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This test is done to determine the Marshall stability of bituminous mixture. The principle of this test is that Marshall Stability is the resistance to plastic flow of cylindrical specimens of a bituminous mixture loaded on the lateral surface at 5 cm per minute.
It is the load carrying capacity of the mix at 60 degree and is measured in kg. The sample needed is From Marshall stability graph, select proportions of coarse aggregates, fine aggregates and filler in such a way, so as to fulfill the required specification. The total weight of the mix should be gm for one specimen. The major features of the Marshall Method of designing mixes are to determine the two important properties of strength and flexibility.
This temperature represents the weakest condition for a bituminous pavement in use. In this test an attempt is made to obtain optimum binder content for the aggregate mix type and traffic intensity. They are designed to be interchanged with either end of cylindrical mould. Three mould cylinders are recommended. Specimen extractor for extracting the compacted specimen from the mould.
A suitable bar is required to transfer load from the extension collar to the upper proving ring attachment while extracting the specimen Compaction Rammers having a flat circular tamping face 4. Two compaction rammers are recommended. Compaction pedestal consisting of a 20 x 20 x 45 cm wooden block capped with a 30 30 x 2. Mould holder is provided consisting of spring tension device designed to hold compaction mould in place on the compaction pedestal.
Breaking head. The Breaking head consist of upper and lower cylindrical segments or test heads having an inside radius curvature of 5 cm. The lower segment is mounted on a base having two perpendicular guide rods which facilitate insertion in the holes of upper test segments.
Recalibrated proving ring of 5 tone capacity is fixed on the upper end of the machine, specimen contained in the test head is placed in between the base and the proving ring. Machine is capable of reversing its movement downward also. This facilitates adequate space for placing test head system. After one specimen has been tested.
Flow Meter. The flow meter consists of guide sieve and a gauge. The activating pin of the gauge slides inside the guide sleeve with a slide amount f fractional resistance. Least count of 0. The flow value refer top the total vertical upward movement form the initial position at zero load to value at maximum load.
The dial; gauge at the flow meter should be able to measure accurately the total vertical movement upward. In addition to the above the following general equipments are also required Oven or hot plates Mixing Apparatus Water Bath Thermometer of range up to C with sensitively of 2.
The required quantity of the mix is taken so as to produce compacted bituminous mix specimens of thickness Take gm of coarse aggregates, fine aggregates and filler material as per grading requirement given in table to produce the desired thickness. The total quantity of mix is placed in a mould and compacted by rammer with 75 blows.
Invert the sample, and compact the other face with the same number of blows. After compaction, invert the mould. With the collar of the bottom, remove the base and extract the sample by pushing it out the extractor.
The compacted specimen should have a thickness of Allow the sample to stand for a few hours to cool. NOTES: At least 2 specimens but preferably 3 or 4 specimen for each combination of aggregate and bitumen should be prepared. For surface course with 12 mm aggregate , the expected optimum bitumen content may be about 6. Therefore specimen should be made at 5. Remove the specimens from the water bath or oven and place the lower segment of the breaking head. Then place the upper segment of the breaking head on the specimen and place the complete assembly in position of the Marshall testing machine.
Place the flow meter dial gauge over one of the post and adjust into read zero. Apply a load at a rate of 50 mm per minute until the maximum load reading is obtained. Record the maximum load in Newton N. At the same instant obtain the flow as recorded on the flow meter in unit of mm.
The total time between removing the specimen from the bath and completion of the test should not exceed 30 seconds. Volume-thickness relationship is based on a specimen diameter of 10 cm. Detailed procedure along with calculations, correction factors etc is attached below.
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ASTM D 1559 - Resistance to Plastic Flow of Bituminous Mixtures Using Marshall Apparatus
The 50kN capacity and fully variable speed of 0. The load jack, DC motor and controls are housed in an ergonomic cabinet. Prior to the test, the operator can impose travel limits for automatically ending the test. No external transducer is required for displacement measurement. The firmware allows performance of transducer calibrations and setting of up to 10 test profiles, saving data onboard. A real-time test graph and transducer data are displayed on the touchscreen.
Marshall Stability Test as per ASTM D 1559 & IRC 111
All the process you described in this post is fantastic thanks for sharing this valuable info with us. IS : — PA SP : 11 — IS: IS : — Part — IS : Bruce Marshall, a former Bituminous Engineer with the Mississippi State Highway Department, formulated the concepts of the Marshall method of designing paving mixtures.