MARSHALL STABILITY TEST APPARATUS AZA0953

Description

Principle of Operation

A standard cylindrical Marshall specimen, prepared and compacted as per relevant standards, is first conditioned to the specified test temperature—commonly 60 °C—using an external water bath or air oven. The conditioned specimen is then placed in a semi-circular steel Marshall breaking head mounted within the rigid load frame.

A hand-operated or motor-driven loading ram applies a continuous vertical compressive load at a controlled rate of 50.8 mm/min (2 inches/min) until specimen failure. During loading:

• The maximum load sustained by the specimen is recorded as Marshall Stability

• The total vertical deformation at the point of maximum load is recorded as Marshall Flow

These values are essential for determining the optimum bitumen content and overall suitability of the asphalt mix for pavement construction.

Measurement System

Load Measurement (Stability):

• Achieved using a calibrated proving ring fitted with a high-sensitivity dial gauge

• Indicates the peak load at failure, directly representing the stability of the mix

Deformation Measurement (Flow):

• Measured using a dedicated flow dial gauge mounted to record vertical deformation

• Represents the flexibility and deformation tolerance of the bituminous mix

The system ensures consistent loading rates and repeatable results, making the AZA0953 suitable for routine laboratory testing and project quality assurance.

Construction and Design Features

• Heavy-duty rigid steel load frame ensuring accurate force transmission

• Smooth-operating loading ram for uniform load application

• Precision-calibrated proving ring and flow dial gauge

• High-quality steel Marshall breaking head for standard 101.6 mm specimens

• Robust, low-maintenance construction for long-term laboratory use

• Cost-effective alternative to fully automatic Marshall testing systems

Engineering Significance

The results obtained using the AZA0953 play a vital role in asphalt pavement engineering:

• Optimum Mix Design: Determines the correct balance between strength and flexibility

• Rutting Resistance: Higher stability values indicate improved resistance to deformation under heavy traffic and elevated temperatures

• Fatigue and Crack Resistance: Proper flow values ensure durability against repeated loading and thermal stresses

• Quality Control & Acceptance: Essential for verifying compliance of plant-produced asphalt mixes with approved design specifications

The apparatus is extensively used by highway authorities, consultants, contractors, and academic institutions across India.

Standards Compliance

The AZA0953 conforms to the requirements and principles of the following standards:

• IS 2720 (Part 10) – Determination of Stability and Flow of Bituminous Mixes (Marshall Test)

• ASTM D1559 / ASTM D6927 (methodological alignment)

• AASHTO T245 (methodological alignment)

• MoRTH Specifications and IRC guidelines (application-based compliance)

Technical Specifications

Model Number: AZA0953
Test Method: Marshall Stability and Flow Test (Manual / Semi-Automatic)
Loading Capacity:

• 25 kN or 50 kN (2500 kgf or 5000 kgf), via proving ring

Loading Rate:

• 50.8 mm/min (2 inches/min), hand-operated or motor-driven

Load Measurement:

• Proving Ring with dial gauge (typical least count: 0.002 mm)

Flow Measurement:

• Dial Gauge, 0–25 mm range

• Typical least count: 0.01 mm

Specimen Size:

• 101.6 mm (4-inch) diameter Marshall specimens

Breaking Head:

• Hardened steel, semi-circular type

Temperature Conditioning:

• External water bath or air oven required

• Typical test temperature: 60 °C

• Compatible with AZA0958 Marshall Water Bath

Power Supply (Motorized Version):

• 230 V AC, 50 Hz, Single Phase

Load Frame:

• Heavy-duty steel construction

Included Accessories:

• Proving Ring

• Flow Dial Gauge

• Marshall Breaking Head

• User Manual

Key Features & Benefits

• Manual operation ensures reliability and economical testing

• High precision measurement using proving ring and dial gauges

• Fully compliant with essential Indian and international standards

• Durable construction for continuous laboratory use

• Essential quality control tool for asphalt mix design and verification

Frequently Asked Questions (FAQ)

Q1. What is the primary purpose of the AZA0953?
It is used to determine Marshall stability and flow values of compacted bituminous mixtures for asphalt pavement design and quality control.

Q2. How are stability and flow measured?
Stability is measured using a calibrated proving ring that records maximum load, while flow is measured using a dial gauge that records vertical deformation at peak load.

Q3. How does AZA0953 differ from automatic Marshall testers?
AZA0953 requires manual observation and recording of readings, whereas automatic testers use digital sensors and software. AZA0953 is more economical and widely preferred for routine testing.

Q4. Does the apparatus require a water bath?
Yes. Specimens must be conditioned at the specified temperature (typically 60 °C) using an external water bath or air oven.

Q5. How does AZA0953 contribute to road quality in India?
It ensures asphalt mixes meet strength and deformation requirements suitable for Indian traffic and climatic conditions, resulting in longer-lasting and rut-resistant pavements.