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IS 10850:1984 is the Indian Standard (BIS) for apparatus for measurement of water retentivity of masonry cement. This Indian Standard specifies the requirements for the apparatus used to measure the water retentivity of masonry cement. It details the dimensions, materials, and construction of the equipment components, including the perforated test plate, dish, and tamper, to ensure consistency in testing procedures.
Specification for apparatus for measurement of water retentivity of masonry cement
Overview
Status
Current
Usage level
Specialized
Domain
Materials Science — Cement, Concrete, Aggregates and RCC
! This standard only specifies the apparatus; the actual test procedure using this equipment is described in IS 1625 (Specification for masonry cement).
! Ensuring the perforations in the brass plate are clean and not blocked is crucial for accurate test results.
! This apparatus is specific to masonry cement and its ability to retain water, which is a key performance property for mortar and plaster.
Specifies the apparatus for determining water retention of masonry cement mortar within the test methods annex.
EN 413-2:2016CEN (European Committee for Standardization), Europe
HighCurrent
Masonry cement - Part 2: Test methods
Details the test method and apparatus for measuring water retention of masonry cement.
ASTM C1506-20ASTM International, USA
MediumCurrent
Standard Test Method for Water Retention of Hydraulic Cement-Based Mortars and Plasters
Defines the test procedure using an apparatus functionally identical to that in IS 10850.
Key Differences
≠IS 10850 is a standalone standard exclusively for the apparatus, whereas international equivalents like ASTM C91 and EN 413-2 describe the apparatus as part of a broader standard covering test methods or the cement specification itself.
≠IS 10850 explicitly specifies a mercury manometer for vacuum measurement, while modern standards like ASTM C91 and EN 413-2 permit the use of digital vacuum gauges for safety and precision.
≠There is a slight difference in the specified vacuum level: IS 10850 requires 50 mm Hg (~6.7 kPa), ASTM C91 requires 2 in. Hg (~6.8 kPa), and EN 413-2 requires 50 mbar (5.0 kPa).
≠The specification for the filter paper is more detailed in international standards. For example, ASTM C91 specifies a 150 mm diameter paper (e.g., Whatman No. 50), whereas IS 10850 gives a more general description of 'hardened, smooth filter paper' sized to fit the funnel.
Key Similarities
≈All standards are based on the identical fundamental principle of applying a controlled vacuum to a mortar sample on a perforated plate to measure the amount of water extracted.
≈The core components of the apparatus are the same across all standards, consisting of a Buchner-type funnel with a perforated base, a filter flask, a vacuum source, and a pressure measuring device.
≈The general design and approximate dimensions of the funnel, particularly the flat perforated base which defines the test area, are highly consistent to ensure comparable test conditions.
≈All standards require the materials of the apparatus, especially the funnel, to be non-corroding and non-absorbent to prevent reaction with the cementitious mortar.
Parameter Comparison
Parameter
IS Value
International
Source
Applied Vacuum
50 mm of mercury
2 in. [51 mm] of mercury
ASTM C91-23
Applied Vacuum (in SI units)
~6.7 kPa
5.0 kPa (50 mbar)
EN 413-2:2016
Funnel Internal Diameter
100 mm
102 mm (4 in.)
ASTM C91-23
Pressure Measuring Device
Mercury manometer
Vacuum gauge or manometer
ASTM C91-23
Funnel Material
Brass or other suitable non-corrodible material
Non-absorbent, non-corroding, non-reacting material
ASTM C91-23
Filter Paper Diameter
Sized to fit funnel (approx. 110 mm)
150 mm
ASTM C91-23
Apparatus Standard Type
Standalone specification for apparatus only
Apparatus described within a larger test method standard
EN 413-2:2016
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Diameter of perforated brass test plate150 mm
Thickness of test plate1.6 mm
Number of holes in test plate49
Diameter of holes in test plate1.6 mm
Depth of the retaining dish25 mm
Mass of the tamper1 kg
Tables & Referenced Sections
Key Tables
No tables data
Key Clauses
Clause 2 - Apparatus
Clause 3 - Test Plate and Dish
Clause 5 - Tamper
Clause 7 - Balance
Frequently Asked Questions4
What is the primary purpose of IS 10850?+
To define the standard specifications for the apparatus used in determining the water retentivity of masonry cement, ensuring uniform and repeatable testing.
What are the specified dimensions for the perforated test plate?+
It must be a 150 mm diameter, 1.6 mm thick brass plate with 49 holes of 1.6 mm diameter, as per Clause 3.1.
What is the required mass of the tamper used in the test?+
The tamper shall have a mass of 1 kg, according to Clause 5.1.
Which code describes the actual test method for water retentivity?+
The test procedure that uses the apparatus specified in this standard is detailed in IS 1625.