What is the design air void content as per the Marshall method of bituminous mix design?

Air voids (Va), sometimes expressed as voids in the total mix (VTM) Voids in the mineral aggregate (VMA) Voids filled with asphalt (VFA)…Density and Voids Analysis.

Nominal Maximum Particle Size	Minimum VMA (percent)
12.5	0.5 inch	15
9.5	0.375 inch	16
4.75	No. 4 sieve	18
2.36	No. 8 sieve	21

What is the main objective of Marshall test?

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 the purpose of conducting Marshall stability test?

This test attempts to get the optimum binder content for the aggregate mix type and traffic intensity. This is a test which helps us to draw the Marshall stability vs. % of bitumen.

What is the significance of stability and flow value in Marshall test?

The flow value refers to the vertical deformation when the maximum load is reached. Marshall stability is related to the resistance of bituminous materials to distortion, displacement, rutting and shearing stresses. The stability is derived mainly from internal friction and cohesion.

Why Marshall mix design is done?

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 are two major features of the Marshall method of mix design?

The two principle features of the Marshall method of mix design are a density-voids analysis and a stability-flow test of the compacted test specimens. The stability of the test specimen is the maximum load resistance in Newtons that the standard test specimen will develop at 60°C when tested as outlined.

Which are the two major parameters considered in the Marshall mix design?

9. Which are the two major parameters considered in the Marshall mix design? Explanation: Density and stability are the two important features that are used in the Marshall mix design procedure.

How do you perform a Marshall stability test?

The basic Marshall test consists essentially of crushing a cylinder of bituminous material between two semi-circular test heads and recording the maximum load achieved (i.e. the stability) and the deflection at which the maximum load occurs (i.e. the flow).

At what rate load is applied on Marshall stability machine is?

MS-87 Marshall Stability Load Frame has a fixed 2in (50.8mm) per minute loading rate, 20,000lbf (89kN) capacity and operates at 200-240V/50-60Hz. The loading rate for all models is maintained at ±1% by the 1hp DC motor and controller.

What is the result of Marshall stability test?

The laboratory results indicate that bituminous concrete prepared by 4 % cement coated OBBA gives the highest Marshall stability. The bituminous concrete mix with 4 % cement shows considerable improvement in various mechanical properties of the mix compared to the plain OBBA concrete mix.

How do you do the Marshall stability test?

What is flow in Marshall mix design?

Determine Marshall stability and flow While the stability test is in progress dial gauge is used to measure the vertical deformation of the specimen. The deformation at the failure point expressed in units of 0.25 mm is called the Marshall flow value of the specimen.

What are two features of Marshall mix design?

The Marshall method of Designing analyses two features of pavement bituminous mixes: 1. Stability- Flow Analysis 2. Density- Voids Analysis. The stability and flow values are directly recorded during the test. These will inform the maximum load which the mix can take before deforming to failure.

Who is the inventor of the Marshall mix?

3. INTRODUCTION The basic concepts of the Marshall mix design method were originally developed by Bruce Marshall of the Mississippi Highway Department around 1939 and then refined by the U.S. Army. The Marshall stability and flow test provides the performance prediction measure for the Marshall mix design method.

How is deformation recorded in a Marshall mix?

The deformation is also recorded as the flow value in units of 0.25mm. This is repeated for a number of specimens with the same grade of aggregates but different asphalt contents. The Marshall method of Designing analyses two features of pavement bituminous mixes: 1. Stability- Flow Analysis 2. Density- Voids Analysis.

What is the sample preparation procedure for Marshall mix?

The standard Marshall method sample preparation procedure is contained in: AASHTO T 245: Resistance to Plastic Flow of Bituminous Mixtures Using the Marshall Apparatus The Marshall stability and flow test provides the performance prediction measure for the Marshall mix design method.

What is the design air void content as per the Marshall method of bituminous mix design? Air voids (Va), sometimes expressed as voids in the total mix (VTM) Voids in the mineral aggregate (VMA) Voids filled with asphalt (VFA)…Density and Voids Analysis. Nominal Maximum Particle Size Minimum VMA (percent) 12.5 0.5 inch 15 9.5 0.375…