What is the maximum allowed water absorption for a clay jalli?

20% by mass after 24-hour immersion in cold water (Table 2).

What is the minimum compressive strength for a standard clay jalli?

The average compressive strength on the net area of the web shall not be less than 3.5 N/mm² for Type A and B jallies (Table 2).

What are the main types of jallies as per IS 7556?

Type A (thickness ≥ 40 mm), Type B (thickness < 40 mm), and Type C (hand-moulded jallies of non-modular sizes) (Clause 3).

What is the dimensional tolerance for a 200mm x 200mm jalli?

The length and width can vary by ± 3 mm (Clause 4.2).

IS 7556

: 1988

burnt clay jellies

CurrentSpecializedSpecificationBIMArchitectural · Clay and Stabilized Soil Products

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This standard specifies the requirements for burnt clay jallies, which are perforated screens used for ventilation, privacy, and architectural purposes. It covers material, dimensions, tolerances, physical characteristics like compressive strength and water absorption, and methods of sampling and testing. The standard ensures a minimum level of quality for jallies used in building construction.

burnt clay jellies

Quick Reference Values

Maximum water absorption (24-hr immersion)20% by mass

Minimum average compressive strength (on net area)3.5 N/mm²

Tolerance on length and width± 3 mm

Tolerance on thickness± 2 mm

Minimum thickness of Type A jalli40 mm

Practical Notes

Burnt clay jallies are typically non-load-bearing elements and are used for creating decorative screens or ventilation openings.

Always check for visual defects like cracks, warpage, and efflorescence as per Clause 5 before acceptance and installation.

The compressive strength is tested on the individual 'webs' or solid portions of the jalli, not the unit as a whole.