around 1.03
Because the specific gravity of asphalt binders change with temperature, specific gravity tests are useful in making volume corrections based on temperature. The specific gravity at 15.6° C (60° F) is commonly used when buying/selling asphalt cements. A typical specific gravity for asphalt is around 1.03.
What is the density of asphalt binder?
1.00 g/cm3
The mixing temperature range is defined as the range of temperature where the unaged asphalt binder has a kinematic viscosity of 170 + 20 mm2/s (approximately 0.17 + 0.02 Pa-s for an asphalt binder density of 1.00 g/cm3) measured in accordance with ASTM D 4402.
How do you find the specific gravity of coarse aggregate?
Apparent Specific Gravity of Aggregates: It is calculated by measuring the weight of the oven-dry aggregate divided by its absolute volume excluding the natural voids in the aggregate particles.
What is maximum specific gravity?
Overview. The theoretical maximum specific gravity (Gmm) of a HMA mixture is the specific gravity excluding air voids. Theoretical maximum specific gravity is then the sample weight divided by its volume.
Why do we test specific gravity?
A urine specific gravity test compares the density of urine to the density of water. This quick test can help determine how well your kidneys are diluting your urine. Urine that’s too concentrated could mean that your kidneys aren’t functioning properly or that you aren’t drinking enough water.
What is the typical density of asphalt?
Standard density for asphalt is 145 lb/ft3 (2322 kg/m3). Multiply the volume by the density (in the same units) to get the weight.
What is the compaction rate of asphalt?
Remember, the compaction rate, as a general rule, is about 6 mm (1/4″) per 25 mm (1″) of screed laid thickness when a vibratory screed is used and about 5 mm (1/5″) per 25 mm (1″) when a tamping and vibrating screed is used.
Why do we find specific gravity of coarse aggregate?
Specific Gravity is important for several reasons. Some deleterious particles are lighter than the good aggregates. Specific gravity is critical information for the Hot Mix Asphalt Design Engineer. The value is used in calculating air voids, voids in mineral aggregate (VMA), and voids filled by asphalt (VFA).
What do you mean by specific gravity?
specific gravity, also called relative density, ratio of the density of a substance to that of a standard substance. Because it is the ratio of two quantities that have the same dimensions (mass per unit volume), specific gravity has no dimension.
How do you calculate specific gravity of bitumen?
The specific gravity of semi-solid bituminous material, asphalt cements, and soft tar pitches shall be expressed as the ratio of the mass of a given volume of the material at 25 °C to that of an equal volume of water at the same temperature.
What is the maximum specific gravity of asphalt?
Typical values for theoretical maximum specific gravity range from approximately 2.400 to 2.700 depending on the aggregate specific gravity and asphalt binder content. Unusually light or heavy aggregates may result in a value outside this typical range.
How does asphalt binder content affect asphalt compaction?
For instance, if adequate compaction is not being achieved, increasing asphalt binder content will fill more voids with asphalt binder and thus lower the air void content for the same amount of compaction. However, increased asphalt binder content can also potentially make a HMA mixture more likely to rut or shove. Figure 2: HMA compaction.
What is the theoretical maximum specific gravity of a HMA mixture?
The theoretical maximum specific gravity (Gmm) of a HMA mixture is the specific gravity excluding air voids. Thus, theoretically, if all the air voids were eliminated from an HMA sample, the combined specific gravity of the remaining aggregate and asphalt binder would be the theoretical maximum specific gravity.
How is the air density of a pavement determined?
Each time density is to be determined a measure of bulk specific gravity is made by either coring the pavement and determining bulk specific gravity on the sample or using a non-destructive testing method. This bulk specific gravity is then compared to the most current theoretical maximum specific gravity to determine air voids.
