Properties and benefits of self compacting concrete

Self-consolidating alias self-compacting concrete is an extremely flowable type of concrete that does not need vibration for setting and compaction.

It is compressed into each corner of a formwork perfectly with its self weight exclusive of any external vibrators. It is a fully engineered concrete with greater fluidity.

Self compacting concrete retains all the strength and characteristics of concrete satisfying desired performance requirements.

In some specific conditions the inclusion of superplasticizers and viscosity modifier with the mix, the bleeding and segregation is significantly reduced. The strength is decreased for the concrete that segregates and as a result honeycombed areas are produced next to the formwork. A properly designed SCC mix does not segregate and it retains extreme deformability and outstanding stability characteristics.

Advantages of SCC:

a. Curtailment in site manpower
b. Problems due to vibrators are reduced
c. Easy to set
d. Rapid construction
e. Superior surface finish
f. The strength is enhanced because of superior compaction and uniformity of concrete.

Characteristics Of Self-Compacting Concrete

Self-compacting concrete has strong resistance capacity against segregation with mineral fillers or fines as well as special admixtures. It should have the flexibility to be flown and filled special forms under its own weight, it should be flowable enough to move across highly reinforced areas, and should have the capability to get rid of aggregate segregation. This type of concrete should fulfill special project requirements regarding placement and flow.

Self-compacting concrete having a similar water cement or cement binder ratio will generally contain a marginally higher strength with regard to conventional vibrated concrete, without proper vibration, a superior interface among the aggregate and hardened paste will be created.

The concrete mix of SCC should be set at a considerably higher velocity as compared to traditional concrete. Self-compacting concrete should be set at heights greater than 5 meters devoid of aggregate segregation. It can also be applied in areas with normal and congested reinforcement, with aggregates as large as 2 inches.

Self-Compacting Concrete Uses - Self-compacting concrete is mostly found in bridges and even on pre-cast sections.

a. Conclusion
b. Self compacting concrete can save time, cost as well as improve strength.
c. SSC can be efficiently transformed into congested reinforced areas like columns, drilled shafts.

To get more details, go through the following link csengineermag.com



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Published By
Rajib Dey
www.constructioncost.co
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Some useful tips to restore active cracks in concrete

Active cracks in concrete stand for live cracks which are broaden in length, width, and depth in due course. Because of overloading & thermal enlargement, these cracks are developed e.g. cracks owing to freeze-thaw. There are different types of processes to restore active cracks which range from drilling and plugging, stitching, external pre-stressing and flexible sealing of cracks.

Because of unrestrained growth, there is chance for a new crack to be developed next to the restored active cracks. So, primarily, it is essential to settle reason of crack formation.

How to restore active cracks in concrete

The following processes are commonly used for restoring active cracks in concrete structures.

1. Drilling and Plugging through Crack: This process is suitable for the cracks which are found in straight lines. Under this process, a hole is drilled adjacent to the crack and stuffed with grout. This grout builds the key to lock the crack so that it can’t expand further. The grout avoids leakages and loss of soil. This method is inexpensive and less time is required for that.

Another useful process for plugging the drilled hole is stuffing it with epoxy mortar or any epoxy formulation with reinforcement bars which are arranged in the drilled hole. The bars applied contain predetermined length and size to fasten the cracks across.

The method includes drilling a hole of 50 to 75mm diameter based on the width of crack following the position of crack. The hole should be must be sufficiently big to bisect the crack along its full length and arrange adequate repair material to structurally bear the loads enforced on the key.

If water tightness is mainly required over structural load transmission, then the drilled hole is stuffed with a flexible material having low modulus. If both properties are necessary, the first hole is stuffed with grout and the second hole is stuffed with a flexible material.

2. Stitching of Cracks: Under this process, holes are drilled in such a manner that entry and exit points are provided across the cracks. Through the holes, several U-shaped metallic staples are provided through the holes and the holes are secured firmly at the end with grout or epoxy.

