What is the minimum compressive strength for these precast blocks?

The average compressive strength must be at least 5.0 N/mm² on the net area (Clause 5.2).

What is the maximum allowed water absorption?

The average water absorption shall not exceed 15 percent by mass (Clause 5.4).

What are the dimensional tolerances for these blocks?

For length and height, the tolerance is ±5 mm. For width, it is ±3 mm (Clause 4.2).

What type of cement should be used for these blocks?

The standard allows for ordinary Portland cement conforming to IS 269 (Clause 3.1).

IS 9893

: 1981

precast concrete blocks for lintels and sills

CurrentSpecializedSpecificationBIMMaterials Science · Cement Matrix Products

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This standard specifies the requirements for materials, dimensions, physical properties, and testing methods for precast concrete blocks. These blocks are intended for use in the construction of lintels and sills in buildings.

precast concrete blocks for lintels and sills

Quick Reference Values

Minimum average compressive strength5.0 N/mm²

Maximum average water absorption15 % by mass

Maximum average block density1900 kg/m³

Dimensional tolerance for length/height± 5 mm

Dimensional tolerance for width± 3 mm

Practical Notes

Ensure blocks are properly cured and dry before installation to achieve specified strength and minimize shrinkage cracks in plaster.

Always check for visible defects like cracks, chips, or broken corners upon delivery to the site, as these can compromise structural integrity and finish.

These blocks are non-loadbearing components used to create the formwork for in-situ lintels/sills; they are not the lintel itself.