Tilok Chand Narsingh Lal

Civil Lines, Roorkee, Uttarakhand

used for conducting survey by total station.

We are prominently engaged in providing Marshall Test Apparatus to the customers. This Marshall Test Apparatus method covers the measurement of the resistance to plastic flow of cylindrical specimens of Bituminous paying mixtures loaded on the lateral surface by means of the Marshall Apparatus. This Marshall Test Apparatus method is for used with hot mixtures containing asphalt or far and aggregate up to 25mm maximum size.

Apparatus :Specimen Mould Assembly :

• Mould cylinders 4" (100mm) in diameter by 3 (76mm) in height, base plates, and extension collars shall confirm to the code. Three mould cylinders are recommended

• Specimen Extractor : A specimen extractor to remove the compacted specimen from the specimen moulds recommended. A suitable bar is required to transfer load from the extension collar through a circular steel plate (100mm dia x 12mm thick) supporting a steel rod of 25mm)

• Compaction Hammer : The compaction hammer shall have a flat, circular tamping face and a 103 B (4.5 kgs) sliding weight with a free fall of 18 inch, two compaction hammers are recommended

• Compaction Pedestal : The compaction pedestal shall consists of a 8" x 8" wooden post capped with a 12" x 12" x 1" steel plate. The wooden post shall be oak, yellow pine or other wood having a dry weight of 42 to 48 LBS per cuft. The wooden post shall be secured by four angle iron brackets to a solid concrete slab. The steel cap shall be installed properly so that the post is plumb/straight and cap is level

• Specimen Holder : The specimen holder shall consists of a semi circular base and a circular ring to hold the specimen mould in place during compaction of the specimen, the top section shall be flanged to fit over the collar of the specimen mould and shall be provided in the base for mounting on the compaction pedestal. The specimen mould holder shall be mounted on the pedestal steel cap so that the center of the mould is over the post

• Breaking Head : The breaking head assembly shall consist of upper and lower cylindrical segment or test heads having an inside radius or curvature of 2" accurately machines. The lower segment shall be mounted on a base having two perpendicular guide rods or posts extending upward. Guide sleeves in the upper segment shall be in such a position as to direct the two segments together without appreciable binding or loss of motion on the guide rods

• Loading Frame : The loading frame consists of a power operated screw jack mounted in a steel testing frame and shall produce a uniform vertical movement of 2" per minute the upward and downward movements are automatically controlled by Micro Switches. The testing (load) frame is also provided with a hand wheel (crank) for initialing adjustment or for applying loads in case of power failures

• Proving Ring Assembly : Own Proving Ring of 3000 kg capacity and sensitivity of 10 - 15 between and 2000 kg shall be equipped with micrometer dial. The micrometer shall be graduated in mms (0.002mm) Proving Ring attachments are required for fastening the Proving Ring to the testing frame and transmitting the load to the breaking head, suitable threads are provided in either side of the loading bosses of the Proving Ring for required fixing

Miscellaneous Equipments :

• Oven or Hot Plate : Oven or Hot Bath should be provided for heating aggregate bituminous material specimen moulds, compaction base etc, and other equipments required or mixing and moulding temperatures. It should recommended that the required temperature with 5F controlled so as to maintain the required temperature within 51 (2.8C) suitable shields, baffle plates or sand baths shall be used on the surfaces of the hot plates so minimize localized over-heating or exposure to cool air in winter

• Mixing Apparatus : Mechanical mixing is recommended. Any type of mechanical mixer may be used provided it can be maintained at the required mixing temperature and will produce a well coated, homogeneous mixture of the required amount in the allow-able time. A metal pan or bowl of sufficient capacity and hand mixing may also be used. Generally, specimen is prepared from the mixer of the hot plant or hot mix laid at site

• Water Bath : The Water Bath shall be at least 15cm deep and shall be thermostatically controlled so as to maintain the bath at 140-188F (60^oC) the tank shall have a perforated bottom or be equipped with a shelf for supporting specimen 5cm above the bottom of the bath

• Containers for heating bituminous material, either grill type tins, breakers pouring posts, or saucepans may be used
• Mixing tool-either steel trowel (Garden type) or spatula, for spreading and hand mixing
• Thermometers of determining temperature of aggregates, bitumen and bituminous mixture. Armored glass thermometers or dial type with Metal stem are recommended. A range of 9.9 to 400/500 F (2 to 24^oC) with sensitivity of 5F (2.8C) required
• Thermometers for Water Bath with a range of 6F to 158F (20 to 70C) sensitive to 0.4F i.e. 0.2^oC
• Balance 5 kg capacity, sensitive to 0.1gm for weighing molded specimens
• Balance 5 kg capacity, sensitive to 0.1gm for batching mixtures
• Rubber gloves for removing specimens from water bath
• Marketing pencils for identifying specimens
• Scoop flat bottom for batching aggregates
• Spoon (large) for placing mixtures in specimen moulds

