IS 11650 : 1991Guide for the manufacture of standard burnt clay building bricks by semi-mechanized process

Q: What is the main advantage of the semi-mechanized process over hand-moulding?

It produces more uniform, denser, and stronger bricks due to better clay preparation in a pug mill and consistent moulding through a machine (Clause 5 & 6).

Q: What type of soil is considered good for brick making according to this guide?

Silty clay or sandy clay with a plasticity index between 15 and 25, and low soluble salt content (<1%) is generally suitable (Clause 4.1).

Q: What kind of kiln is typically used in this process?

The guide suggests continuous kilns like the Bull's Trench Kiln (BTK) or Hoffmann Kiln are suitable for the scale of semi-mechanized production (Clause 8.1).

Q: How does this code relate to IS 1077 and IS 3495?

IS 11650 provides the 'how-to' for manufacturing bricks, while IS 1077 specifies the required final dimensions and quality of the bricks, and IS 3495 describes the methods to test if those quality requirements are met.

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EN 771-1 · ASTM C62 · AS/NZS 4455.1

CurrentSpecializedGuidelinesMaterials Science · Clay and Stabilized Soil Products

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IS 11650:1991 is the Indian Standard (BIS) for guide for the manufacture of standard burnt clay building bricks by semi-mechanized process. This standard provides guidance on the manufacturing process of burnt clay building bricks using semi-mechanized methods. It covers all stages from site selection and raw material (clay) evaluation to clay preparation, moulding, drying, firing in kilns, and final handling. The guide aims to help manufacturers produce bricks that conform to the quality specifications laid out in IS 1077.

Guide for the manufacture of standard burnt clay building bricks by semi-mechanized process

Overview

Status: Current
Usage level: Specialized
Domain: Materials Science — Clay and Stabilized Soil Products
Type: Guidelines

International equivalents

EN 771-1:2011+A1:2015 · CEN (European Committee for Standardization), Europe ASTM C62-17 · ASTM International, USA AS/NZS 4455.1:2008 · Standards Australia/Standards New Zealand, Australia/New Zealand

Typically used with

IS 1077 IS 2117 IS 2248 IS 2720

Also on InfraLens for IS 11650

6Key values 2Tables 4FAQs

Practical Notes

! Ensure the clay is free from 'kankar' (calcareous nodules), as they can cause bricks to spall or burst upon wetting after firing.

! The semi-mechanized process, particularly the use of a pug mill and extruder, yields bricks with higher density and uniformity compared to the hand-moulding process described in IS 2117.

! Careful control of the firing schedule (temperature and atmosphere) in the kiln is critical to prevent defects like black cores, brittleness, or bloating.

Frequently referenced clauses

Cl. 4Raw Materials Cl. 5Preparation of Brick Earth Cl. 6Moulding Cl. 7Drying Cl. 8Burning Cl. 9Sorting, Stacking and Transport

claysoilbricks

International Equivalents

Similar International Standards

EN 771-1:2011+A1:2015CEN (European Committee for Standardization), Europe

LowCurrent

Specification for masonry units - Part 1: Clay masonry units

Specifies the performance characteristics of the final clay brick, which is the goal of the IS 11650 manufacturing guide.

ASTM C62-17ASTM International, USA

LowCurrent

Standard Specification for Building Brick (Solid Masonry Units Made From Clay or Shale)

Defines the grading and properties of finished building bricks, not the manufacturing process itself.

BS 3921:1985BSI (British Standards Institution), UK

LowWithdrawn

Specification for Clay Bricks

Formerly specified requirements for clay bricks in the UK, focusing on the final product rather than the manufacturing method.

AS/NZS 4455.1:2008Standards Australia/Standards New Zealand, Australia/New Zealand

LowCurrent

Masonry units, pavers, flags and segmental retaining wall units, Part 1: Masonry units

Sets performance requirements for finished masonry units, leaving manufacturing details to the producer.

Key Differences

≠IS 11650 is a prescriptive process guide detailing 'how' to manufacture bricks (raw material prep, moulding, drying, firing), whereas international standards like ASTM C62 are performance specifications defining 'what' properties the final product must have.

≠The Indian standard provides specific guidance on raw material (soil) composition, such as recommended sand and clay content, and field tests for suitability. International standards do not prescribe raw material composition.

≠IS 11650 details specific process parameters like pugging methods, drying schedules, and typical firing temperatures and kiln types (e.g., Bull's Trench Kiln), which are not specified in international performance-based standards.

≠The 'semi-mechanized' scope of IS 11650 is unique, addressing a specific level of industrialization common in the region, whereas international standards are written to be applicable to any manufacturing scale, from fully automated to semi-mechanized.

Key Similarities

≈The fundamental objective is the same across all standards: to produce sound, durable, and regularly shaped burnt clay bricks suitable for building construction.

≈All standards are based on the use of clay and/or shale as the primary raw material for brick production.

≈The implied manufacturing sequence of raw material preparation, shaping, drying, and firing is common, even though only IS 11650 explicitly details the steps.

≈All standards recognize proper firing (vitrification) as the critical step for achieving key properties like compressive strength, durability, and low water absorption.