3. External Prestressing: Post-tensioning method is used to close flexural cracks in reinforced concrete. It will stop the cracks to be expanded further or fixed entirely. The process offers compression force so as to correct the tendons and then supplementary residual compressive force.

This process needs anchorage of the tie-rods to the anchoring device tied to the beam.

4. Flexible Sealing: Under flexible sealing method, bond breaker is utilized for repairing active cracks.

Prior to apply a repair method for active cracks, it should be checked that whether it is essential to make the flexural or tensile strength better across the crack. To sustain the strength, it is required to set up an expansion joint close to the repaired crack so that further cracking can’t happen adjacent to the corrected one in due course of time.



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Some useful tips on reinforced concrete design

While designing the reinforced concrete members, it is necessary to check the steel reinforcement in jobsite prior to arrange concrete. Besides, ensure the concrete foundations, beams, columns, etc. are constructed as per design norms. Often, it is observed that steel beam stirrups employed in reinforced concrete design, are not installed properly.

The beam stirrups are extensively utilized in residential construction. In order to produce perfect architectural design and satisfy building occupant requirements, the sizes of concrete beam are made thinner and their lengths are increased.

In our experience, this has been the result of architectural design and. The higher cost of foundation components like drilled piers is also a major concern. To lessen the requirement of extra piers, the lengths of concrete beam are raised and it leads to the application of steel stirrups.

Concrete beams differ in depth. The shear strength of the beam will be increased by making beam deeper. For insufficient depth, steel stirrups should be included to raise the shear strength of the beam. These stirrups generally belong to one piece of steel that is twisted into a rectangular shape. Often small diameter steel like #3 and #4 rebar is applied. The stirrup normally wraps around the bottom and top bars of the beams.

It is essential to indicate the size, distance and position along the length of the beam where the stirrups will be assigned. Besides, the dimensions of stirrup should also be indicated in the sections in order that the stirrup is manufactured before installation.

Stirrups are suitable for the areas of high shear, like bearing points and under large point loads.

The installer should take proper care for fabrication of the stirrup from one piece of steel and sufficiently overlap each end (speak to the Structural Engineer or refer to the ACI code for variations). Sometimes, the stirrup is not pre-fabricated and the installer attempts to produce the stirrup in the field, once the horizontal bars are already in position. It is normal since the stirrup is built up from two pieces with insufficient lap splice.

The method is simple to set up a stirrup simultaneously the horizontal reinforcement is being installed. To avoid last-minute modifications, it is recommended to consult with the Structural Engineer with any confusion regarding size, shape, spacing and installation of stirrups before inspection.



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EdiLus-RC – A powerful software for concrete design & reinforced concrete structural calculation

EdiLus-RC is an exclusive software for making perfect concrete design that deals with structural calculations toward new and subsisting buildings in reinforced concrete by means of the most simple and effective SMART BIM object input.

The first structural calculations BIM software for reinforced concrete buildings.

To use the software, just draw the structural members to input nodes, loads, constraints… the computational model is fully ascertained from the drawing automatically.

With this software, it is possible to design and measure new buildings as well as accomplish checks and structural redevelopments of subsisting reinforced concrete buildings with cladding work, platings, FRP interventions, etc. Particular functions will help in obtaining information concerning the subsisting structure, the material strengths defining its reinforcements.

It is also possible to insert new roof structures to the subsisting building, elevations, or even extra floors, etc., and then move on to an overall validation.

Finite Element Method solver integrated in the software: A FEM solver is added with the software to provide a unitary experience in structural design. Graphical input, the static and dynamic calculations, structural analysis, modifications and construction documents (charts, tables and reports) are all created with the very same software in a simple and incorporated manner.

