3.1 Acceptable Acceptable to the authority administering this standard or to the parties concluding the purchase contract, as relevant.

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1 TEST PROCEDURE PROCEDURE FOR MANUFACTURING TEST SPECIMENS FROM BITUMEN STABILISED MATERIAL (BSM) USING VIBRATORY HAMMER COMPACTION (August 2016 Draft. Compiled by BSM Laboratories) 1 SCOPE This method describes the procedure for manufacturing test specimens from bitumen stabilised material (BSM) using a vibratory hammer to compact the material in a mould. 150mm and/or 152mm diameter specimens are manufactured using this method and the compaction target is 100% of the modified AASHTO (T-180) density (SANS 3001 Test Method GR30). To prevent damage during the extraction process, all specimens are manufactured in two-segment split moulds. The height of the specimen (and the number of component layers) is dictated by the test that will be conducted on the specimen. Each specimen is manufactured in a series of layers, each layer being approximately 50mm thick. With the exception of the final (uppermost) layer, uniformity across the interlayer joint is achieved by roughening the exposed surface of all compacted layers prior to adding material and compacting the next layer. 2 NORMATIVE REFERENCES The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Information on currently valid national and international standards can be obtained from the SABS Standards Division. SANS 3001 Test Method GR 20: Determination of the moisture content by oven-drying. SANS 3001 Test Method GR 30: Determination of the maximum dry density and optimum moisture content (AASHTO T Edition) SABITA publication TG2: Bitumen Stabilised Materials: o Determination of the Indirect Tensile Strength (ITS) of compacted and cured specimens of bitumen stabilised material. o Determination of the shear properties of compacted and cured specimens of bitumen stabilised material (simple monotonic triaxial test to determine Cohesion and Angle of Internal Friction). Operating manuals produced by the manufacturer of any equipment that is used to prepare the material for compaction. 3 DEFINITIONS For the purpose of this document, the following definitions apply: 3.1 Acceptable Acceptable to the authority administering this standard or to the parties concluding the purchase contract, as relevant. 3.2 Maximum Dry Density (MDD) The maximum dry density of the material determined from the peak of the dry density versus moisture content curve using the specified compaction effort to manufacture specimens of height 127mm and of diameter 152mm.

2 3.3 Optimum Moisture Content (OMC) The moisture content at which the maximum dry density is achieved. 3.4 Indirect Tensile Strength (ITS) of a bitumen stabilised material.

5 Shear properties (Cohesion and Angle of Internal Friction) The values of Cohesion ( C in kpa) and Angle of Internal Friction ( φ in degrees) determined from the Mohr-Coulomb circles after plotting

2 2 3.3 Optimum Moisture Content (OMC) The moisture content at which the maximum dry density is achieved. 3.4 Indirect Tensile Strength (ITS) of a bitumen stabilised material. The stress at failure generated by the load required to split a cylindrical specimen of height 95mm and of diameter 152mm at a constant displacement rate of 50.8mm/min. 3.5 Shear properties (Cohesion and Angle of Internal Friction) The values of Cohesion ( C in kpa) and Angle of Internal Friction ( φ in degrees) determined from the Mohr-Coulomb circles after plotting the vertical stress (σ 1 ) applied to specimens of height 300mm and of 150mm diameter at a constant displacement of 3mm/min under different confining pressures (σ 3 ). (Simple monotonic triaxial test.) 4 APPARATUS 4.1 A vibratory (demolition) hammer that conforms to the following specifications: Rated power input: 1700W Impact rate: min -1 Impact energy: 23 J per stroke (± 1 J) Mass: 11.5kg (± 0.1kg) (Note. The Bosch Demolition Hammer, GSH 11VC Professional is one example of a demolition hammer that meets these specifications.) 4.2 A shank fitted to the vibratory hammer with a 145mm (± 1.0mm) diameter tamping foot attachment with a combined mass of 3.0kg (± 0.1kg) 4.3 A frame with vertical slides, complete with mounting head for the vibratory hammer that allows the vibratory hammer to be suspended above the mould with the tamping foot centred on the mould. The slides must ensure free downward movement of the hammer as it compacts the material in the mould. The frame must also be fitted with a system (connected to the top of the frame) for lifting and lowering the vibratory hammer. The base of the frame must be bolted to a concrete block that is at least 1m x 1m and 300mm thick, reinforced with 2 layers of steel mesh (395), one placed 50mm from the top of the block, the other 50mm from the bottom. Note. The surface of the concrete block must be truly horizontal. 4.4 A surcharge weight attached to the mounting of the vibratory hammer for the purpose of achieving a total suspended mass of 30kg (± 0.5kg) 4.5 Segmented steel split moulds: > 120mm in height and 152mm in diameter for Indirect Tensile Strength (ITS) tests; and > 320mm in height and 150mm diameter for triaxial testing. (The maximum height of moulds for all specimens is 340mm.)

