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Which type of foundation should be used in Coastal Area and Sloping ground?
CB Sowmya
For sloping ground Filled foundation Fill and cut foundation Stepped foundation For coastal areas Pile foundation - with or without bracings Well foundation To know more about foundations for different ground conditions, https://theconstructor.org/geotechnical/construction-foundation-different-grounRead more
For sloping ground
For coastal areas
To know more about foundations for different ground conditions,
https://theconstructor.org/geotechnical/construction-foundation-different-ground-conditions/7606/
See lessWhich type of foundation is best for black cotton soil?
CB Sowmya
Under reamed piles are best suited for black cotton soil.
Under reamed piles are best suited for black cotton soil.
See lessWhat Reinforcements are used in the Process of Prestressing?
CB Sowmya
The type of steel used in prestressing may be: Cold worked steel Stress relieving steel Strain tampered steel The following properties of the steel are appreciated: High strength property of steel (min of 980 Mpa for bars) Adequate ductility Bendability ( for harping ) High bond strength (Crucial foRead more
The type of steel used in prestressing may be:
The following properties of the steel are appreciated:
Note that the permissible stress in prestressing steel is not more than 80% of yeild strength.
Permissible stress = 0.8fy
This fy is found just like any HYSD bar by considering the 0.2% proof stress.
See lessWhy should curing not be done by ponding and polythene sheets?
CB Sowmya
Both methods are very advantageous based on the need for the structure. The disadvantages are as follows Pond curing: Can only be used for flat surfaces Cannot be used where water is scarce Needs continuous supervision Unlike steam curing, it does not accelerate the strength gaining process The pondRead more
Both methods are very advantageous based on the need for the structure. The disadvantages are as follows
Pond curing:
Polythene sheets
What is Waste Stabilization Pond?
CB Sowmya
Waste stabilization ponds are used for treating wastewater. They are just like ones but man-made. Large ponds are constructed and they maybe link with one another to enhance the waste stabilization. These ponds make use of the principles of sedimentation, filtration, nitrification, denitrification aRead more
Waste stabilization ponds are used for treating wastewater. They are just like ones but man-made. Large ponds are constructed and they maybe link with one another to enhance the waste stabilization. These ponds make use of the principles of sedimentation, filtration, nitrification, denitrification and biodegradation. These ponds will reduce the solids, BOD, and Pathogens in the effluents. They have low operating costs and do not require electricity. If designed properly, they can be odor-free. However, they require large areas and highly accurate design and construction.
There are three types of pond
This methods produces a low quality effluent which has to be further treated before disposal.
See lessWhat is Vena Contract in Orifice?
CB Sowmya
Vena contracta is a section in the flow of water where the flow has considerably narrow. Vena contracta can be found when there is a sudden change in the cross-sectional area. The streamlines of the fluid cannot change abruptly when the CS area changes. This sudden reduction in the cross-sectionalRead more
Vena contracta is a section in the flow of water where the flow has considerably narrow. Vena contracta can be found when there is a sudden change in the cross-sectional area. The streamlines of the fluid cannot change abruptly when the CS area changes. This sudden reduction in the cross-sectional area makes the streamlines converge and form the vena contracta.
In this section, the velocity of the flow is maximum. From Vena contracta we can find the coefficient of contraction.
Further, Vena contracta has wide use in studying the blood flow and in various treatments ad diagnoses like echocardiography.
See lessWhat is Bursting Reinforcement?
CB Sowmya
Bursting reinforcements are provided in Post-tensioned prestressed members or where bursting forces are prevailing. In post-tensioned members, the transfer of stress is through the anchorage blocks. The concrete in the vicinity of the anchorage block up to the length of the larger transverse dimensiRead more
Bursting reinforcements are provided in Post-tensioned prestressed members or where bursting forces are prevailing. In post-tensioned members, the transfer of stress is through the anchorage blocks.
The concrete in the vicinity of the anchorage block up to the length of the larger transverse dimension of the structure is defined as the anchorage zone. This anchorage zone is very high in bursting forces. These bursting forces can be computed using the stress trajectory studies.
From the stress trajectories, bursting forces can be found and corresponding bursting reinforcements can be provided. These reinforcements are also called the end zone reinforcement or bursting links. This zone can be cast separately using a high grade of concrete to ensure safety.
See lessWhy is propping required for long structures once the formwork is removed?
CB Sowmya
The formworks are removed after the concrete has reached a strength at least twice its removal stress. But the members should be supported with the help of props. The reason is because of creep due to the Interfacial transition zone (ITZ). The interfacial transition zone is formed in the concrete beRead more
The formworks are removed after the concrete has reached a strength at least twice its removal stress. But the members should be supported with the help of props. The reason is because of creep due to the Interfacial transition zone (ITZ).
The interfacial transition zone is formed in the concrete between the aggregates and the mortar. This zone comprises of high Water cement ratio and hence is the weakest part of the concrete. Due to the high WC ratio, the hydration reaction in the ITZ produces a porous framework in the early stages. This porous network will be filled in subsequently by stronger gels such as CSH gel as the hydration reaction proceeds. But for this to take place, sufficient time is needed. As time increases, the ITZ becomes stronger.
This is why the creep coefficient reduces as we delay the age of loading. When the props are moved, the self-weight of the structure acts on it, which is equivalent to loading the structure.
We know that the creep coefficient when loaded at
Seven days – 2.2
28 days – 1.6
One year – 1.1
Due to the high creep coefficient, the structure may become susceptible to sagging when the props are removed soon.
See less