Quantity estimation of materials is a vital part of construction projects, as it helps ensure cost efficiency and prevents material wastage. The calculation of bricks, cement, and sand depends on the mix proportions of the mortar and the dimensions of the masonry. In this article, we will explore the step-by-step process of estimating these materials, using an example for clarity. Let’s get started!
Assumptions
For this calculation, let us assume the following:
- Volume of brickwork: 1 m³
- Mortar grade: 1:6 (cement:sand)
- Brick size: 190 mm x 90 mm x 90 mm
- Mortar thickness: 10 mm = 0.01 m
Step 1: Calculate the Number of Bricks
Step 1.1: Volume of One Brick (With and Without Mortar)
- Volume of one brick without mortar:
0.19×0.09×0.09=0.001539m3
- Volume of one brick with mortar:
(0.19+0.01)×(0.09+0.01)×(0.09+0.01)=0.2×0.1×0.1=0.002 m3
Step 1.2: Number of Bricks Required
No. of bricks = Volume of brickwork/Volume of one brick with mortar
No. of bricks=1.0/0.002=500
Step 1.3: Add Wastage
Consider 10-15% extra bricks as wastage:
Total no. of bricks=500+(10% of 500)=550
Step 2: Calculate the Quantity of Mortar
Step 2.1: Volume Occupied by Bricks
Volume of bricks=No. of bricks×Volume of one brick without mortar
Volume of bricks=500×0.001539=0.7695m3
Step 2.2: Volume of Mortar
Volume of mortar=Volume of brickwork−Volume of bricks
Volume of mortar=1.0−0.7695=0.2305m3
Step 3: Calculate the Quantity of Cement and Sand
Step 3.1: Dry Volume of Mortar
The dry volume of mortar accounts for a 54% increase due to water shrinkage:
Dry volume of mortar=1.54×Volume of mortar
Dry volume of mortar=1.54×0.2305=0.35497m3
Step 3.2: Cement Quantity
Cement volume= (Dry volume of mortar×Cement ratio) / Sum of ratios
Cement volume=( 0.35497×1) / 1+6 = 0.35497 / 7 =0.05071 m 3
Convert the volume of cement to weight:
Cement weight=0.05071×1440=73.0224 kg
No. of cement bags= 73.0224 / 50 =1.45 bags
Step 3.3: Sand Quantity
Sand volume= (Dry volume of mortar×Sand ratio ) / Sum of ratios
Sand volume = (0.35497×6) / 7 = .30426 m3
Convert the sand volume to cubic feet (cft):
Sand volume = 0.30426×35.3147= 10.7448cft
Summary of Materials
Based on the above calculations, the required materials are:
- Bricks: 550
- Cement: 1.45 bags (50 kg per bag)
- Sand: 0.30426 m³ or 10.7448 cft
Key Takeaways
- Always add an extra margin for wastage during construction, especially for bricks.
- Ensure the mortar mix ratio aligns with project specifications.
- Double-check material quality to achieve strong and durable masonry.
Accurate material estimation helps in cost control, ensures efficient resource allocation, and reduces wastage. By following this step-by-step process, you can confidently calculate the quantities needed for any brick masonry project.
Is Codes for brick masonry
In India, brick masonry is governed by several IS (Indian Standards) codes to ensure quality, durability, and safety in construction. Here are some key IS codes relevant to brick masonry:
- IS 1077:1992
Specification for Common Burnt Clay Building Bricks
This code specifies the requirements for dimensions, classification, physical requirements, and tolerances of burnt clay bricks. - IS 2212:1991
Code of Practice for Brickwork
This standard provides guidelines for the construction of brick masonry, including laying methods, mortar types, and joint finishing. - IS 3495 (Parts 1 to 4):1992
Methods of Tests of Burnt Clay Building Bricks
It includes tests for determining the compressive strength, water absorption, efflorescence, and warpage of bricks. - IS 1905:1987
Code of Practice for Structural Use of Unreinforced Masonry
This code deals with the structural use of unreinforced masonry, including design, construction, and stability requirements. - IS 4031 (Parts 1 to 15)
Methods of Physical Tests for Hydraulic Cement
Though not specific to brick masonry, this code outlines the testing of cement used in brickwork. - IS 2645:2003
Integral Waterproofing Compounds for Cement Mortar and Concrete
This is useful for ensuring waterproofing in mortar used for brick masonry. - IS 5454:1978
Methods for Sampling of Clay Building Bricks
This standard provides procedures for sampling bricks for testing purposes. - IS 2572:2005
Code of Practice for Construction of Hollow and Solid Concrete Block Masonry
Though primarily for concrete blocks, some principles may also apply to brick masonry.
These codes should be referred to while planning, executing, and inspecting brick masonry work to meet the required standards and ensure a high-quality construction.
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Conclusion🎯
Accurate material estimation is the backbone of any successful construction project. Knowing how to calculate the quantity of bricks, cement, and sand ensures cost efficiency, minimises material wastage, and enhances the overall quality of the masonry work. By following a systematic approach like the one detailed above, you can effectively plan and execute your project without delays or shortages. Always remember to account for wastage, adhere to the specified mix ratios, and verify the quality of materials to achieve durable and structurally sound brick masonry. With these steps, you are well-equipped to handle material estimation confidently and professionally.