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For field work, our engineers and instruments mobilise anywhere in India — highway corridors, bridges, plants and greenfield alignments included.
Paving-grade bitumen testing to IS 73 and IS 1201–1220 — penetration, softening point, ductility, flash point and viscosity for road contractors and hot mix plants
Bitumen is tested to the IS 1201–1220 series — including penetration (IS 1203), softening point (IS 1205), ductility (IS 1208), viscosity (IS 1206) and flash & fire point (IS 1209) — and graded against the specification in IS 73. NKMPV performs the full bitumen test suite as a NABL-accredited laboratory.
Bitumen testing determines the physical and rheological properties of paving-grade bitumen used in road construction, including penetration, softening point, ductility, viscosity, and flash point. These tests verify that the bitumen grade conforms to IS 73 specifications before it is used in hot mix asphalt production.
The following parameters are evaluated during bitumen testing. Acceptance criteria shown are for VG-30 grade paving bitumen as per IS 73:2013, which is the most commonly specified grade for highway construction in North India.
| Parameter | Value / Range | Unit | Standard |
|---|---|---|---|
| Penetration at 25°C | 50-70 dmm (VG-30) | 0.1 mm (dmm) | IS 1203 |
| Softening Point (Ring & Ball) | ≥ 47°C (VG-30) | °C | IS 1205 |
| Ductility at 25°C | ≥ 40 cm (VG-30) | cm | IS 1208 |
| Specific Gravity at 27°C | 0.97-1.02 (typical for paving bitumen) | IS 1202 | |
| Flash Point (Cleveland Open Cup) | ≥ 220°C | °C | IS 1209 |
| Absolute Viscosity at 60°C | 2400-3600 Poise (VG-30) | Poise | IS 73:2013 Table 1 |
| Kinematic Viscosity at 135°C | ≥ 350 cSt (VG-30) | cSt | IS 73:2013 Table 1 |
| Saybolt Furol Viscosity (cutbacks & emulsions) | Flow time in seconds; limits per the product grade | s | IS 1206 |
| Solubility in Trichloroethylene | ≥ 99% | % | IS 1216 |
Paving Bitumen — Specification (Viscosity Grade)
Methods for Testing Tar and Bituminous Materials — Determination of Penetration
Methods for Testing Tar and Bituminous Materials — Determination of Softening Point (Ring and Ball Apparatus)
Methods for Testing Tar and Bituminous Materials — Determination of Ductility
Methods for Testing Tar and Bituminous Materials — Determination of Specific Gravity
Methods for Testing Tar and Bituminous Materials — Determination of Flash Point and Fire Point (Cleveland Open Cup Method)
Specifications for Road and Bridge Works — Section 500 (Bituminous Courses)
AIMIL AIM-501
Automatic needle release with 100 g standard load, 0.1 mm dial gauge, thermostatically controlled water bath at 25°C
CalibratedEIE Instruments (IS pattern)
Dual-ring setup with steel ball guides, glycerin/water bath for softening point up to 80°C, thermometer range 0-100°C (least count 0.2°C)
CalibratedAIMIL AIM-503
Pull speed 50 mm/min ± 2.5%, water bath maintained at 25 ± 0.5°C, travel length up to 1000 mm
CalibratedHumboldt H-3200
Gas burner with adjustable flame, temperature range up to 400°C, ASTM thermometer
CalibratedCannon-Manning vacuum capillary viscometer
Temperature-controlled oil bath at 60 ± 0.1°C, vacuum regulated to 300 mm Hg, suitable for VG-10 to VG-40 range
CalibratedStandard 50 ml borosilicate glass pycnometer
Water bath maintained at 27 ± 0.1°C as per IS 1202, analytical balance (0.001 g accuracy)
CalibratedA representative bitumen sample of approximately 2-3 kg is collected from the storage tank, drum, or hot mix plant as per IS 1195 guidelines. Bulk samples are drawn from three levels (top, middle, bottom) of the drum to detect any settling or contamination. The sealed container is brought to the laboratory and the bitumen is heated uniformly to a pouring temperature (not exceeding 170°C to prevent hardening) for preparing test specimens.
The bitumen sample is melted, poured into a standard penetration cup, and allowed to cool to room temperature. The cup is then placed in a water bath maintained at 25 ± 0.1°C for 1.5 hours. The cup is transferred to the penetrometer platform, and a standard needle (100 g total load) is brought to the bitumen surface. The needle is released for exactly 5 seconds, and the penetration depth is recorded in units of 0.1 mm. Three readings are taken and averaged; they must not differ by more than 4 dmm.
Two brass rings are filled with molten bitumen and levelled after cooling. A steel ball (3.5 g) is placed on each ring inside the Ring and Ball apparatus. The assembly is suspended in a beaker of freshly boiled distilled water (for softening points below 80°C) and heated at a uniform rate of 5°C per minute. The softening point is recorded as the temperature at which the bitumen, pushed down by the steel ball, touches the bottom plate 25 mm below the ring. The average of both rings is reported; the two readings must agree within 1°C.
Bitumen is poured into standard briquette moulds to form dog-bone shaped specimens. After cooling, the moulds are trimmed and placed in the ductility machine water bath at 25 ± 0.5°C for 90 minutes. The specimen clips are then attached to the machine, and the bitumen is pulled apart at a constant rate of 50 mm/min. The ductility value is the distance in centimetres at which the bitumen thread breaks. For VG-30 grade, the minimum ductility must be 40 cm.