Graphical analysis of the calculation results: Each object is illustrated with its stress and deformation values once the calculation process is completed. Besides, the detailed calculation leads to numerical form, EdiLus also offers different graphical views that facilitate you to realize how the structure functions at a glance. The process for improvidngh the static or dynamic behaviour of the structure is simple and intuitive.

Object oriented modelling, 3D input based on Magnetic Grids: Design with intelligent objects that comprises of information concerning their characteristics of resistance and spatial location.

The complicated spatial structures can now be easily modeled with Magnetic Grids, the robust tool that facilitates you to develop a network of magnetic points in space where the different structural components are automatically attached.

Automatic reinforcement schedules design: EdiLus can design the reinforcement schedules for all structural members efficiently. A trouble-free and robust editor that facilitates you to freely adjust the reinforcement bars even after the calculation with an immediate re-verification of the structural element.

Structural checks and Technical Reports: EdiLus-RC examines structural elements sections as per the EUROCODES technical provisions and regulations. Structural engineers can easily select the national annex and the response spectrum concerning the country in which the calculations should be done.

Cost Estimating integrated with structural design: The modelled structure creates a dynamic Bill of Quantities automatically, in reality, the complete project, and any consequent variations, are instantly updated in the project’s cost estimate.

Incorporation with the Edificius BIM model: With integration of EdiLus in Edificius, Architecture and Structural engineering issues can be easily interacted facilitating the structural engineer to design and compute all the structural elements precisely.

To download a free trial version, click on the following link www.accasoftware.com



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www.constructioncost.co
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Details of Cast in Situ Concrete Piles and their advantages

Cast In Situ belongs to a construction item or structural member similar to a beam or in this case a Pile that should be built up, assembled or poured at site instead of prefabrication in a factory. Normally, in cast in place or cast in situ construction, concrete is delivered from a batch plant to site where it is poured and compressed into the formwork that is fixed in required shape and dimensions at site.

Cast in situ or cast-in-place piles are cast in position inside the ground; generally in such type of piles, drilling of necessary diameter and depth into the ground is done with an auger drilling device or a drill bit.

There is a helical screw blade generally known as a “fighting blade” inside the device that functions as a screw conveyor to eliminate the drilled out material. Besides, auger drilling an old method known as percussion drilling is also applied for excavating the hole. Under this method, a heavy cutting or hammering bit affixed to a roper or cable is lowered in the open hole or inside a temporary casing.

After entering deep into the ground, a temporary steel casing is lowered in the borehole to safeguard loose soil from dropping in the borehole.

The verticality of the casing should be examined precisely prior to start. Once the optimal depth is attained, the reinforcement cage with vertical rebars and stiffeners is lowered within the borehole, and the upper part is hanged at the top. The concreting is generally performed with Tremie method of concrete piling.

There are normally 6 types of cast in situ piles as below:-

1. Simplex Pile, 2. Franki Pile, 3. Vibro Pile, 4. Vibro Expanded Pile, 5. Raymond Pile, 6. Mac Arthur Pedestal Pipe

Benefits of Cast In Situ Concrete Piles: The cast in situ piles are set up with pre-excavation and reduce the vibration because of driving as in case of driven piles.

In housing area, sound pollution may occur if the piles are entered by hammering. To get rid of this issue, situ piling is suitable in such areas.

For water logged area, cast in situ piling with permanent casing is very effective.

The skin friction resistance with the ground is fully used in cast in situ piles throughout the design phases that is not recommended in case of driven piles where only the end bearing is applied.

Normally, there is no need of any foreign materials and tools and the original equipments and materials will meet the requirements of a project, as a result the cast-in-situ piles become as a cost-effective and adjustable type of pile foundation.

Precast piles should be designed to satisfy the handling and driving stresses thus enhancing the essential reinforcement that does not happen in the case of cast in situ piles and therefore, the amount of necessary reinforcement is minimized.

Cast in situ piles are attached over the ground with a pile cap that applies a monolithic approach. The top ground is excavated up to pile cut off level from where the slushy low quality concrete is eliminated with hand hilty to retain developed rebars into the pile cap.

