Introduction of Bulk Density and % Voids of Coarse Aggregates
Bulk Density is the mass of a unit volume of material in its natural state with pores and voids not taken into account. The % Voids is the Total Volume of the Void spaces in the material expressed as a percentage of the overall volume. The information for both of these is generally determined on a dry basis.
There are a number of ways to test for bulk density and % voids, but the most common method is with the use of a Core Cutter. This method is generally used for materials such as concrete and asphalt.
The Core Cutter method involves cutting a cylindrical core of the material in question and then weighing it to determine the mass. The volume of the core is then determined by
What Is Bulk Density and % Voids of Coarse Aggregates
- The bulk density of coarse aggregates is the mass of dry solids that they contain per unit volume
- The percentage of voids is the amount of space that is not occupied by the solid particles.
What Is Bulk Density and Their Types
- Bulk density is one of the primary physical properties used to describe solid pharmaceuticals
- It is a measure of mass per unit of volume and is commonly expressed in grams per cubic centimetre
- The bulk density of a powder is often affected by the degree of packing of the powder particles and the amount of empty space between them
- It is an important property for powders intended for oral administration, since it influences therate of drug release from the powder and the behavior of the powder during mixing, tabletting and deagglomeration
- There are three main types of bulk density: tapped, loose and tap densities
- Tapped density is the bulk density that results when a powder is compacted by tapping or vibrating the container
- Loose density is the bulk density of a powder that has been allowed to settle under the force of gravity
- Tap density is a measure of the compactness of a powder and is determined by the difference between the tapped and loose densities.
Types of Bulk Density of Coarse Aggregate
- There are four types of bulk density of coarse aggregate:
Loose bulk density
This is the bulk density of the aggregate when it is not compacted.
Compacted bulk density
This is the bulk density of the aggregate when it is compacted.
Saturated surface dry bulk density
This is the bulk density of the aggregate when it is saturated with water and the surface is dry.
Submerged bulk density
This is the bulk density of the aggregate when it is submerged in water.
Types of Coarse Aggregate According to Packing
- The different types of coarse aggregate are distinguished according to their packing
- The four main types are:
- Open-graded aggregate: These have a high void content and are used to promote drainage.
- Standard-graded aggregate: These have a moderate void content and are used in general-purpose concrete.
- Dense-graded aggregate: These have a low void content and are used in concrete with a high compressive strength.
- heavyweight aggregate: These have a high unit weight and are used in concrete that needs to be especially dense or durable.
Conclusion
The bulk density and % voids of coarse aggregates is an important determination because it affects the amount of material in a concrete mix. The lower the bulk density, the higher the % voids and the lighter the weight of the concrete. The higher the bulk density, the lower the % voids and the heavier the weight of the concrete.
Frequently Asked Questions
What is the bulk density of coarse aggregates?
The bulk density of coarse aggregates is the mass of dry solids that they contain per unit volume. The percentage of voids is the amount of space that is not occupied by the solid particles.
What method is generally used to determine bulk density and % voids?
The most common method for determining bulk density and % voids is with the use of a Core Cutter.
What is bulk density and what are the different types of bulk density of coarse aggregate?
Bulk density is the mass of a unit volume of material in its natural state with pores and voids not taken into account. The different types of bulk density of coarse aggregate are loose bulk density, compacted bulk density, saturated surface dry bulk density, and submerged bulk density.