3 3 4.6 A compaction base plate bolted either to the base of the mounting frame or a concrete block at least 300mm thick (as described in 4.3 above). The surface of the base plate must be truly horizontal. 4.7 An interlayer roughening device (IRD) 145mm (± 1mm) in diameter fitted with protruding teeth for roughening the upper horizon of a compacted layer. 4.8 Specimen handling trays (one metal tray per specimen). 4.9 A balance to weigh up to 30kg, accurate to 5g 4.10 Electronic balance (fine measurement type) that complies with SANS 1649 and has the capacity to weigh up to 10kg with an accuracy of 0.1g 4.11 A drying oven, thermostatically controlled and capable of maintaining a temperature of 105 C to 110 C 4.12 Accessories: At least 5 air-tight containers, each with a minimum capacity of 20 litres Vernier calliper capable of measuring up 350mm (±1mm) Mixing basin approximately 500mm in diameter Mixing trowel Material scoop Chisel or spatula approximately 350mm in length Tools (spanners) for assembling / dismantling the split moulds Suitable containers to hold approximately 1 000g of material (for determining the moisture content) Marker pen Stop watch Oil based white paint and a thin artist s paintbrush (for marking the specimens) 5. HAZARDS Prolonged exposure to the noise emitted by a demolition hammer can lead to impaired hearing. The operator should therefore always wear ear plugs and, to protect others in the vicinity, the vibratory hammer compaction unit should be housed in a soundproof cabinet. Working beneath the suspended hammer assembly has the potential of causing bodily harm in the event of the locking device malfunctioning. Such locking device therefore requires regular inspection (and maintenance) to ensure its functionality. In addition, care must be exercised when lowering the tamping foot into the mould to prevent damaging fingers (or hands). 6. PRELIMINATY TESTS AND SAMPLE PREPARATION 6.1 Preliminary tests The Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) of the material must first be established following the SANS 3001 Test Method GR30 (modified AASHTO (T-180)). 6.2 Sample Preparation Material is prepared for moulding at the OMC. Use the formula in Paragraph 8.2 to determine the amount of material to be prepared for manufacturing the number of specimens required for each test. Place the material in a sealed container to prevent moisture loss.

4 4 Note. All specimens are prepared and compacted at a temperature between 20 C and 25 C (both material and air temperature). 7. PROCEDURE FOR MANUFACTURING TEST SPECIMENS 7.1 Preparing the vibratory hammer Ensure that the vibratory hammer frame is securely attached to the concrete support block. Install the hammer into the mounting frame and insert the tamping foot. Using the lifting system, raise and lower the hammer to ensure that there is no resistance to sliding. 7.2 Preparing the mould Clean the mould and base plate. Lubricate the inside of the mould with a light application of lubricating grease or non-stick spray. Fix the mould to the base plate of the compaction frame. Check the alignment of the mould and vibratory hammer by lowering the tamping foot into the mould. Check that the lifting system provides sufficient slack for the tamping foot to rest on the base plate. 7.3 Compacting the material in the mould Number of specimens to be manufactured / number of layers for each specimen. The following table shows the number of specimens required for each test and the number of layers that are compacted sequentially to obtain the required specimen height. Specimens for: ITS test Triaxial test Number of specimens required 6 10 Specimen height (mm) Number of layers Thickness of each layer (mm) may be increased to 3 layers in exceptional circumstances where de-bonding between the 2 layers is experienced 2 if the required density cannot be achieved in any layer after compacting for 120 seconds with the vibratory hammer, the manufacturing procedure should be terminated and the number of layers increased Marking the vertical slide of the frame. Lower the vibratory hammer so that the tamping foot rests on the base plate. Using a marking pen, mark the location of the slide on the frame. Raise the vibratory hammer using the lifting system and secure it at least 500mm above the mould. Using a steel rule, measure upwards from the mark on the frame and accurately mark the distance to the top of the first compacted layer (47.5mm for ITS specimens and 50 mm for triaxial specimens) and subsequent layers (95mm for ITS specimens; 100mm, 150mm, 200mm, 250mm and 300mm for triaxial specimens). Note. Where the vibratory hammer frame is fitted with an electronic system for controlling the compacted thickness of the layers, carefully follow the set up and operating procedures specified by the manufacturer Determine the mass of material required for each layer. Use the formula in Paragraph 8.3 to determine the mass of material required in each layer.

