About Marshall Stability and Compaction
Marshall Stability and Compaction
Originally developed by Bruce Marshall, a highway engineer in U.S.A later on standardized by ASTM. Generally the test is applicable to hot mix designs using bitumen and aggregates up to a maximum size of 25 mm.
In this method the resistance to plastic deformation of cylindrical specimen of bituminous mixture is measured when the same is loaded at
periphery at 5 cm per min. This test procedure is used in designing and evaluating bituminous paving mixes. The test procedure is extensively used in routine test programmer for paving jobs There are two major features of the Marshall method of designing mixes namely.
- Density voids analysis
- Stability flow tests.
The marshall stability of mix is defined as a maximum load carried by a compacted specimen at a standard test temperature of 60 deg.C. The flow value is deformation the marshall test specimen under goes during the loading upto the maximum load, in 0.25 mm units. In this test and attempt is made to determine optimum binder content for the type of aggregate mix and traffic intensity.
The apparatus consists of: 1. A loading unit motorized, capacity 5000 kg with two telescopic pillars and an adjustable cross head Limit switches are fitted inside to control upward or downward movement of the pillars. On off reversing switch and indicator lamps are on the front side while a hand wheel to manulally move the pillars minute operated on 230 Volts A.C.
- 1 No. Compaction pedestal with specimen mould holder.
- 2 Nos. Compaction Rammers, 4.5 kg weight and free fall 45.7 cm.
- 1 No. Breaking head assembly with provision to fix flow meter.
- 3 No. Specimen mould 10.16 cm I.D. x 7.6 cm high with base plate and extension collar.
- 1 No. Kit for specimen extraction, consists of one each load transfer bar, steel ball, specimen exacting plate.
- Flow meter (dial gauge) grasuated 0.01 mm x 25 mm travel.
- Fitted with a stem brake unit to indicate maximum deflection Complete as above.
Accessories :-
High sensitivity proving Ring 2500 kg capacity fitted with 0.002 mm dial gauge and our own test certificate. Complete in a nice wooden carrying case.
Advanced Digital Control and Programmable FeaturesThe apparatus integrates an intuitive digital LCD interface with programmable blow counting (0999), ensuring flexible operation during the compaction of bituminous samples. The digital control system promotes accurate, repeatable procedures, minimizing human error and maximising efficiency.
Robust Design and Comprehensive SafetyConstructed from durable mild steel, the machine offers consistent performance in challenging environments. Automatic overload cutoff mechanisms enhance operator safety, protecting both user and instrument during high-load testing. The solid build quality, coupled with safety features, provide peace of mind during extended use.
Precision Testing for Asphalt ApplicationsWith a load cell sensor, accuracy rated at 0.1%, and a calibrated travel rate of 50.8 mm/min, this apparatus is engineered for critical evaluations of asphalt and bitumen mixes. The collected data enables engineers to make informed decisions about pavement materials, supporting quality infrastructure development.
FAQs of Marshall Stability and Compaction:
Q: How is the Marshall Stability and Compaction test conducted using this apparatus?
A: The test involves compacting bituminous mix samples with the 4.5 kg hammer at a 457 mm drop height, using the digital LCD to set the required number of blows. The mould size is 101.6 mm diameter by 63.5 mm height. After compaction, the sample is placed in the load frame to measure stability and flow properties under controlled loading.
Q: What types of samples can be tested with this machine?
A: This equipment is specifically designed to test bituminous mixes for asphalt and bitumen applications. Its accessories and versatile settings allow for industry-standard sample preparation as per road construction and related material specifications.
Q: When should I use the automatic stop feature during testing?
A: The automatic stop feature is activated during overload conditions, ensuring operator safety and protecting the machine from excess stress. It should be used whenever there is a risk of surpassing the 50 kN load capacity or abnormal conditions during sample testing.
Q: Where can the Marshall Stability and Compaction apparatus be installed?
A: Thanks to its compact dimensions (775 x 225 x 800 mm) and robust construction, the machine is suitable for laboratory, industrial, and research center installations. It operates efficiently within an ambient temperature range of 10C to 40C.
Q: What processes are included in the Marshall Stability and Compaction test using this equipment?
A: Key processes include precise compaction of bituminous samples, programmable hammer operation, stability measurement via digital load cell, and data recording on the digital indicator. The machine covers sample preparation, loading, compacting, and analysis stages comprehensively.
Q: How do the programmable digital features benefit my testing workflow?
A: The digital LCD display and programmable blow setting (0999) streamline operations, offering clear data, adjustable settings, and strong reliability. Automatic cutoff and load display features further enhance convenience and reduce operator workload, speeding up laboratory workflow and improving accuracy.
Q: What accessories are supplied with the Marshall Stability and Compaction machine?
A: The apparatus comes complete with all necessary accessories: compaction hammer, breaking head, mould, base plate, load frame, and digital indicator. This inclusive package ensures a seamless setup and ready-to-use functionality for immediate testing.