What is Marshall test on asphalt?

The Marshall Test is a popular and proven method to measure the load and flow rate of asphalt specimens, beginning with compaction into molds using manual or automated Marshall Compactors, and conditioned in a Water Bath at the specified temperature.

What is Marshall in asphalt?

The "Marshall" in Marshall Stability Test refers to Marshall mix, which is the type of asphalt we see in roads today. The Marshall mix design method helps engineers select the optimum asphalt binder content at a density that meets stability and flow value requirements.

What is the Marshall stability test?

Marshal stability test is the performance prediction measure conducted on the bituminous nix. The procedure consists of determination of properties of mix, Marshal stability and flow analysis and finally determination of optimum bitumen content. The concept of phase diagram is used for the calculations.

What is Marshall flow test?

The Marshall stability and flow test provides the performance prediction measure for the Marshall mix design method. The stability portion of the test measures the maximum load supported by the test specimen at a loading rate of 50.8 mm/minute (2 inches/minute).

Why is the Marshall stability test for asphalt important?

Marshall Stability alone, however, is not an absolute measure of strength. It is believed that the results of this analysis will be very useful in highway and airfield design. All of these are used to measure plastic stability or the ability of a mix to resist being squeezed out from under a load.

Marshal Stability Test Tutorial

Why do we do Marshall test?

The Marshall Test measures the load and flow rate of asphalt samples. Because not all asphalt is created the same, engineers need to predict how well an asphalt mixture will perform in addition to the maximum load it can support.

What is Marshall stability of bitumen?

The Marshall Stability of the bituminous mix specimen is defined as a maximum load carried in kg at the standard test temperature of 60°C when load is applies under specified test conditions. The flow value is the total deformation of Marshall Test specimen at the maximum load, expressed in mm units.

How do you perform a Marshall stability test?

What is Marshall method of bituminous mix design?

The Marshall Mix Design method was originally developed by Bruce Marshall of the Mississippi Highway Department in 1939. The main idea of the Marshall Mix Design method involves the selection of the asphalt binder content with a suitable density which satisfies minimum stability and range of flow values.

What is GMM in asphalt?

Gmm = maximum specific gravity of paving mixture (no air voids) Pmm = total loose mixture = 100% Ps = aggregate, percent by total weight of mixture (P1 + P2 + P3 + Pn) Pb = asphalt, percent by total weight of mixture. Gse = effective specific gravity of aggregate. Gb = specific gravity of asphalt.

How is Marshall mix design calculated?

Gmm = maximum specific gravity of paving mixture (no air voids) Pmm = total loose mixture = 100% Ps = aggregate, percent by total weight of mixture (P1 + P2 + P3 + Pn) Pb = asphalt, percent by total weight of mixture. Gse = effective specific gravity of aggregate.

What is stability and flow of asphalt?

The results show that the Marshall stability for the asphalt concrete with mineral filler ranges from 5.89 – 7.90 kN while that with hydrated lime ranges from 5.9 to 8.2 kN. The flow values for the asphalt concrete with mineral filler range from 2.3 mm – 3.3 mm, while that with hydrated lime range from 2.4 – 3.4 mm.

What is the Marshall Value?

The marshal stability value is defined as maximum load carried by a compact specimen at a standard temperature of 60 ⁰C. The stability and void requirement of bituminous mix are tabulated below. These values are to be satisfied while designing the mix.

What is the stability of asphalt?

Stability of a hot mix asphalt pavement is the ability to resist shoving and rutting under traffic. A stable pavement maintains its shape and smoothness under repeated loading. Stability requirements should be high enough to handle traffic, but not so high as to result in a stiff pavement that is less durable.

What is softening point test?

Softening point test of bitumen is done to determine the consistency of bitumen. This test gives an idea of the temperature at which the bitumen attains certain viscosity.

What is a rice number for asphalt?

This value is based on the asphalt mixture's maximum specific gravity – also known as the Rice value or G mm in Superpave. The maximum unit weight is determined by multiplying the Rice value by 62.4 pounds per cubic foot (PCF). For example, 2.500 is a typical Rice value. 2.500 X 62.4 = 156.0 PCF.

What is flow in asphalt?

The flow number (N) is an empirical way of characterizing a hot-mix asphalt (HMA) mixture's rutting potential. To determine the flow number, a cyclic load in haversine form is applied on a cylindrical specimen axially as shown in Figure 1.

What is TMD in asphalt?

Theoretical maximum specific gravity is a critical HMA characteristic because it is used to calculate percent air voids in compacted HMA. This calculation is used both in Superpave mix design and determination of in-place air voids in the field.

What is VFA in asphalt?

The VFA is the percentage of voids in the compacted aggregate mass that are filled with asphalt cement. It is synonymous with the asphalt-void ratio. The VFA property is important not only as a measure of relative durability, but also because there is an excellent correlation between it and percent density.

What is GMB and GMM?

• Gmb= bulk specific gravity of the mixture. • Gmm= theoretical maximum specific gravity of the mixture.

What is BRD asphalt?

Bulk density and void content

Known as BRD, this test determines the density of the hot mix asphalt mix after compaction.

What is the 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 dust to binder ratio?

During design, mixtures that are above the maximum density line at the 2.36-mm (for 19-mm or smaller mixtures) or 4.75-mm (for 25-mm or larger mixtures) critical sieve should have a dust-to-binder ratio of no more than 1.4.

What is VMA and VFA?

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.

How do you increase VMA in asphalt?

Work by the Asphalt Institute evaluated the drawing of maximum density lines on a 0.45 power chart for both gravel and crushed limestone mixtures. Lowering the dust content in a mixture will increase the VMA.