5 Compacting the layers. First layer. Measure out the mass of moist material required for the first layer (accurate to ± 1g) and carefully pour it into the mould without any spillage. Use a chisel to spread the material evenly in the mould avoiding segregation. Retain the remainder of the sample in the sealed container to prevent moisture loss. Lower the vibratory hammer until the tamping foot rests on the material. Ensure that the lifting system is slack, allowing the hammer to slide downwards as the material compacts. Turn on the vibratory hammer and start the stop watch. Allow the hammer to run until the mark on the sliding frame for the first layer comes into view. Immediately turn the hammer off and stop the stop watch. Record the time that the hammer was running (seconds). Raise the vibratory hammer using the lifting system and secure it at least 500mm above the mould. Note. If the compaction time for any layer exceeds 120 seconds, terminate the manufacturing procedure, increase the number of layers and start again. In the unlikely event of the problem persisting with an increased number of layers, terminate the manufacturing procedure and seal all the material in airtight containers. Repeat the moisture / density relationship test on a new sample to determine the correct values for the MDD and OMC. Then start again using the revised MDD as the target density. Prepare the surface of the compacted layer inside the mould using the interlayer roughening device (IRD). Place the IRD on top of the compacted material and apply sufficient pressure so that the teeth fully penetrate into the material. Maintaining the applied pressure, turn the IRD through 90 and then back again at least four (4) times to loosen the material at the top of the layer. Lift the IRD out of the mould and inspect the roughened surface. If the material is not sufficiently loose, repeat the procedure described above as many times as necessary. When the surface has been sufficiently roughened, proceed immediately with the next layer. Second and subsequent layers. Compact the second and subsequent layers following the procedure described above for the first layer. Note. All layers are to be compacted sequentially as a continuous operation. 7.4 Determination of the moisture content After the material for the second layer has been transferred to the mould, place ±1000g of the treated material in a suitable container for determination of the moisture content (following the SANS 3001 Test Method GR20). 7.5 Removing the specimen from the mould After compaction is complete, remove the mould from the base plate, carefully place it on a specimen tray and leave it to stand for a minimum of 4 hours. The two segments of the mould are then carefully dismantled and removed, leaving the specimen on the tray. Specimens are then cured, as described in the relevant Indirect Tensile Strength (ITS) or Triaxial test procedure. 7.6 Marking the specimens For identification purposes, all specimens must be clearly marked with white paint.

6 6 8. CALCULATIONS 8.1 Mass of each specimen at the Optimum Moisture Content (OMC) M S = (π x d 2 )/4 x h x (MDD x (1+ (OMC/100))) where: M S = mass of the specimen at OMC (kg) d = diameter of the specimen (m) h = height of the specimen (m) MDD = maximum dry density of the material being compacted (kg/m 3 ) OMC = optimum moisture content of the material being compacted (%) 8.2 Total mass of treated material required for manufacturing a batch of specimens M B = (N S x M S ) + 5 where: M B = required mass of treated material at the optimum moisture content (kg) N S = number of specimens to be manufactured (see table in Paragraph 7.3.1) M S = mass of each specimen at OMC (kg) 8.3 Mass of material required per layer of equal thickness for specimen manufacture M L = M S / n where: M L = mass of material in each layer (kg) n = number of layers of equal thickness to be compacted 8.4 Moisture content of material (moulding moisture content) W S = (M CM M CD ) / (M CD M C ) x 100 where: W S = moisture content expressed as a percentage of the dry material (%) M CM = mass of container and moist material (g) M CD = mass of container and dry material (g) M C = mass of container only (g) 9 REPORTING Report the following for each specimen: Specimen ID (marking) Date of manufacturing Diameter (mould diameter) Number of layers and compaction time for each layer (to the nearest second) Moulding moisture content (to the nearest 0.1%) This information is to be included with the results of the test carried out on the specimen (ITS or Triaxial).

7 7 ANNEXURE A (informative) EXAMPLES OF THE CALCULATIONS A.1 Determine the mass of each specimen at the Optimum Moisture Content (OMC) Use the equation in Paragraph 8.1: M S = (π x d 2 )/4 x h x (MDD x (1+ (OMC/100))) where: M S = mass of the specimen at OMC (kg) d = diameter of the specimen (m) h = height of the specimen (m) MDD = maximum dry density (kg/m 3 ) OMC = optimum moisture content (%) Example Test ITS Triaxial M S To be calculated d 152mm 150mm h 95mm 300mm MDD 2145kg/m 3 OMC 5.6% Calculation: TEST ITS Triaxial (π x (0.152) 2 )/4) x x (2145 x (1+(5.6/100))) (π x (0.15) 2 )/4) x 0.3 x (2145 x (1+(5.6/100))) M S (kg) x x x 0.3 x = kg = kg A.2 Determine the total mass of treated material required for manufacturing a batch of specimens Use the equation in Paragraph 8.2: M B = (N S x M S ) + 5 where: M B = required mass of treated material at OMC (kg) N S = number of specimens to be manufactured M S = mass of each specimen at OMC (kg). (See A.1) Calculation: TEST ITS Triaxial (6 x 3.906) + 5 (10 x ) + 5 M B (kg) = kg = kg Example ITS Triaxial M B To be calculated N S 6 10 M S A.3 Determine the mass of material required per layer of equal thickness for specimen manufacture Use the equation in Paragraph 8.3: M L = M S / n where: M L = mass of material in each layer (kg) n = number of layers of equal thickness Calculation: TEST ITS Triaxial / / 6 M L (kg) = kg = kg Example ITS Triaxial M L To be calculated M S n 2 6

8 8 A.4 Moisture content of material (moulding moisture content) Use the equation in Paragraph 8.4 W S = (M CM M CD ) / (M CD M C ) x 100 where: W S = moisture content as a percentage of dry material (%) M CM = mass of container and moist material (g) M CD = mass of container and dry material (g) M C = mass of container only (g) Example W S To be calculated M CM 1264 M CD 1216 M C 345 Calculation: W S (%) ( ) / ( ) x / 871 x 100 = 5.5 %

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