Material constants in building works
1982 Edition

Material Constants in Building Works – Overview and Essential Tables

Foreword Summary:

• Presents material constants excluding wastage for typical building elements.
• Wastage differs with geography, source, climate, and usage; local evaluation is necessary.
• Water-cement ratio targets an approximate flow of 110 ± 5%.

Principal Tables:

1. Mortar Material Constants (per cubic meter of mortar)

2. Concrete Material Constants (per cubic meter of concrete)

Scope and Fundamental Material Constants

Scope (Clause 1.1)

• Defines material constants excluding wastage for standard building materials.
• Wastage percentages depend on local conditions and must be evaluated by users.
• Not a comprehensive list; will be expanded as more data is acquired.

Core Material Constants for Concrete Mixes (Clause 2.2, Table 2.4)

• For crushed aggregates, constants increase by 5% for lean mixes and 7% for richer mixes.
• Lime concrete and specialty finishes have distinct constants as detailed in IS 10067.

Summary of Material Constants in IS 10067

1. Material Constants for Concrete (Clause 2.2)

• Table 2 lists standard values for cement concrete and lime concrete.
• Includes quantities for cement, water, fine and coarse aggregates, and lime for lime concretes.

2. General Guidance

• Constants exclude wastage quantities.
• Wastage varies due to environmental and handling factors; local assessment needed.
• Values are rounded according to the standard’s prescribed rules.

Sample Table for Concrete Material Constants

Refer to the most current IS 10067 edition for precise figures.

Usage Recommendations

• Employ these constants to estimate material volumes for construction tasks.
• Factor in wastage and site-specific conditions.
• Consult IS 10067 for comprehensive tables and rounding instructions.

flowchart TD
    A[Material Constants] --> B[Cement Concrete]
    A --> C[Lime Concrete]
    B --> D[Table 2: Cement, Water, Aggregates]
    C --> E[Table 2: Lime Content, Aggregates]
    F[User] --> G[Adjust for Wastage]

Mortar Mix Ratios and Material Constants

Mortar Mix Types and Quantities (Table 2.4, Clause 2.1)

• Water-cement ratio aims for a flow of approximately 110 ± 5%.
• Sand used typically has a fineness modulus near 1.26, aligned with IS 1542 and IS 2116.

Mortar for Brick Masonry (Clause 2.9, Table 3)

Concrete Mix Ratios and Material Constants (Table 2, Clause 2.2)

• For mixes using crushed aggregates, increase material constants by 5% for lean mixes and 7% for richer mixes.

Cement Concrete Flooring Material Data (Table 5, Clause 2.4.1)

Material Constants for Brick Masonry

Conventional Bricks (approximate size 2.9 x 11.1 x 7.0 cm with 1 cm mortar joints)

Mortar volume per cubic meter of brickwork: 0.234 m³ (frog up), 0.203 m³ (frog down) Sand and cement quantities may be reduced by 2% if coarse sand (FM 2.9) is used.

Modular Bricks

Material Constants for Flooring Applications

Cement Concrete Flooring (Clause 2.4.1, Table 5)

• Mix ratio: 1 : 2 : 4 (Cement : Sand : Shingle with nominal 20 mm size)
• Floating coat made from neat cement for finishing.
• Material quantities increase by approximately 7% if crushed aggregate substitutes shingle.

Terrazzo (Marble Chips) Flooring (Clause 2.4.2, Table 6)

• Under layer consists of 1:2:4 cement concrete with 20 mm nominal aggregate.
• Top layer is composed of marble chips combined with a binder of cement and marble powder.

Notes:

• Quantities calculated per 10 m² of flooring area.
• Thickness and mix proportions are critical for durability and surface finish.
• Floating coat enhances surface smoothness and longevity.

Detailed Material Constants for Cement Concrete Flooring

Material Quantities per Thickness (Clause 2.4.1, Table 5)

• Note: For crushed aggregate use, increase material quantities by 7%.

Concrete Mix Constants (Clause 2.2, Table 2)

• Increase constants by 5% for lean mixes and 7% for richer mixes when using crushed aggregates.

Mortar Mix Constants (Clause 2.1)

Material Constants for Terrazzo Flooring (Clause 2.4.2, Table 6)

Key Details:

• The under layer is standard cement concrete (1:2:4) with 20 mm nominal aggregate.
• The top layer is a mixture of marble chips and a binder composed of cement and marble powder in a 3:1 weight ratio.
• Total thickness is 40 mm, with chip sizes and binder ratios varying by finish.

Binder Mix Formula for Top Layer:

[ \text{Binder} = \text{Cement} + \text{Marble Powder} \quad \text{in a 3:1 weight ratio} ]

[ \text{Marble Chips} : \text{Binder} = 1 : 1 \quad \text{by weight} ]

flowchart LR
    A[Under Layer: 30-35 mm CC 1:2:4]
    B[Top Layer: Marble Chips + Binder]
    C[Binder = Cement + Marble Powder (3:1)]
    A --> B
    B --> C

Plaster Mix Ratios and Material Constants (Clause 2.5, Table 7)

Note: Joints and raking depths considered as 1 cm for these calculations.

Sand and Aggregate Standards

• Fine sand conforming to IS 2116 is recommended for plaster work.
• Sand for masonry mortars should be clean, sharp, and well graded.
• Coarse and fine aggregates for concrete shall comply with IS 383 (Second Revision).

Mortar Mix Constants (Clause 2.1, Table 2.4)

Key Notes on Material Wastage and Sand Fineness Modulus (Clause 2.2.2 and Related Sections)

Fineness Modulus (FM) of Aggregates

• Fine aggregate FM:
  • Lean mixes typically use fine sand with FM ~1.26.
  • Rich mixes use coarser sand with FM around 2.87.
• Coarse aggregate FM:
  • Lean mixes: approximately 6.9.
  • Rich mixes: approximately 6.5.
• Aggregate grading follows IS 383-1970 standards.

Material Constants for Concrete Mixes (Table 2.4)

Note: For crushed aggregates, increase constants by 5% (lean mixes) or 7% (richer mixes).

Material Wastage Guidelines

• IS 10067 provides constants excluding wastage.
• Wastage rates vary with location, season, material source, and handling practices.
• Users must apply appropriate wastage factors based on local experience.
• Typical wastage allowances range from 2% to 10% depending on material and circumstances.

IS 10067 (1982) presents essential material constants for building design and construction, including:

Fundamental Material Properties (Representative Values)

Notes:

• Density is used for self-weight and load calculations.
• Modulus of Elasticity (E) is vital for stress and deformation assessments.
• Poisson's Ratio (ν) helps in analyzing multi-directional stress effects.
• Thermal expansion coefficients are essential for temperature-induced deformation calculations.

Application:

• Refer to IS 10067 for specific material grades and conditions.
• These constants are used in structural analysis, design calculations, and detailing.

flowchart LR
    A[Material Constants] --> B[Density]
    A --> C[Modulus of Elasticity]
    A --> D[Poisson's Ratio]
    A --> E[Thermal Expansion]

Always verify values with the latest IS 10067 for accurate design.