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IS 8870:1978 is the Indian Standard (BIS) for asbestos cement cable conduits and troughs. This standard specifies the requirements for materials, dimensions, manufacturing, and testing of asbestos cement conduits, troughs, and associated fittings. These products were intended for the protection of electrical power and communication cables laid underground or on surfaces.
Consolidated list per BIS. For the text of each amendment, refer to the BIS portal link above.
asbestoscementasbestos cement
International Equivalents
Similar International Standards
ASTM C875-92ASTM International, USA
HighWithdrawn
Standard Specification for Asbestos-Cement Conduit
Direct equivalent covering asbestos-cement conduits for electrical cable protection.
IEC 61386-24:2019International Electrotechnical Commission (IEC), International
LowCurrent
Conduit systems for cable management - Part 24: Particular requirements - Conduit systems buried underground
Covers the functional requirement (underground cable protection), but for modern materials (e.g., plastics, metals), not asbestos-cement.
BS 746:1991British Standards Institution (BSI), UK
MediumWithdrawn
Specification for asbestos cement pipes, joints and fittings for sewerage and drainage
Covered the same material (asbestos-cement) but for a different application (sewerage), sharing many material and testing principles.
ISO 9933:1991International Organization for Standardization (ISO), International
HighWithdrawn
Products in fibre-reinforced cement — Asbestos-cement conduits, joints and fittings for electrical installations
Direct ISO equivalent for asbestos-cement electrical conduits, very similar in scope to IS 8870.
Key Differences
≠The primary material in IS 8870 is asbestos fibre mixed with cement. Modern international equivalents like IEC 61386 explicitly prohibit asbestos and are designed for materials like PVC, HDPE, or steel.
≠IS 8870 specifies fixed minimum performance values (e.g., a single crushing load). Modern standards like IEC 61386 use a performance classification system (e.g., codes for light, medium, heavy duty) allowing users to select a product appropriate for the specific application.
≠Historical standards like IS 8870 and ASTM C875 lack the rigorous environmental, health, and safety (EHS) considerations and markings (e.g., RoHS, REACH) that are integral to current international standards for construction products.
≠IS 8870 covers both circular conduits and semi-circular/U-shaped troughs. Many international standards for conduits focus exclusively on circular or oval cross-sections.
Key Similarities
≈The fundamental purpose defined in all standards is the mechanical protection of electrical and communication cables from external damage and environmental factors.
≈Both IS 8870 and its historical/modern counterparts include a test for resistance to lateral crushing forces (termed 'Transverse Crushing Test' in IS 8870 and 'Compression Resistance Test' in IEC 61386).
≈All standards emphasize dimensional control, specifying nominal diameters, standard lengths, and tolerances for straightness to ensure compatibility and proper installation.
≈Tests to determine resistance to water ingress or absorption are a common feature, as this is a critical performance attribute for products often buried underground.
Parameter Comparison
Parameter
IS Value
International
Source
Primary Material
Portland cement and asbestos fibre
Asbestos-cement (explicitly defined)
ASTM C875-92
Primary Material (Modern)
Portland cement and asbestos fibre
Material-dependent (e.g., PVC-U, Polypropylene, Steel, Aluminium). Asbestos is prohibited.
IEC 61386-24:2019
Transverse Crushing Strength (100 mm dia)
Minimum 4000 N/m
Minimum 11,700 N/m (800 lbf/ft) for Type II (direct burial)
ASTM C875-92
Water Absorption Test
Maximum 30% increase in mass after 24h immersion
Water absorption test is specified, but typically with lower limits in ASTM standards for pressure pipes (often <10%). Specific C875 value is not readily available.
ASTM C875-92
Standard Length
3 metres
Up to 13 ft (approx. 3.96 m)
ASTM C875-92
Straightness Tolerance
Deviation not to exceed 6 mm/m length
Deviation not to exceed 0.25 in./ft (approx. 20.8 mm/m)
ASTM C875-92
Hydrostatic Test Pressure
0.7 N/mm² (for 2 minutes)
250 psi (approx. 1.72 N/mm²) for 5 seconds
ASTM C875-92
⚠ Verify details from original standards before use
Key Values4
Quick Reference Values
Maximum water absorption (average)28% by mass
Minimum transverse crushing load (100 mm conduit)2.0 kN/m
Minimum hydraulic test pressure0.1 N/mm² for 2 minutes
Maximum deviation on straightness per metre length3 mm