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# Student Corner

Design Calculation for Slab

INTRODUCTION
A slab is a structural element that is used to support ceilings and floors. It is made of concrete and reinforcements are provided to support it. It is several inches thick and it rests on beams and columns. It is estimated that a concrete slab lasts for about 30 to 100 years if it is built with good grade of concrete and steel. Usually for residential purpose M20 is used.

Design Calculation of an Isolated Footing

INTRODUCTION
Footings are the bases laid on the soil on top of which a structure is erected. Thus, it is the foundation on which a building or any such structure stands upon. They are made of concrete having reinforcements inside them and are poured into an excavated ditch or conduit. Before the foundation is built, a test is done to assess the strength ofthe soil bearing capacity to ascertain the type of foundation to be built.

Given below are the types of footing and the situation under which they are applied is defined for better understanding-

What are various Types of Admixtures?

INTRODUCTION

Types of Contracts in Construction Management

INTRODUCTION
Contracts provide a legal framework or a set of protocols to be carried out to establish a legal settlement between the two parties involved. It avoids any such unnecessary confusion that may arise leading to disputes. These are the keys to guide business relationships across all sectors. Not only that, these are helpful for contractors to better estimate the time and money to be used up in the project. Also, it helps the contractors to utilise their powers for gaining maximum profit out of it.

When contracts are not met as per the requirements, then action has to be taken at the initial stages, otherwise conflicts may arise leading to unprofessionalism and disputes. Contracts address labour requirements, incentives involved, money matters, time of delivery, economic construction, choice of equipment, and so on. Thus, it is essential if the construction works are to be carried out smoothly.

Factors Affecting Strength And Workability Of Concrete

INTRODUCTION
Strength and workability are both dominating factors in the making of concrete. Strength can be increased by increasing cement content but this in fact reduces the workability. Moreover,the water content can be increased for better workability, but this affects the strength. Hence,a perfect balance is to be maintained for both strength and workability. Furthermore, besides cement and water content, some other factors contribute greatly, which will be discussed as follows.

BILL OF QUANTITIES (BOQ)

INTRODUCTION
It consists of various items of work in the form of a statement depicting quantities, description and rate per unit. It is used to define the quality and quantity of works to be carried out by main contractor for completing work. It is made in tabular format and is mainly used for inviting tender and supplied to contractors to fill up the rates. On receipt of tenders the rates are compared and decision is made regarding the work. It is prepared by quantity surveyors and building estimators to be handed over to contractor.

Calculation Of Materials For Plastering

Here, we will be calculating the quantities of materials i.e., cement and sand, required for plastering. We will take 100 sq. metre area of wall and calculate accordingly. Moreover, some extra percentages are taken on volume for other construction works during the process.

Assuming thickness of plastering,
Inside = 12 mm
Outside = 20 mm
Ceiling = 6 mm

Mortar Calculation in Brickwork

Size of brick with Mortar = 20 cm × 10 cm × 10 cm

No. of bricks required per 1 m3 brickwork = 1 / (0.2 × 0.1 × 0.1) = 500 nos.

No. of bricks for 10 m3 brickwork = 500 × 10 = 5000 nos.
Size of brick without Mortar = 19 cm × 9 cm × 9 cm
Actual volume of 5000 bricks = 5000 × (0.19 × 0.09 × 0.09) = 5000 × 0.001539 = 7.695 m3
approx 7.7 m3

Common Abbreviation Used in Civil Engineering

CIVIL ENGINEERING ABBREVIATION:
The common abbreviation used in civil engineering are as follows:

A.A.S.H.T.O – American Association of State Highway Transport
A.B – Anchor Bolt Or Asbestos Board
A.C.I – American concrete institute.
A.R.E.A – American Railway Engineering Association.
A.S.C – Allowable stress of concrete.
A.S.T.M – American Society for Testing Materials
AC – Asphalt Concrete
AE – Assistant Engineer
APM – Assistant Project Manager

Cutting Length of Stirrups

By
Sourav Dutta
Manager-Civil

We generally designate stirrups by its external dimensions. For example, a 250mm x 300mm stirrup has the 250mm and 300mm dimensions in perpendicular directions as shown in Fig 1.

Now a stirrup has 2 bends, types of which are shown in Fig 1 and Fig 4. Guideline of minimum bend length is as per Cl.3.8 of BIS2502 (shown in Fig 3).