Flash point is determined using the Cleveland Open Cup method — bitumen is heated in a brass cup at a prescribed rate while a test flame is passed over the surface at regular intervals until a flash is observed. Specific gravity is measured using a pycnometer at 27°C per IS 1202. Absolute viscosity at 60°C is measured using a vacuum capillary viscometer in an oil bath, with the flow time converted to Poise using the viscometer calibration constant. These tests confirm the viscosity grade classification.
All results are compiled into an NABL-accredited test certificate listing penetration value, softening point, ductility, specific gravity, flash point, and viscosity. The report identifies the viscosity grade of the tested bitumen per IS 73:2013 and provides a compliance assessment against the specified grade requirements. Results are cross-referenced with MoRTH Section 500 acceptance limits where applicable. Digital reports are dispatched within 2-3 working days of sample receipt.
Our bitumen test certificates carry NABL accreditation under ISO/IEC 17025:2017, ensuring they are accepted by NHAI, state PWDs, DGCA, municipal corporations, and arbitration tribunals for all compliance and contractual purposes.
We perform penetration, softening point, ductility, flash point, specific gravity, and viscosity in a single engagement — providing the full IS 73 characterisation needed for grade verification and mix design inputs.
Our water baths and oil baths maintain temperatures to ± 0.1°C accuracy, which is critical for bitumen tests where a 1°C deviation can shift penetration values by 2-3 dmm. All temperature sensors are NABL-calibrated.
Unlike cement or concrete testing that requires multi-week curing periods, bitumen tests are completed within 2-3 working days. For urgent highway projects, we offer same-day preliminary results for penetration and softening point.
Our team understands MoRTH specifications, NHAI quality protocols, and state PWD acceptance norms for bituminous materials. We test VG-10, VG-30, VG-40, modified bitumen (PMB/CRMB), and bitumen emulsions used across North India.
Bitumen quality is determined by viscosity grading per IS 73:2018, which classifies bitumen into four grades: VG-10, VG-20, VG-30, VG-40 based on absolute viscosity at 60°C. Each grade has specified ranges for: penetration (IS 1203, 0.1 mm units at 25°C), softening point (IS 1205, ring-and-ball method), ductility (IS 1208, cm at 25°C), flash and fire point (IS 1209), specific gravity (IS 1202), solubility in trichloroethylene (IS 1216, min 99%), and thin-film oven test mass loss (IS 1218, max 0.8%). MoRTH typically specifies VG-30 for moderate climate and VG-40 for high-traffic / warmer regions. NABL-accredited test reports establish bitumen quality for project acceptance.
The IS 1203 penetration test measures the consistency of bitumen by determining the distance in 0.1 mm units that a standard needle (100 g load, 5 seconds, 25°C) penetrates into a bitumen sample. Higher penetration = softer bitumen; lower penetration = harder bitumen. The result indicates the bitumen's stiffness at service temperature and is one input to viscosity-grade classification under IS 73. Typical values: VG-10: 80–100, VG-20: 60–80, VG-30: 50–70, VG-40: 40–60. The test requires a calibrated penetrometer, water bath at 25°C ± 0.1°C, and the standard cylindrical needle. NKMPV performs penetration testing as part of every bitumen acceptance suite per IS 1203 and the parent IS 73 grading.
Yes. Our laboratory runs a Saybolt Furol viscometer, which measures viscosity as the time in seconds that a fixed volume of binder takes to flow through the standard Furol orifice at a controlled temperature (IS 1206). It is the practical viscosity check for cutback bitumen and bitumen emulsions, where the grade specification sets the acceptable range.
Coverage
Wherever your project is, there are two ways to work with NKMPV on Bitumen Testing.
For field work, our engineers and instruments mobilise anywhere in India — highway corridors, bridges, plants and greenfield alignments included.
Distance is not a constraint for laboratory testing. Send samples to our Pinjore laboratory and receive the digital report on completion — the route most of our out-of-region clients use.
These are locations where we have completed projects — not the boundary of our service area. We mobilise across India on request. See full coverage & project locations →
Bitumen Testing is carried out to IS 73:2013, IS 1203:1978, IS 1205:1978 and IS 1208:1978, as listed in the Applicable Standards section of this page. Tell us the specification your project must comply with and the quotation will state the standard the work follows.
Our laboratory is at Pinjore, Haryana, within same-day reach of Chandigarh, Panchkula, Mohali, Ambala and the wider Tri-City. If you are further away, distance is not a constraint: our field team travels to site anywhere in India for on-site work, and for laboratory tests you can courier samples to the Pinjore lab and receive the report digitally. Clients across Punjab, Haryana, Himachal Pradesh, Delhi-NCR, Uttarakhand, Rajasthan, Uttar Pradesh, Jammu and Kashmir and Ladakh already work with us this way.
Yes. NKMPV operates pan-India. We have delivered projects across Chandigarh, Panchkula, Mohali, Ambala, Karnal, Kurukshetra, Yamunanagar, Hisar and beyond, and we mobilise to greenfield and remote corridors on request. The 18 locations listed on our site are the places we have already worked — not the limit of where we go.
Send us the project details — location, quantity, and the standard you need to comply with — and you get a written quotation, usually within one working day. Pricing depends on sample count, site access and mobilisation distance, so we quote per project rather than publishing a fixed rate. Call +91-82953-60108 or use the quote form; every quotation states the applicable IS/IRC standard.
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