Illustration of stress-strain curve for concrete and steel

This construction video tutorial will teach you the detailed process for creating the design of stress-strain curve of concrete and steel by adhering to the IS 456:2000. Limit State Method is used here for these curves.

As the tensile strength of concrete as compared to compressive strength is very week, it can only withstand compressive stress. Alternatively, the tensile strength of steel is very strong and it can withstand both tensile and compressive strength.

While going to design a structure located in costal area and as per IS code the minimum grade of concrete for this structure should be M30 and concrete can’t be used below this grade. It is known that 30th characteristic strength of concrete cube of size 150 mm at 28 days. The characteristic strength is represented with the symbol as fck.

The stress-strain curve for hardened cement paste is nearly linear. The aggregate is more stiff as compared to the cement paste and will consequently deform less (i.e. contain a lower strain) under the similar applied stress.

The stress strain curve of concrete remains among those of the aggregate and the cement paste. But this alliance is non-linear over the most of the range. This non-linear behavior occurs because of formation of micro-cracks for the following reasons :-

(i) At the interface among aggregate particles and cement paste due to the differential movement among the two phases, and
(ii) Inside the cement paste itself.

These cracks are developed owing to variations in temperature and moisture and the application of load.

To learn the detailed process, watch the following video tutorial.

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Published By
Rajib Dey
www.constructioncost.co

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5 Methods of Calculating Quantities of Materials

There are many methods used for calculating quantities of materials. Which one goes with your plan depends on the design and shape of the building. Each method is characteristically different from other.

Calculation of quantities of material needs a proper technical understanding of materials and construction. The five major methods are described here for you and they come up with the right measurement of materials you need.

1. Centre Line Method: Centre line method is applicable to the square building with symmetrical offsets. To calculate the quantities of materials, you need to multiply the total centre line length with breadth and depth of the construction.

The centre line length will be reduced by half of breadth of every junction where the main wall is joined with the cross walls, partitions or verandah. The junctions must be taken into consideration while calculating the centre line length of a wall. The quantity estimation brought out by this method is accurate and fast.

2. Crossing method: Crossing method is designed for calculating materials needed for masonry walls. In this method, the lengths and breadths of walls at plinth level (the base on which a column is raised) are included. The internal dimension of the room and the thickness of the walls are also important to calculate the quantities. Symmetrical offsets should be counted as they play a major role in the calculation of quantity of materials.

3. Out to out and in to in method: This method follows P.W.D system for computing materials and this seems to be the most accurate method among all.

4. Bay method: This bay method is applicable in garages, factory, and railway platform where identical structures are visible. Bay in a construction term means a compartment of a building. The cost of one room is calculated first and it is multiplied by the number of bays.

5. Service unit method: The term service unit method is designed for building with identical rooms. This method is applicable in the construction of college, hospital, cinemas, prison, and more. When it is a construction of a hospital, the service unit will be a bed. Likewise, for cinema/stadium, it is seats.

Calculating quantities of materials follow the above-mentioned methods. Each of which shows a different perspective of calculation and they are also concentrated on different construction types.

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Published By

Rajib Dey

www.constructioncost.co

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How to choose pile foundation on the basis of cost versus other foundations for construction project

Get detailed information on how to choose the pile foundations on the basis of cost vs. other foundations for construction projects and factors which impact the cost of pile foundation.

Sometimes, it becomes difficult for structural designer to take stable decision to select types of foundations like pile foundation or ordinary strip or mat foundation to be used for the structure.

The problem becomes acute while going to choose among pile foundation and traditional mat or strip foundation developed in a deeper level to fit a soil layer having desirable bearing strength.

There should be an indicator for all construction conditions under which the use of pile foundation is considered as inexpensive with reference to traditional strip and mat foundations.

This article will focus on the variations through which the decision for choosing of pile foundation over other foundation types can be taken without difficulty. This condition line is formed on the reasonably detailed cost appraisal of the foundation. The foundation cost is impacted by the following factors :-

Factors impacting the cost of Pile Foundation

Evidently, final decision for employing the type of foundation, cannot be taken on the basis of the calculation of excavation volume and concrete quantity of deep mat or strip foundation with regard to cost of piles that support the same load.

A cap is needed for Pile foundation. The density of the cap should be approx 45cm for two piles and 60cm to 120cm for two pair of piles. Plan dimensions of piling cap should be up to 2100mm2 for pile having diameter of 550mm.

With tie beams provided over one direction, the Pile caps are joined together using tie beams in more than one direction.

It is found that, the excavation cost of pile cap along with capping beams and tie beams is two times the cost of machine excavation in moderately large column bases. With the advancement of construction, the perfect structural design as well as stringent supervision is required for pile foundation.

To get more details, click on the following link theconstructor.org

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Published By

Rajib Dey

www.constructioncost.co

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