Because of this monolithic connection, cast in situ pile provides good resistance against the earthquake and wind forces.

As soon as the piles are casted, no maintenance is required.

Since the materials and machinery applied are obtained from the local community, local contractors can perform the job and not any skilled labor is required for cast in situ piles.

No serious consideration should be provided for joints in cast in situ piles with regards to precast driven piles.



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How concrete is mixed in different ways

Concrete belongs to a composite material formed by cement, sand, coarse aggregate, water and chemical admixtures (if necessary). To maintain the superior quality of concrete, the materials of the concrete should be blended properly so that the quality of concrete is not impacted.

A well-mixed concrete is formed on the basis of the following conditions:

• The color of the concrete should be consistent.
• Admixture of all concrete materials like cement, fine aggregate, coarse aggregate and water should be uniform.
• Cement paste should wrap all the surface of the aggregate.
• Segregation should not happen as soon as the mixing of concrete is completed.

Mixing concrete is dependent on the following three options:

• Hand mixing (Mixing concrete devoid of a mixer)
• Machine mixing (Mixing concrete with a mixer)
• Ready mix concrete

Hand mixing (Mixing Concrete without a Mixer): Hand mixing stands for the method of mixing the different materials of concrete by hand. Mixing concrete devoid of a mixer is suitable for small works. Mixing of materials is executed on masonry platform or flat iron sheet plates.

The hand mixing concrete is performed as follow:

• Expand the measured quantity of sand on the platform, and then unload the cement on the sand.
• The sand and cement should be blended thoroughly with the help of shovels in the dry state.
• The measured amount of coarse aggregate should be extended, and the mixture of sand & cement should spread on it and mixed in an exact manner.
• Depression is provided at the centre of the mixed materials.

• Include 75% of the required quantity of water in the depression and blend well by the shovels.
• Include the leftover amount of water and the mixing method should be carried on unless a uniform colour and consistency of concrete is procured. Time of mixing concrete should not be in excess of 3 minutes.
• The mixing platform should be washed at the end of the day’s work.

Machine Mixing (Mixing Concrete with a Mixer): Machine mixing is mostly suitable for bigger projects where huge masses of concrete are necessary. The machine mixing can retain the persistent uniformity of concrete. Besides, the machine mixing can significantly reduce the mixing time. In recent times, different types of concrete mixers are available which run with petrol/diesel or electricity.

The machine mixing is performed in the following ways:

• Initially, the concrete mixer should be drenched inside of the drum.
• After that Cement, sand and coarse aggregate should be arranged in the portable concrete mixer in desired ratio.
• The dry materials should be blended in the mixing machine. After this, exact quantity of water should be added slowly when the machine is running.
• The concrete should be blended for minimum two minutes after placing all materials in the drum.
• If segregation occurs, the concrete should be remixed after unloading from the mixer.

Ready Mix Concrete: Ready Mixed Concrete (RMC) is developed in the factory or in a batching plant and supplied in a ready-to-use manner. The quality of the consequential concrete is superior as compared to the site-mixed concrete.

Less time is necessary for ready mix concrete as compared to site mixing (hand or machine mixing) and quality of concrete is also greater than the site mixing.

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Rajib Dey

www.constructioncost.co

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The role of water in concrete

Water Cement Ratio signifies the ratio among the weight of water to the weight of cement applied in concrete mix.

Generally, water cement ratio remains under 0.4 to 0.6 with adherence to IS Code 10262 (2009) for nominal mix (M10, M15 …. M25)

The strength of concrete is directly impacted by the water cement ratio. It enhances the strength if employed in perfect ratio and if the ratio is improper, the strength will be reduced.

The importance of Water in Concrete

Concrete refers to a macro content. It comprises of micro constituents like cement, sand, fine aggregate & Coarse aggregate. With the purpose of obtaining high strength concrete to resist the desired compressive strength, it is required to set exact ratio of admixture to unite these materials.

