely affected by increasing the size of the aggregate. On increasing the maximum grain size to 120–180 mm, the reduction in tensile strength is 30–50% as compared with concretes with maximum aggregate size 20 mm. There is also a reduction in the elongation limit.
What is meant by good grading?
—Good grading implies, sample of aggregates containing all standard fractions of aggregate in required proportion such that the sample contains minimum voids. —Well graded aggregate containing minimum voids will require minimum paste to fill up the voids in the aggregate.
What is poor graded aggregates?
• Poor graded : Poor-graded aggregate is characterized by small variation in size . It contains aggregate particles that are almost of the same size. This means that the particles pack together, leaving relatively large voids in the concrete. It is also called “uniform-graded”.
What do you understand by grading of an aggregate?
The grading is the particle-size distribution of an aggregate.
What nominal maximum sizes of aggregate are recommended?
Nominal maximum aggregate size is the largest sieve that retains 10% or more of the total aggregate mixture. 2. Nominal maximum aggregate size is the largest sieve that retains 10% or more of the total aggregate mixture. Sample sizes should not be more that 400 g (14 oz.) greater than the minimum recommended sample mass.
What is grading of aggregates and grading limits?
Grading refers to the determination of the particle-size distribution for aggregate. Grading limits and maximum aggregate size are specified because these properties affect the amount of aggregate used as well as cement and water requirements, workability, pumpability, and durability of concrete.