Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 3951:2000 (Part 1) is the Indian Standard (BIS) for hollow clay tiles for floors and roofs, part 1: filler type -. This standard specifies the dimensions, physical requirements, and testing methods for hollow clay tiles used as filler blocks in concrete floors and roofs. It ensures the tiles possess adequate compressive strength and acceptable water absorption to safely reduce the dead weight of ribbed concrete slabs without compromising structural integrity.
Hollow clay tiles for floors and roofs, Part 1: Filler type -
Overview
Status
Current
Usage level
Specialized
Domain
Materials Science — Clay and Stabilized Soil Products
EN 15037-3:2011CEN, European Committee for Standardization
HighCurrent
Precast concrete products — Beam-and-block floor systems — Part 3: Clay blocks
Both standards specify requirements for clay blocks used as fillers in floor and roof systems.
ASTM C56 / C56M - 11(2021)ASTM International, USA
MediumCurrent
Standard Specification for Structural Clay Nonloadbearing Tile
Covers non-loadbearing clay tiles, a similar functional category, but not specifically for floor filler systems.
AS/NZS 4455.3:2008Standards Australia / Standards New Zealand
LowCurrent
Masonry units, pavers, flags and segmental retaining wall units - Masonry units
A general standard for masonry units; clay blocks for floors would be a subset but are not specifically addressed.
Key Differences
≠IS 3951 uses a rigid classification system based on average compressive strength (Class 5 and Class 3.5), whereas EN 15037-3 requires the manufacturer to declare a characteristic strength value without predefined classes.
≠IS 3951 mandates a maximum average water absorption of 20% by mass. In contrast, EN 15037-3 does not set a mandatory limit, treating it as a performance characteristic to be declared by the manufacturer if relevant.
≠The Indian standard specifies a test for efflorescence, which is a common concern in tropical climates. The European standard EN 15037-3 does not address efflorescence but includes provisions for freeze-thaw resistance, which is critical in colder European climates.
≠Dimensional tolerances in IS 3951 are expressed as simple percentages (e.g., ±3% on height). EN 15037-3 provides a more detailed system of tolerance classes (e.g., T1, T2) which can combine absolute values (mm) and percentages.
Key Similarities
≈Both IS 3951 and EN 15037-3 are specifically for burnt clay (ceramic) units designed for use in floor and roof construction.
≈The fundamental purpose defined in both standards is for the blocks to act as non-structural or semi-structural fillers between load-bearing beams (typically concrete) to form a slab.
≈Both standards require compressive strength to be tested on the net area of the block, in the same direction it would be loaded within the final floor assembly.
≈All compared standards (IS, EN, ASTM) recognize the importance of controlling the overall dimensions (length, width, height) of the blocks to ensure proper fit and integrity of the floor system.
Parameter Comparison
Parameter
IS Value
International
Source
Compressive Strength Classification
Two classes: ≥ 5.0 N/mm² and ≥ 3.5 N/mm² (average strength).
No predefined classes; manufacturer declares a characteristic strength value.
EN 15037-3:2011
Water Absorption (Max Average)
≤ 20% (by mass, 24-hour cold soak)
≤ 25% (by mass, 1-hour boiling test)
ASTM C56 / C56M - 11(2021)
Water Absorption Requirement
Mandatory limit of ≤ 20%.
No limit prescribed; value is to be declared by the manufacturer.
EN 15037-3:2011
Dimensional Tolerance (on Height)
± 3% of the specified height.
Tolerance Class T1: ± 3 mm or ±3%, whichever is greater.
EN 15037-3:2011
Minimum Compressive Strength
Class 3.5 requires ≥ 3.5 N/mm² (or 3.5 MPa).
Grade NB (side construction) requires ≥ 4.8 MPa (average strength).
ASTM C56 / C56M - 11(2021)
Efflorescence Test
Required, with results classified as Nil, Slight, Moderate, or Heavy.
Not specified as a requirement.
EN 15037-3:2011
Freeze-Thaw Resistance
Not specified.
Required if blocks are used in freeze-thaw conditions; test methods are defined.
EN 15037-3:2011
⚠ Verify details from original standards before use
What is the difference between Part 1 and Part 2 of IS 3951?+
Part 1 covers filler type (non-structural) tiles used merely to fill voids, while Part 2 covers structural type tiles designed to bear and transfer structural loads.
What is the maximum allowed water absorption for these tiles?+
The maximum water absorption is generally restricted to 20% by mass to ensure durability.
Which standard specifies the testing methods for these structural tiles?+
Tests for compressive strength, water absorption, and efflorescence are typically conducted in accordance with IS 3495 (Parts 1 to 4).