What is the minimum compressive strength for lime-based blocks?

The minimum average 28-day compressive strength should be 3.5 N/mm² (Table 1).

What materials are used to make these blocks?

The primary materials are building lime (conforming to IS 712) and aggregates such as cinder, granulated slag, or other suitable materials (Clause 3).

What is the maximum allowed water absorption?

The maximum water absorption after 24 hours of immersion is 20 percent by mass (Table 1).

What is the maximum allowed drying shrinkage?

The maximum drying shrinkage is specified as 0.15 percent (Table 1).

IS 10049

: 1981

Code of practice for the manufacture of lime-based blocks

CurrentSpecializedCode of PracticeMaterials Science · Building Limes and Gypsum Products

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This standard outlines the procedures for manufacturing lime-based building blocks, suitable for masonry. It specifies the requirements for raw materials like lime and aggregates, details the mixing, moulding, and curing processes, and sets the minimum physical properties such as compressive strength, density, and drying shrinkage for the finished blocks.

Code of practice for the manufacture of lime-based blocks

Quick Reference Values

Minimum average compressive strength (28 days)3.5 N/mm²

Minimum compressive strength of individual unit (28 days)2.8 N/mm²

Maximum block density1800 kg/m³

Maximum drying shrinkage0.15 %

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

Practical Notes

Curing is a critical step; unlike cement, lime gains strength slowly through carbonation, requiring a controlled environment.

The quality of lime (as per IS 712) and aggregate has a direct and significant impact on the final block's performance.

These blocks are generally suitable for non-load-bearing or partition walls due to their moderate strength characteristics compared to concrete blocks.