The role of water is important here to accelerate this chemical process by adding 23%-25% of the cement volume. It produces 15% of water cement paste also called gel to fill the voids in the concrete.

Impact of too much water in concrete: If additional water is added more than the permissible limit of 23%, the strength of concrete will be significantly affected.

If the task of adding water is continued to improve the workability then the concrete contains lots of fluid materials where the aggregates will settle down. As soon as the water is evaporated it puts down lots of voids in concrete which influences the concrete strength.

But if the guidelines are followed to retain the strength of the concrete then it will change the concrete workability and makes it difficult to manage and place them.

Workability signifies the capacity of concrete to manage, convey and place devoid of any segregation. The concrete becomes perfectly workable if it can be easily dealt with, placed and transported devoid of any segregation at the time of being placed in construction site.

For this purpose, plasticisers & superplasticizers are utilized to enhance the workability by keeping the W/C Ratio unchanged.

In order to know how to work out water cement ratio, go through the following construction article www.civilology.com

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www.constructioncost.co
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Guidelines for reinforced cement concrete design

This construction video provides detailed guidelines for designing reinforced cement concrete with adherence to the Indian National Building Code (IS 456 – 2000).

This code is designed for general structural application of plain and reinforced concrete. This code employs the limit state design approach along with working stress design approach. It provides wide-ranging information on the different characteristics of concrete.

It comprises of the following five sections and eight annexures:

• Section 1: General
• Section 2: Materials, Workmanship, Inspection and Testing
• Section 3: General Design Considerations
Section 4: Special Design Requirements for Structural Members and Systems
• Section 5: Structural Design (Limit State Method)

By going through this video, you will learn how to design various types of structural components like beam, column, slab, footing etc. as well as objective of structural designing.

The video briefly explains the following topics :-

1. Purpose of structural designing and designing method
2. Variation among plain concrete and reinforced concrete
3. Fundamental characteristics of concrete as follow
a. Grade of concrete
b. Characteristics strength of concrete
c. Modulus of elasticity of concrete

d. Creep and shrinkage
e. Longevity
f. Tensile strength
4. Fundamental properties and categories of reinforced steel
a. Grade and categories of steel
b. Yield strength of mild steel and HYSD Bars

Watch the following video for online demonstration.

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Published By
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www.constructioncost.co

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How the functionality of concrete is affected by the different factors

Quantity of water

Size aggregates

Grading of aggregate

Shape of aggregate

Texture of aggregate

Ratio of concrete

QUANTITY OF WATER.

Water is considered as the most vital factor that can influence the functionality of concrete. If more water is added, the functionality of the concrete will be enhanced. But with the inclusion of too much water, the durability of concrete can be reduced.

SIZE OF AGGREGATES

If the size of the aggregate is increased, the functionality of the high strength concrete will be reduced whereas the functionality of normal strength concrete is raised with the increment in the size of the aggregates.

GRADING OF AGGREGATES

If the grading of the aggregates is superior, the strength of the concrete along with the functionality is enhanced. The functionality of the concrete becomes superior with least number of voids. As for example, if there are 5%viods, the strength of the concrete will be reduced by 30 percent.

SHAPE OF AGGREGATE

The functionality of concrete is influenced by the shape of aggregate. The cubic shaped aggregate is mostly recommended. The functionality of the concrete is greatly affected by the stretched and odd shaped aggregate. The longevity of such concrete is also decreased. The functionality of the concrete is increased if the concrete contains rounded aggregates. But in this situation, the bond of the concrete remains extremely weak.

TEXTURE OF CONCRETE

Texture of aggregate is another crucial factor to influence the functionality of concrete. In order to develop a concrete, porous aggregate needs more water and thus the functionality of concrete is reduced.