Test Specimen :

• Number If Specimen : Prepare at least three specimens for each combination of aggregates and bitumen contents

• Preparation Of Aggregates : Dry aggregates to constant weight at 221 to 231 F (105 to 110 C) and prepare the aggregates by dry sieving into the desired size fractions. The following size fractions are recommended 25mm- 20mm, 20mm to 12.5mm, 12.5mm to 4.75mm and passing 2.36mm

• Determination Of Mixing : At compacting temperatures. The temperatures to which the asphalt must be heated to produce viscosity's of 85 to 10 sec saybolt favol and 140-15 sec saybolt farol shall be established as the mixing temperature and compaction temperature, respectively the corresponding viscosity's Farol shall be Englar specific viscosities of 25-3 for mixing and 40-5 for compacting

• Preparation Of Mixtures : Weight into separate pans for each test specimen, the amount to each size fraction required to produce a batch that will result in compact specimen 2.5"-3" in height (about 1200 G) place the pans on the hot plate or in the oven and that to a temperature of approximately 50 (27.8C) above the mixing bowl and with the heated aggregate and dry thoroughly, from a created in the dry blended aggregate and weight the required amount of a bituminous material into the mixture. At this point the temperature of the aggregate and bituminous material shall be within the limits of the mixing temperature established in paragraph below mix the aggregate and bituminous material rapidly until completely coated

• Compaction Of Specimen : Thoroughly clean the specimen moiled assembly and the fact of the hot plate to temperature between 200 and 300 F (93.3 and 148.9C) place a piece of filter paper or paper toweling cut to size in the bottom of the mould before the mixtures is introduced. Place the entire batch in the mould space the mixture vigorously with a heated spatula or trowel to a slightly rounded shape. Temperature of the mixture immediately prior to a compaction shall be within the limits of the compacting temperature established a under

• Place the collar and mould assembly on the compaction pedestal in the mould hold and unless otherwise specified, supply 50 blows with a compaction hammer with a free fall of 18 inch. Hold the axis of the compaction hammer perpendicular to the base of the mould assembly during compaction. Remove the base plate and collar and reverse the assembly of the mould. Apply the same number of compaction blows to the face of the reversed specimen. After compaction place the sample extractor plate on the end of the specimen. Place assembly with the extension collar down in the testing machine. Apply pressure by the load transfer bar and force the specimen into the extension collar. Lift the collar from the end of the specimen. Carefully transfer the specimen to smooth flat surface and allow it to stand overnight at room temperature. Weight measure and test the specimen. Table fans may be used. Mixtures that lack sufficient cohesion to result in the required cylindrical shape on removal from the mould immediately after compaction may be cooled, until rapidly cohesion has developed to result in the proper cylinder shape

Procdure :

• Bring the specimens to the desired temperature by immersing them in Water Bath and place the lower segment of the Breaking Head and place the complete assembly in position on the testing machine. Place the dial gauge in position over the support and adjust the gauge at zero while holding in firmly against the upper segment

• Apply load to the specimen by means of the constant rate of movement of the load jack or testing machine head at 2 in per minute head of 2 inch indicated by the dial. Record the maximum reached load decreased as indicated by the dial. Record the maximum load sauted on the testing machine or converted from the indicated flow. Recovery of test specimen from the Water Bath to the maximum load determination shall not exceed 30 seconds

• Keep the test sample in the Water Bath for 30 to 40 minutes, keep the samples in temperature at 140-188F for asphalt specimens and 100 to 118 F (37.8C) for tar specimen as in alternative the specimens may be brought to desired temperature by placing in an oven for minimum of 2 hours. Maintain the oven temperature at 140-188 F (60-70C) for asphalt specimen 100-108F (37.81C) for tar specimen. Thoroughly clean the guide rods and the inside surfaces for the test heads, proper to making the test and laborite the guide rods so that the upper test head slides freely over them. Remove the specimen from the water (for repeat test) and place in the breaking need assembly. Three samples (specimens) to be tested for each varying type mixtures

Report (Result) :The report shall include the following information for each specimen tested :

• Weights of the test specimen. Average of three (3) to be taken
• Maximum load in kgs corrected when required
• Flow value in hundredth of a millimeter
• Mixing temperature
• Compacting temperature and testing temperature

Geology Compass DQL-8 Specification : Geology Compass DQL-8 : Precision of Plate Level 20' 5' / 2 ( mm) Precision of Circular Level 30' 5' / 2 ( mm) Reading Error d0.5 Min. Graduation 1 Damping Time d15 "