Questions tagged [reinforced-concrete]
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89 questions
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Find out the loads acting per unit length on the beams supporting an open well stair
Please see the attached picture.
I want to find out the dead load per unit length and live load per unit length (both in kN/m), that will be acting on the floor beam (300 mm × 450 mm) and the landing ...
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Normal Weight of RC Beam
Is 450kg/m for a reinforced concrete beam outlandish?
The dimensions are:
width: 0.3m
depth: 0.6m
I am designing a beam, and that is what I got.
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How to build apartment floors/ceilings to not transfer sound?
How do new apartment buildings build their floors/ceilings to prevent the transfer of sound between people living above/below each other?
Note: I'm not asking about how to soundproof an existing ...
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USD beam to support ultimate moment of 650kN-m, limited to an effective depth of 600mm and 300mm width. Effective depth for compression steel is 60mm
I don't understand how exactly can a beam as described can support a 650kN-m ultimate moment. The only allowed bars are 28mm∅ bars. Consider 40mm side covering and bar spacing to be greater or equal ...
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In a pre stressed concrete? Why is the top fiber considered as under compressive stress?
I have been solving problems involving pre stress concrete, i want to clarify why is the top fiber always considered as under compressive force, in my understanding the concrete would bend positively ...
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RC Design Design of foundation to resist uplift to eurocode 2 example clarification
recently I acquired the following book
"Reinforced Concrete Design: To Eurocode 2, Book by J. H. Bungey, R. Hulse, and William Henry Mosley"
In chapter 2 example 2 the following question was ...
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How to design safely collapsing buildings?
Background—Currently, buildings seem to be designed to be strong enough to not fall upon dangerous events, such as earthquakes. This makes them expensive, and out of the reach of poor places.
Poor ...
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Bending moment capacity of T-cross-section (reinforced concrete)
I have a question regarding a simplification/derivation of the (ULS) bending moment capacity of a given T-cross-section, with compression-zone on the flanged side. The problem is that the rebar-strain ...
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Can bars made out of PET be used to reinforce concrete?
I watched a video, in which a man shows how to make something that looks like a rebar out of PET bottle strips.
This made me wonder: can something like this be used to reinforce concrete when ...
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Can a nuclear reactor withstand a missile attack?
Because of the war in Ukraine I am interested in the question if a nuclear reactor is designed to withstand a missile attack.
In university, back in the eighties, we were assured that a nuclear ...
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How to calculate the available anchorage length in reinforce concrete design?
Hello everyone I am taking a course on RC this semester and I am kinda bumped out by all of the terminology here.
The main question I have is what is the difference between anchorage length and ...
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What does$ Ast = N16 @ 175mm $centres means in designing reinforced concrete?
I have the following problem, which I already know the general steps into solving.
My general approach is: calculate I cracked as we are already told that the section is cracked, and then finally use ...
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TMT Steel in layers
The Site Engineer and I were arguing about the placement of the reinforcement bars in layers. The Steel technician (TMT) placed the third layer of reinforcement in the 2nd layer. I said it didn't ...
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what is the minimum number of reinforcement bars in a circular tie rod?
I know that the minimum number of reinforcement bars in circular concrete section of columns are 6, is it the same for circular tie rod section?
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What is the cause of this cracking pattern in a simply supported beam?
Background
On May 5th 2022, a bridge was struck in Brantford, Ontario, Canada by a commercial vehicle. This vehicle struck a reinforced concrete protection beam placed on the on-coming side for the ...
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Beam rebar doesn't develop its length in column. Reinforced concrete analysis and design
In reinforced concrete design, there are some cases that engineers have to design beams which rebar doesn't develop its complete length or hook length according to codes. It is because of restrictions ...
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How thick must a concrete or block wall be to withstand hydrostatic pressures up to three meters' height?
I'm planning a basement 3.6m depth, ~0.5m of which extended above ground surface level, in a deep clay/alluvial terrain (bedrock inaccessible). Torrential rainfall during rainy season saturates the ...
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Why the model with rebar layer shows one sided plastic strain in Abaqus?
Using the damaged plasticity model, I modeled a concrete coupled shear wall in Abaqus, once with discrete rebar and once with rebar layers for the slab. I used the general static solver to run the ...
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Pouring large circular footing in segments
Lets say we have a very large and deep circular footing for a tall tower such as an industrial chimney or a wind turbine, and for convenience we want to pour it not at once but in sections. Can this ...
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Jointed reinforced concrete tie-bar smoothness
We know that in Jointed Reinforced Concrete pavements we use dowels and tie bars. Why are dowel bars Smooth and tie bars are deformed? Dowels are used to transfer about 40% of the load from one slab ...
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Do PVC concrete joint water stops degrade over time? Or were they never installed correctly?
A UK subterranean reinforced concrete structure built in the late 1960s has experienced sustained water ingress over time as shown by the deposition of minerals of the walls:
According to the ...
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What is a 'rocker slab'?
See below for an extract from a general arrangement drawing from the 1980s. It makes reference to a '9" rocker slab' which appears to be a slab supported by steel beams.
Does anyone have any ...
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Turndown for a Post-Tension Concrete Court
my father has a sports court construction business and I work with him infield and in the office. He usually almost always builds the sports courts using post-tension concrete with 4000 PSI concrete. ...
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How do hooks/bends cause bearing stresses in reinforced concrete?