RATIO OF CONCRETE

The functionality of concrete is also influenced by the ratio of fine aggregates and the course aggregate. If the number of fine aggregates in concrete is increased, the functionality of the concrete becomes superior. As for example, if the quantity of the cement is increased, the functionality of the concrete enhances.

To read the complete article, go through the following link

www.civiltechnology.org

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Rajib Dey

www.constructioncost.co

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ADAPT-Builder Suite – A useful construction software for designing conventionally reinforced concrete structures

ADAPT Corporation has developed ADAPT-Builder Suite that is used to make complete analysis of concrete buildings. This construction program is useful for General Structural Analysis, Analysis of Plates, Analysis of Frames, Analysis of Beams, Concrete Design, Analysis of Columns, Wind Loading, Foundations.

It contains Edge, Floor Pro and MAT etc. Edge makes analysis of complete building model for lateral and gravity load. Floor Pro is applied to make the comprehensive design of any concrete floor system with or without post-tensioning. MAT is used for producing the innovative design of foundations. There is also an optional column design module that provides support with a well-organized workflow for creating the cohesive design of vertical elements in a structure.

A robust and easily adoptable 3D finite element engine makes the Builder an exceptional construction software to perform the modeling and analysis of any concrete building efficiently.

Builder’s modules are compatible with an extensive range of international codes. Besides, they are well suited with simplified BIM workflows and can be easily incorporated with Revit Structure and other structural analysis packages.

To get more information, visit 

www.adaptsoft.com

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Rajib Dey

www.constructioncost.co

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Designers Ron Culver & Joseph Sarafian Jointly Develop An Exclusive Method To Cast Concrete In Lycra Stretched With Robotic Arms

Both the designers Ron Culver and Joseph Sarafian have discovered a unique system for casting concrete in Lycra stretched with robotic arms. This newest method can be applied to develop basic new architectural forms (+ movie).

The Fabric Forms project comprises pouring a concrete fibreglass mixture into Y-shaped Lycra sleeves stretched into position through six-axis robots.

This casting system can be implemented at different scales in the construction jobsite in near future. It can be expanded to form unique building facade elements as well as the primary structure of a building.

With its simple production capacity, the fabric facilitates the users to generate various shapes devoid of casting a unique mould each time they create a new shape.

Fabric Forms facilitate to produce compound curvature beyond a cast object that would otherwise be lost once rigid formwork is eliminated.

It is considered as a more endurable substitute that can minimize labor and material costs. It is more rapid process as compared to conventional construction methods.

Conventional casting methods are both laborious and unsupportable as plywood formwork is frequently exposed and casted off as soon as concrete has cured.

When the concrete is set, the fabric is then exposed that leads to marginal waste. The pieces will require roughly 45 minutes to solidify and are set collectively through a 3D-printed coupler for generating larger assemblies that could be later on utilized as attractive facades or even load-bearing structures.

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Published By

Rajib Dey

www.constructioncost.co

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FrameDesign – An Exclusive Construction App For 2D Frames Design

LetsConstruct developed FrameDesign. It is an exclusive finite element app and specifically designed for civil engineers, mechanical engineers, architects and students to simplify designing process for 2D frames. It is still in the beta testing phase.

This useful construction app facilitates the users to input and edit hyper static structures, forces, supports etc both graphically and textually as well as make calculation instantly.

FrameDesign contains the following features :

F, T and q (rectangular and triangular) loads

Fixed and hinge connections at beam ends

Moment, Shear, Stress, Deflection, Reaction forces and Unity checks

Imposed deflections

M, N, V, ux, uz, utot, phi, sigma and unity checks output

Fixed, hinge and roller supports in any direction

Load cases and load combinations, including safety factors

Profile groups; each group can have its own color

Import any steel profile or general section from our free Engineering Libraries (EU, UK, AU, US & CA profiles)

Import dxf files

Export to our Concrete Design and Steel Design apps

Share picture

Snap points

Undo function

Annotations

Formulas

Multi copy

Scale entire structure

Trim/extend

Automatic dimension lines (Autocad look)

Element and node numbers

Both graphical and textual edit modes

Metric & Imperial units

Multitouch zoom (pinch zooming)

Many options for showing/hiding items

Options to set almost all colors in the app

Dark and light theme

Available in 10 Languages

Save your structures in the cloud (CloudConstruct)

Built-in simple scientific calculator

Wobbly effect

The users can download a web version of FrameDesign by going through this link.