Parameter Comparison

Parameter	IS Value	International	Source
Water Absorption (Target)	Aims for < 20% by weight (24-hr cold immersion) for a well-burnt brick.	Grade SW: ≤ 17.0% (avg); Grade MW: ≤ 22.0% (avg) for 5-hr boil test.	ASTM C62-17
Compressive Strength (Target)	Process aims to meet classes in IS 1077, starting from 3.5 N/mm² (MPa).	Grade SW: ≥ 20.7 N/mm² (3000 psi) avg; Grade MW: ≥ 17.2 N/mm² (2500 psi) avg.	ASTM C62-17
Raw Material - Sand Content	Recommends soil with 20-30% sand.	Not specified; performance-based, allowing any suitable composition.	EN 771-1 / ASTM C62
Process Control - Drying Shrinkage	Linear drying shrinkage of prepared clay should be less than 7%.	Not specified for the final product; considered an internal process control parameter for the manufacturer.	EN 771-1
Process Control - Firing Temperature	Suggests a firing range of 900–1100 °C.	Not specified; left to manufacturer to determine optimal firing for their materials to meet performance requirements.	ASTM C62-17
Efflorescence	Aims for 'Slight' or 'Nil' rating when tested as per IS 3495 (Part 3).	Qualitative requirement to be 'not effloresced' when tested as per ASTM C67.	ASTM C62-17
Dimensional Tolerances	The process guide aims to produce bricks meeting tolerances in IS 1077 (e.g., Length ±3mm, Width ±1.5mm for modular bricks).	Specifies tolerance categories (e.g., T1, T2, Tm) based on mean dimension vs. work dimension.	EN 771-1

⚠ Verify details from original standards before use

Key Values6

Quick Reference Values

Recommended plasticity index for brick clay15 - 25

Recommended liquid limit for brick clay30 - 45 percent

Maximum allowable soluble salts in clay< 1 percent

Water required for pugging (tempering)12 - 18 % by weight of clay

Typical firing temperature range900 - 1100 °C

Maximum linear drying shrinkage7 - 10 %

Tables & Referenced Sections

Key Tables

Table 1 - Guide for Selection of Site for a Brick Plant

Table 2 - Classification of Brick Earth

Key Clauses

Clause 4 - Raw Materials

Clause 5 - Preparation of Brick Earth

Clause 6 - Moulding

Clause 7 - Drying

Clause 8 - Burning

Clause 9 - Sorting, Stacking and Transport

Frequently Asked Questions4

What is the main advantage of the semi-mechanized process over hand-moulding?+

It produces more uniform, denser, and stronger bricks due to better clay preparation in a pug mill and consistent moulding through a machine (Clause 5 & 6).

What type of soil is considered good for brick making according to this guide?+

Silty clay or sandy clay with a plasticity index between 15 and 25, and low soluble salt content (<1%) is generally suitable (Clause 4.1).

What kind of kiln is typically used in this process?+

The guide suggests continuous kilns like the Bull's Trench Kiln (BTK) or Hoffmann Kiln are suitable for the scale of semi-mechanized production (Clause 8.1).

How does this code relate to IS 1077 and IS 3495?+

IS 11650 provides the 'how-to' for manufacturing bricks, while IS 1077 specifies the required final dimensions and quality of the bricks, and IS 3495 describes the methods to test if those quality requirements are met.

QA/QC Inspection Templates

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QA/QC templates coming soon for this code.

Browse all 300 templates →

IS 11650 : 1991Guide for the manufacture of standard burnt clay building bricks by semi-mechanized process

PDF Google Compare BIS Portal

Link points to Internet Archive / others. Not hosted by InfraLens. Details

EN 771-1 · ASTM C62 · AS/NZS 4455.1

CurrentSpecializedGuidelinesMaterials Science · Clay and Stabilized Soil Products

PDF Google Compare BIS Portal

Link points to Internet Archive / others. Not hosted by InfraLens. Details

Guide for the manufacture of standard burnt clay building bricks by semi-mechanized process

Overview

Status: Current
Usage level: Specialized
Domain: Materials Science — Clay and Stabilized Soil Products
Type: Guidelines

International equivalents

Typically used with

IS 1077 IS 2117 IS 2248 IS 2720

Also on InfraLens for IS 11650

6Key values 2Tables 4FAQs

Practical Notes

! Ensure the clay is free from 'kankar' (calcareous nodules), as they can cause bricks to spall or burst upon wetting after firing.

! The semi-mechanized process, particularly the use of a pug mill and extruder, yields bricks with higher density and uniformity compared to the hand-moulding process described in IS 2117.

! Careful control of the firing schedule (temperature and atmosphere) in the kiln is critical to prevent defects like black cores, brittleness, or bloating.

Frequently referenced clauses

Cl. 4Raw Materials Cl. 5Preparation of Brick Earth Cl. 6Moulding Cl. 7Drying Cl. 8Burning Cl. 9Sorting, Stacking and Transport

claysoilbricks

International Equivalents

Similar International Standards

EN 771-1:2011+A1:2015CEN (European Committee for Standardization), Europe

LowCurrent

Specification for masonry units - Part 1: Clay masonry units

Specifies the performance characteristics of the final clay brick, which is the goal of the IS 11650 manufacturing guide.

