Density is also called the unit weight of a substance. It is represented by a symbol called a line (p). Density represents the degree of compactness of a material. If the material is of higher density, it is more compacted material.
The density of construction materials is their Mass per unit volume of materials. It is expressed in kg / m3 or lb / ft3 and shows the compactness of the construction material.
The density can be expressed as
- p = m/V = 1/v
- p = density [kg / m3], [slugs / ft3]
- m = mass [kg], [slugs]
- V = volume [m3], [ft3]
- v = specific volume [m3 / kg], [ft3 / slug]
- Conversion: 1 kg / m3 = 0.624 lb / ft3
A cement is a binder, a substance used in construction that hardens, hardens and adheres to other materials to join them together. Cement is rarely used on its own, but to bond sand and gravel.
First, density is the ratio of mass to volume. So it can be indicated in terms of kg / m3, which is 1440kg / m3 for cement. Therefore, density is found for materials and not for certain quantities.
The Density of Sand utility returns sand density based on sand conditions (wet/dry in bulk / packaged).
The density of the sand is affected if the sand is compacted (bulged) or loose and if it is wet or dry. When packed, the grains of sand are forced to form a narrower formation, and more matter is in the volume.
When the sand is wet, the water is in the sand, also affecting the total matter in the volume. The average density of the different sand conditions is as follows:
- Loose sand: 1442 kg / m3. It is dry sand that has been moved or agitated to loosen the natural packaging process.
- Dry sand: 1602 kg / m3. It is sand in its undisturbed natural form, where it has been partially compacted by rain and gravity over time, but is now dry
- Packed sand: 1682 kg / m3. Sand that has been packed manually or mechanically (compacted)
- Wet sand: 1922 kg / m3. This is the sand that has been in a natural and naturally compressed environment that is now wet.
- Wet packed sand: 2082 kg / m3. This is compacted sand that is also almost saturated with water.
Also, read: 10 Best Cement Companies In India
The aggregate is an aggregation of non-metallic minerals obtained in the form of particles and can be processed and used in the construction of civil and road engineering.
Aggregates Are Mainly Classified into Two Categories:
- Fine aggregate
- Coarse aggregate
The fine aggregate is natural sand that has been washed and sieved to remove particles larger than 5 mm, and the coarse aggregate is a gravel that has been crushed, washed and sieved so that the particles vary from 5 to 50 mm in size. The fine and coarse aggregate is delivered separately.
As they need to be sieved, a prepared mixture of fine and coarse aggregate is more expensive than the natural all-in aggregate.
The reason for using a mixture of fine and coarse aggregate is that by combining them in the correct proportions, concrete with very few voids or spaces can be made, and this reduces the amount of comparatively expensive cement needed to produce strong concrete.
Bulk Density of the Aggregate
The apparent density or unit weight of an aggregate is the Mass or weight of the aggregate needed to fill a container with a specified unit volume.
Bulk density = Mass / volume
If the volume is one unit, Bulk density = Mass.
Unit in kg / m3 or lb / ft3.
In this definition, the volume contains the aggregates and the voids between the aggregate particles.
The approximate apparent density of the aggregate that is commonly used in normal-weight concrete is between 1200-1750 kg / m3 (75-110 lb / ft3).
Here, the standard test method for determining the apparent density of aggregates is presented in the ASTM C 29 (AASHTO T 19) standard.
The relative density of aggregate
The relative density (specific gravity) of an aggregate is the ratio between its Mass and the Mass of an equal volume of water.
Relative density = Mass of the aggregate / Mass with an equal volume of water
Most aggregates have a relative density between 2.4-2.9 with a corresponding particle density (Mass) of 2400-2900 kg / m3 (150-181 lb / ft3).
Here, for coarse aggregates, the standard test method was explained in ASTM C 127 (AASHTO), and, for fine aggregates, the standard test method was explained in ASTM C 128 (AASHTO).
The relative density of an aggregate can be determined on an oven-dried basis or on a dry saturated surface (SSD).
Density Values of Different Building Materials
Density of Civil Martials
|Construction Materials||Density (Kg /m3)||Density (lb/ft3)|
|Bamboo||300 — 400||18.7 – 25|
|Pine||370 – 530||23 – 33|
|African mahogany||495 – 850||31 – 53|
|apple||660 – 830||1.2 – 51.8|
|Ebony||960-1120||59.9 – 69.9|
|Elm||600 – 815||37.4 – 50.8|
|Carvalho||590 – 930||36.8 – 58|
|Teak||630 – 720 3||9.3 – 44.9|
|Lignum vitae||1280 – 1370||79.9 -85.5|
|Igneous (felsic) rocks||2700||168.5|
|Igneous (mafic) rocks||3000||187.2|
|Stainless steel||7480-8000||466.9- 499.4|
Density also decides the sinking property of a material. It is decided by knowing the density of the liquid. If the material has a lower density than the liquid, it will float on the surface of a liquid. If it is denser than the liquid, it will sink.
If two different materials have the same weight, but the density of both can be different. The lower dense material occupies more volume than the higher dense material.
The value of the density of the building material will also help to discover the amount of material needed for a specific space.
For example, water has a density of 1000kg / m3; if we put bamboo wood (350kg / m3) in the water, it will float on the water surface in the same way; if we drop a brick (1700 kg.m3), it will sink into the water.
The density of different building materials is listed below.
There are many building materials used in construction. In the table above, we try to cover the unit weight of the building materials that are most commonly used on the construction site.