What is the specific gravity for asphalt?
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 specific 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 percent of asphalt is oil?
Asphalt emulsions that contain about 70% petroleum asphalt and 30% water plus a small amount of chemical additives.
What is VMA and VFA in asphalt?
Let’s look at VMA, which stands for “Voids in Mineral Aggregate.” VMA is the space between the rocks that can be filled with asphalt. The space filled with asphalt is known as VFA (Voids Filled with Asphalt). The remaining space is air voids. VMA is critical to a mixture’s durability and crack resistance.
What is GMM and GMB in asphalt?
• Gmb= bulk specific gravity of the mixture. • Gmm= theoretical maximum specific gravity of the mixture.
How is asphalt content calculated?
The asphalt content is calculated as the difference between the initial mass of the asphalt paving mixture and the mass of the residual aggregate, and the calibration factor. The asphalt content is expressed as mass percent.
What is the unit weight of asphalt?
142 to 148 pounds per cubic foot
Asphalt Mixture typically weighs from 142 to 148 pounds per cubic foot (PCF) in-place. Use 148 PCF. Calculate the tonnage needed. (remember to convert from pounds to tons; 2000 pounds per ton).
Is there oil in asphalt?
Asphalt occurs naturally in a few places in the world, but most of the asphalt used today for paving comes from petroleum crude oil. Asphalt is the heaviest part of the crude—what’s left after all the volatile, light fractions are distilled off for products such as gasoline.
Can asphalt be turned into oil?
The end product from the process can easily be refined into high-grade petroleum and other fuels. At present, oil refineries produce countless tons of bitumen residue every year that have little practical use or economic benefit and are an environmental hazard.
Why is VFA important in asphalt?
The purpose for the VFA is to avoid less durable HMA resulting from thin films of binder on the aggregate particles in light traffic situations. Voids in the mineral aggregate (VMA) are the air-void spaces that exist between the aggregate particles in a compacted paving mixture, including spaces filled with asphalt.
How do you calculate VFA in asphalt?
VFA = (VMA-Va)/VMA x 100 ▪ VMA = 100 – (Gmb x Ps)/Gsb ▪ Va = (Gmm-Gmb)/Gmm x 100 ▪ Pba = 100 x ((Gse-Gsb)/(Gsb x Gse)) x Gb ▪ Gse = (100-Pb)/((100/Gmm)-(Pb/Gb)) ▪ Pbe = Pb-(Pba/100) x Ps Page 24 ▪ What goes into determining the volumetric properties of a mix?
What is maximum specific gravity?
The theoretical maximum specific gravity of a bituminous mixture is the bulk specific gravity of that mixture when compacted to the point of zero air voids.
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. Calculate and report Gmm to the nearest thousandth.
What is the air void content of an asphalt mixture?
The air void content of an asphalt mixture is an integral component of all other volumetric properties. Historically, properly designed air voids and VMA are excellent indicators of long-term performance. An air void content out of tolerance on the high side indicates that the mix will likely be difficult to compact in the field as well.
How do you calculate GMM in asphalt?
Gmm is the Theoretical Maximum Specific Gravity of an asphalt mixture, sometimes referred to as “Rice’s gravity.” The Gmm of a field sample is typically determined by AASHTO T 209 to calculate the asphalt mix volumetrics. Gmm can also be mathematically calculated by the following equation: Gmm – 100 / (Ps / Gse + Pb / Gb )
What does an asphalt test report look like?
Some test reports say something like “pass” or “fail” for a few basic tests. Others contain all of the raw data, calculations and allowable tolerances for a multitude of tests. Some people are experts that can tell with a glance at a report exactly what a problem is, how to fix it, and how it will affect the asphalt’s long-term performance.