Units of Measure
Units of measurement in Construction Activities
During estimation, it is a fundamental requirement that quantities should be consistent in Units. Apart from this, the estimator must have knowledge of which quantity in civil Engineering construction we should consider in square and volumetric form. Where the thickness is negligible then we usually consider the surface area for estimating material, if there is marked thickness then we consider the volume for estimation by multiplying surface area with thickness. This article comprises the complete details of a unit of measurement along with construction activities for a small civil engineering structure.
A Brief History of Unit of Measurements
Measurement; it is the measure of size, length, and amount. As long as (18th century) the unit of measurement came as a cohesive system. Before that, the unit of measurement did not exist. Although there was a country France who had some system of measurement.
There are many systems of measurement which has been taken by human morphology like foot and pace. But this system of measurement was not considered standard Because these are a lot in numbers. For standard, there should be one system of the unit of measurement which should be consistent throughout the world.
let’s discuss the brief history of the measurement of length, and weight as these are the most important measurement in civil engineering construction
Measurement of Length
Length is the measurement that is used to consider most important in life. Feet, inches, meter are the example length. From the first day, it was most important the measurement of land in civil engineering surveying. In history, it was measured by placing the rods and bars in public places. This tool was considered standard and soon distributed in the community
Measurement of Weight
The measurement of weight in history was not as simple as length. But history also tells us that humanity always found the solution to complex problems. So there were people who got a solution for the measurement of weight. the size of wheat grain was standardized, by considering the weight of grain they used to measure the weight of other materials.
System of Units and Types
In science, there is a certain system of units that are used to measure any physical quantity.
There are three main types of system of units
MKS (meter kilogram second)
In MKS system of Units, meter kilogram and second are the base units of length, mass and time. All other quantities in the MKS system such as force, velocity is derived from these base units
FPS (foot-pound and second)
In the FPS system of Units, foot-pound and second are the base units of length mass and time.
CGS (centimeter gram and second)
In the CGS system of units, centimeter, gram, and second are the base units of length, mass, and time.
Basic Conversion Table
Civil Engineering Construction Activities
Civil Engineering Construction Activities and their units of Measurements
For the calculation of materials and then making a bill of quantity (BOQ), the knowledge of units of measurement for different construction activities is a fundamental requirement. The activities from excavation to Roofing for a small civil engineering structure and their units of measurement are discussed below.
Earthwork is the excavation of soil for foundation and then backfilling of soil. It is measured in volumetric (volume) units. Their units are cubic meter (m3) cubic feet (ft3) and cubic centimeter (cm3) in MKS, FPS, and CGS system Respectively. Volume can be easily computed by multiplying width length and height of the foundation.
Concrete in Foundation
The PCC concrete for the foundation is measured in volumetric (volume) units. It can be computed by multiplying length width and thickness of the layer. The length and width are usually the same as for the excavation of the foundation. The thickness usually varies from 9” to 18”
When the soil is soft, a layer of dry brick is usually provided before the concreting in the foundation. Its is measured in square units by multiplying the length and width of the excavation area
Damped Proof Course
Damped proof course (DPC) is 1” thick rich concrete or 0.75” thick mortar, which is provided at the plinth level of the floor to retard the movement of water upward due to capillary action. It is measured in square units by multiplying the length of excavation with the width of the wall. For the determination of the quantity of material for DPC, it can be multiplied with a thickness
Masonry is the brick and mortar work and is measured in volumetric (volume) units. It can be computed simply by the length width and height of the wall. The Measurement of Masonry work for foundation is usually separate from the masonry work for the superstructure because in foundation the width of each step varies from the previous one. Although both are measured in the cubic unit.
RCC and RBC Work
Reinforced cement concrete work and Reinforced brick concrete work (RBC) for roofing flooring, beam, column, and other concrete structural members are measured in volumetric (volume) units. Although steel in RCC is measured in the form weight (kg). the centering and shuttering for concreting is measured in square units
Flooring and Roofing
Flooring and Roofing are measured in square units. As it has different layers of materials so while during the calculation of material we usually multiply the area of flooring and roofing with a thickness of the particular material layer.
Plastering and Pointing
Plastering is measured in square units. While during the calculation of material for plastering the plastering thickness is usually taken 12mm. like plastering pointing is also measured in square units
Units of Measurements for various Construction Activities in Tabular Form
From the above article, it can be concluded that understanding the units of measurements for various construction activities is one of the fundamental requirements for the estimation of material and bill of quantity (BOQ). There are some notable points which cannot be ignored
While during the conversion from the MKS system to FPS system conversion tables should be used because one wrong conversion can increase the cost of the project.
Estimators must know which quantity they have to measure in volumetric and square units.