M. K. Instruments

Khokhra, ahmedabad, Gujarat

IS: 516, IS: 9399, BS: 1881, and ASTM C78The Flexure Strength Testing Machines are designed to provide maximum rigidity throughout their working range. The downward movement of Hydraulic ram applies the load. The jack can be raised or lowered for testing different size beams. The load is indicated on a calibrated Bourdon tube type load gauge of range: 0-100KN X 0.5KN (0-10, 000 kgf X 50 kgf). The load gauge is calibrated against NPL/NCCBM certified proving ring.

The concrete is a man-made material, essential mixed at site. The properties of concrete depend on the properties of its ingredients and their proportion, and it is likely to vary from mix to mix. Tests must be conducted, therefore, to ensure that theconcrete used is in accordance with design specifications. It is a frequent test of compressive strength, in which concretesamples are tested to failure.

For Compression test on Concrete or Similar materials, suitable for use on Concrete cubes of any size upto 5cm x 5cm x 5cm, 7.06 x 7.06cm, 10cm x 10cm x 10cm, and 15cm x 15cm x 15cm also on 10 x 20cm and 15 x 30cm high concrete cylinders. Theload is applied through hydraulic assembly.

The lower platen is on the Hydraulic Ram, and upper having a spherical seating is adjustable. The machine is provided with anair release valve and the load is automatically indicated on the 15cms dia hydraulic pressure calibrated against an N.C.B.M. tested Proving Ring and fitted with a legless max pointer in addition to the live pointer.

Features:

• High stability,
• Self-aligning platen assembly,
• Gauges are calibrated in kN against certified proving rings
• Suitable for testing cubes and cylinders of various sizes
• Using special platens, bricks can also be tested
• Hardened and grinded platens with guide lines for placing sample for testing.

1. Compression Testing Machine, Hand Operated 25, 000 kgf (250 kN- Channel Model) double plunger pump with hydraulic pressure gauge with our own Calibration Report.
2. Compression Testing Machine, Hand Operated 50, 000 kgf (500 kN- Channel Model) double plunger pump with hydraulic pressure gauge with our own Calibration Report.
3. Compression Testing Machine, Hand Operated 100, 000 kgf (1000 kN- Channel Model) double plunger pump with hydraulic pressure gauge with our own Calibration Report.
4. Compression Testing Machine, Hand Operated 100, 000 kgf (1000 kN- Pillar Model) double plunger pump with hydraulic pressure gauge with our own Calibration Report.
5. Compression Testing Machine, Hand Operated 200, 000 kgf (2000 kN Channel Model) double plunger pump with hydraulic pressure gauge with our own Calibration Report.

The machine is used for testing crushed slag, crushed and uncrushed gravel for resistance to abrasion. The aim of the test is to find the percentage wear due to the relative rubbing action between the aggregates and steel balls used as abrasive charge. The oven dried aggregates are weighed and rotated along with abrasive charge in the machine for the 500 or 1000 revolutions and percentage of wear so found out is reported as Los Angeles abrasion value.

The machine consists of a hollow cylinder mounted horizontally on a sturdy frame on ball bearings. There is an opening which can be closed with adjust tight cover to facilitate charging and discharging the drum with the material under test. A detachable shelf which extends throughout the inside length of the drum which catches the abrasive charge and does not allow it to fall on the cover. The drum is rotated by an electric motor through a heavy reduction gear at a speed of 30-33 R.P.M. A revolution counter is fitted to the frame. A tray is supplied for collection of the material at the end of the test. Complete with abrasive charge consisting of a set of twelve hardened steel balls, approximately 48mm dia, suitable for operation on 440V, 3 phase, 50 cycles, A.C. Supply.

The test is applicable to hot mix designs using bitumen and aggregates upto a maximum size of 25mm. In this method, the resistance to plastic deformation of cylindrical specimen of bitumenous 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 programmes for paving jobs. There are two major features of the Marshall method of designing mixes namely, a) Density voids analysis b) 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 60C. The flow value is deformation the marshall test specimen under goes during the loading upto the maximum load, 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 :

• A loading unit motorized, capacity 5000kgf 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 manually move the pillars is on the right. The load frame has fixed speed of 5.08cm per minute. Operated on 230 Volts A.C
• 1 No. Compaction pedal with specimen mould holder
• 2 Nos. Compaction Rammers, 4.5kg weight and free fall 45.7cm.
• 1 No. Breaking head assembly with provision to fix flowmeter
• 3 Nos. Specimen mould 10.16cm I.D. x 7.6cm high with base plate and extension collar.
• 1 No. Kit for specimen extraction, consists of one each load transfer bar, steel ball, specimen extracting plate.

Bituminous surfaces exposed to varying temperature conditions undergo a great deal of expansion and contraction. Therefore, an important characteristic of the binder is its ductility and the degree of ductility has an effect on the cracking of bituminous surfaces caused by traffic stress. The ductility of bitumen is expressed as the distance in centimetres to which a standard briquette can be elongated before the thread thus formed breaks under specified conditions.

A molten bitumen sample is poured into a standard mould, allowed to cool to room temperature and then placed in a water bath so that the briquette can be brought to test temperature before mounting in the testing machine.

Designed to test three specimens simultaneously. The machine consists of a carriage moving over a lead screw. An electric motor driven reduction gear unit ensures smooth constant speed and continuous operation. The entire assembly is mounted with a stainless steel lined water bath completely encased in metal bound hardwood. It is equipped with an electric pump circulator and heater. The temperature is controlled thermostatically. Two rates of travel i.e. 5 cm/min and 1 cm/min are provided. Suitable for operation on 230 V, 50 Hz, Single Phase, A.C. supply.

The Aggregate impact value of coarse aggregate provides a relative measure of the resistance of an aggregate to sudden shock or impact. The oven dried and accuracy weighed aggregates are subjected to a total of 15 blows of specified weight and fall and percentage of fines formed in terms of the total weight of the sample is expressed as the aggregate impact value.

The Apparatus consists of following:-

• A Testing Machine having a metal base with a painted lower surface of not less than 30cm in diameter. It is supported on level and plane concrete floor of minimum 45cm thickness. The machine have provisions for fixing its base.
• A Cylinderical cup of internal diameter of 102mm, depth 50mm and minimum thickness 6.3mm.
• A metal hammer or tup weighing 13.5 to 14 kg the lower end being cylindrical in shape, 50mm long, 100.0mm in diameter with a 2mm chamfer at the lower edge and case hardened. The hammer will slide freely between vertical guides and be concentric with the cup. Free fall of hammer will be within 380 + 5 mm
• A Cylinderical metal measure having internal diameter 75mm and depth 50mm for measuring aggregates.
• Tamping Rod 10mm in diameter and 230mm long, rounded at one end.