ASTM C62-17ASTM International, USA

LowCurrent

Standard Specification for Building Brick (Solid Masonry Units Made From Clay or Shale)

Defines the grading and properties of finished building bricks, not the manufacturing process itself.

BS 3921:1985BSI (British Standards Institution), UK

LowWithdrawn

Specification for Clay Bricks

Formerly specified requirements for clay bricks in the UK, focusing on the final product rather than the manufacturing method.

AS/NZS 4455.1:2008Standards Australia/Standards New Zealand, Australia/New Zealand

LowCurrent

Masonry units, pavers, flags and segmental retaining wall units, Part 1: Masonry units

Sets performance requirements for finished masonry units, leaving manufacturing details to the producer.

Key Differences

Key Similarities

≈The fundamental objective is the same across all standards: to produce sound, durable, and regularly shaped burnt clay bricks suitable for building construction.

≈All standards are based on the use of clay and/or shale as the primary raw material for brick production.

≈The implied manufacturing sequence of raw material preparation, shaping, drying, and firing is common, even though only IS 11650 explicitly details the steps.

≈All standards recognize proper firing (vitrification) as the critical step for achieving key properties like compressive strength, durability, and low water absorption.

Parameter Comparison

Parameter	IS Value	International	Source
Water Absorption (Target)	Aims for < 20% by weight (24-hr cold immersion) for a well-burnt brick.	Grade SW: ≤ 17.0% (avg); Grade MW: ≤ 22.0% (avg) for 5-hr boil test.	ASTM C62-17
Compressive Strength (Target)	Process aims to meet classes in IS 1077, starting from 3.5 N/mm² (MPa).	Grade SW: ≥ 20.7 N/mm² (3000 psi) avg; Grade MW: ≥ 17.2 N/mm² (2500 psi) avg.	ASTM C62-17
Raw Material - Sand Content	Recommends soil with 20-30% sand.	Not specified; performance-based, allowing any suitable composition.	EN 771-1 / ASTM C62
Process Control - Drying Shrinkage	Linear drying shrinkage of prepared clay should be less than 7%.	Not specified for the final product; considered an internal process control parameter for the manufacturer.	EN 771-1
Process Control - Firing Temperature	Suggests a firing range of 900–1100 °C.	Not specified; left to manufacturer to determine optimal firing for their materials to meet performance requirements.	ASTM C62-17
Efflorescence	Aims for 'Slight' or 'Nil' rating when tested as per IS 3495 (Part 3).	Qualitative requirement to be 'not effloresced' when tested as per ASTM C67.	ASTM C62-17
Dimensional Tolerances	The process guide aims to produce bricks meeting tolerances in IS 1077 (e.g., Length ±3mm, Width ±1.5mm for modular bricks).	Specifies tolerance categories (e.g., T1, T2, Tm) based on mean dimension vs. work dimension.	EN 771-1

⚠ Verify details from original standards before use

Key Values6

Quick Reference Values

Recommended plasticity index for brick clay15 - 25

Recommended liquid limit for brick clay30 - 45 percent

Maximum allowable soluble salts in clay< 1 percent

Water required for pugging (tempering)12 - 18 % by weight of clay

Typical firing temperature range900 - 1100 °C

Maximum linear drying shrinkage7 - 10 %

Tables & Referenced Sections

Key Tables

Table 1 - Guide for Selection of Site for a Brick Plant

Table 2 - Classification of Brick Earth

Key Clauses

Clause 4 - Raw Materials

Clause 5 - Preparation of Brick Earth

Clause 6 - Moulding

Clause 7 - Drying

Clause 8 - Burning

Clause 9 - Sorting, Stacking and Transport

Frequently Asked Questions4

What is the main advantage of the semi-mechanized process over hand-moulding?+

It produces more uniform, denser, and stronger bricks due to better clay preparation in a pug mill and consistent moulding through a machine (Clause 5 & 6).

What type of soil is considered good for brick making according to this guide?+

Silty clay or sandy clay with a plasticity index between 15 and 25, and low soluble salt content (<1%) is generally suitable (Clause 4.1).

What kind of kiln is typically used in this process?+

The guide suggests continuous kilns like the Bull's Trench Kiln (BTK) or Hoffmann Kiln are suitable for the scale of semi-mechanized production (Clause 8.1).

How does this code relate to IS 1077 and IS 3495?+

QA/QC Inspection Templates

📋

QA/QC templates coming soon for this code.

Browse all 300 templates →

IS 11650 : 1991Guide for the manufacture of standard burnt clay building bricks by semi-mechanized process

Overview

International Equivalents

Key Values6

Tables & Referenced Sections

Related Resources on InfraLens

Frequently Asked Questions4

QA/QC Inspection Templates

IS 11650 : 1991Guide for the manufacture of standard burnt clay building bricks by semi-mechanized process

Overview

International Equivalents

Key Values6

Tables & Referenced Sections

Related Resources on InfraLens

Frequently Asked Questions4

QA/QC Inspection Templates