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Rajib Dey

www.constructioncost.co

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Categories, Design And Modes Of Failure Of Retaining Walls

Retaining wall is described as a fairly hard wall. It is constructed to give support to the soil mass horizontally to hold the soil at various levels on the two sides.

The following topics are covered in this construction article :-

• Types

• Design

• Modes of Failure

Types of retaining wall:

Usually the retaining walls are categorized as follow :-

Gravity Retaining Wall: Here weight is the key factors for these walls to maintain durability. In general, the walls are developed with plain concrete or masonry. For the structures having long height, these walls may be quite expensive.

Semi-gravity Retaining Wall: The section size regarding a gravity retaining wall is decreased with the placement of the fewer amount of adjacent to the back face. Such walls can be termed as semi-gravity walls.

Cantilever Retaining Wall: The Cantilever retaining walls are mainly developed with reinforced cement concrete. The wall comprises of a lean stem together with a base slab cast monolithically. For the construction that contains a height of 6 to 8 m, this type of wall is cost-effective.

Counterfort Retaining Wall: In Counterfort Retaining walls, there are lean vertical slabs alias counterforts which are positioned over the vertical steam recurrently. The counterforts join the vertical stem by the base slab. Hence, the vertical stem and the base slab extend amid counterforts. Here the counterforts are used to reduce the shear force and bending moments in the vertical stem and the base slab. The structures which contain a height over 6 to 8 m, the counterfort retaining walls are economical.

Guidelines for designing retaining walls: Before developing the realistic design, the soil parameters which can impact the earth pressure and the bearing capacity of the soil, must be analyzed properly. The soil parameters contain the unit weight of the soil, the angle of shearing resistance, the cohesion intercept and the angle of wall friction. The soil parameters are liable for detecting the lateral earth pressures and the bearing capacity of the soil. As soon as the earth pressures are detected, the retaining walls should be verified completely to find out the strength toward sliding, overturning, bearing capacity failure & tension.

Other modes of failure of retaining walls

Besides, three types of failures like sliding, overturning and bearing failure, the following two modes are also liable for collapsing of a retaining wall in case the soil below is feeble.

Shallow Shear Failure: This type of failure takes place along a cylindrical passing with the heel of the retaining wall owing to the extreme shear stresses along the cylindrical surface inside the soil mass. Usually the cause for safety alongside horizontal sliding is reduced contrary to the shallow shear failure. Due to this, if the factor of safety alongside sliding exceeds by 1.5, shallow shear failure will not occur.

Deep shear failure: It happens along a cylindrical surface, if there exists a feeble layer of soil below the wall a depth regarding 1.5 times the height of the wall. The trial and error processes are applied to ascertain the critical failure surface.

Ref : www.civileblog.com

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Published By

Rajib Dey

www.constructioncost.co

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How to compute the design moment strength of a singly reinforced concrete beam

This construction video is made on Reinforced Concrete Design and it narrates the method for creating the estimate of the design moment strength concerning a singly reinforced concrete beam following the ACI Code.

The video highlights the following :-

The video highlights the following :-

i) How to draw the strain and stress profile at ultimate

ii) Force equilibrium to estimate neutral axis depth

iii) Examine assumptions (i.e. verifying steel yield) and decide phi

iv) Compute nominal moment and design moment

Go through this supportive article to learn more

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Published By

Rajib Dey

www.constructioncost.co

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