Can someone please explain the exact mechanics of development of bearing stresses in concrete on account of bending of steel reinforcement and/or providing of hooks at the beam-column junction for ...
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Can anyone help me with the concept of bearing stresses in steel reinforcement in Reinforced Concrete?
When there is tension reinforcement(steel) embedded in concrete, does it not also undergo bearing stresses on account of the weight of the concrete and other forces which are acting above the steel? ...
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What is this circular metal object embedded in spalled concrete?
Consider the piece of spalled concrete shown in the attached image. It has spalled due to the corrosion of the reinforcement bar. There is a small circular piece of metal embedded within the spalled ...
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Concrete rebar cover requirements - Hook lift anchors
ACI 318 7.7 covers requirements for cover when designing rebar placement within concrete. However, they are for general components and makes no exceptions for small irregularities such as lifting hook ...
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Is it possible to measure the concrete workability by a mobile app one day? [closed]
After studying all methods that can measure the concrete slump, I found 62 devices that service this purpose at the same time these devices are expensive and not practical enough, for this reason the ...
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Concrete pad over filled, in-ground pool better with or without wall support?
We are currently having a project done in our backyard to: (1) fill an in-ground pool and (2) build a "sport court" (with a large concrete pad and some tiles) over top.
The pool demolition ...
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Conservative rebar dowel hole sizing and embedment depth
My question concerns the hole sizing and embedment depth of post installed rebar which is secured with epoxy mortar into a hole in a reinforced concrete slab.
Hole diameter sizing
My assumption #1 ...
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Concept design for an extension to a blanket raft slab
A blanket raft is a type of solid slab raft consisting of deeper ‘toe’ sections running around the edge of the foundation as well as a central deeper ‘beam-like’ section which offer rigidity to the ...
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In a reinforced concrete detail drawing what does 'reinforcement to be GK 60' mean?
Consider the following extract from a British reinforced concrete drawing from 1970:
It states that 'REINFORCEMENT TO BE G.K 60. UNLESS STATED OTHERWISE'
What is the meaning of GK 60? What property ...
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Why is there a row of circular holes in this concrete beam?
The reinforced concrete beam (approximate dimensions 36" x 18") shown in the image below has a row of circular holes at 3/5ths of the height of the cross-section at approximately 300 mm centres.
My ...
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Is it safe to slightly cut the edge of RCC column for passage of pipe in bathroom?
The RCC column was cut in my absence due to passage of pipe for bathroom fittings. The thickness is about 1.5 in. Will it hamper the stability of structure?
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Why do we use the strain-controlled test for the compressive strength of concrete?
As you all now, a typical stress-strain curve for concrete under compression can be seen in any reinforced concrete design textbook. The decreasing part of the curve (post-peak) can be obtained by ...
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The design of precast concrete-- are they the same with cast-in situ design?
I am curious as to how different is precast concrete design than conventional cast-in situ reinforced concrete design as far as structural engineering is concerned.
To my mind, they should be the ...
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Are the design load values in this floor determination table (span chart) inclusive or exclusive of the given floor weight (inherent dead load)?
So, I have been doing research into the use of Insulated Composite Concrete Forms (ICCFs) for small-scale construction, and that has led me to looking at the Rastra ICCF system, as it has been in ...
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Maximum allowable crack in Post Tension concrete
What is the maximum allowable crack size dimension in a post-tension concrete slab before it is considered a "structural" crack, in Arizona, USA? Is there a certain standard for this. I have tried ...
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Dependency between load capacity for reinforced concrete slab and thickness
How does the load capacity for a reinforced concrete slab depend on the thickness of the slab?
Example:
Let's suppose that we have the following constants:
concrete quality (including the maximum ...
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Why not a reverse bending in the slab?
When I'm looking at images / videos about the load supported by reinforced concrete slabs, I always see a compression at the top of the slab in every point that varies from the center to the edges:
...
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Reinforced mesh at different distance in a concrete slab?
Trying to determine some information regarding the reinforced concrete slabs (reinforced with mesh) in an apartment, by looking through the holes in the middle of the rooms for lights, I've come ...
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Does screed increase the slab tension capacity?
Does a screed applied over the slab increase the slab tension capacity?
Somehow it's counter intuitive because adding weight on the slab should tension it, but do the slab and the screed behave as a ...
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Impact of having flexible electrical hose buried into the reinforced concrete slab
Given:
a reinforced concrete two-way slab at about 160 mm (the edges are cantilevered between the concrete walls)
the electricians buried the flexible electrical hose into the slab (red lines in the ...
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How do i find the effective length factor (k) for a column from this chart?
I need to find the effective length of a column (kl) from this chart which can be found in the "design of concrete structure" By Dr. Arthur Nilson.
the question states "if Psi top is 1.5 and the ...
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Finding good and effective solution for overhead RCC slab spalling due to corrosion in Rebars [closed]
Please suggest some effective repair solution for spalling overhead slab due to high corrosion in rebars.
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Using electricity to heat up a slab through post-tension cables?
Would a passive and controlled amount of electricity fed through post-tension cables, heat up a slab, without ruining the dependability and health of the post-tension cables, and the concrete itself?
...
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How to perform SLS check with strut-and-tie method?
I am using strut-and-tie method to design a corbel. I noticed that Eurocode mentions strut-and-tie only in section 6, which is ultimate limit state design. How do I perform serviceability limit state ...
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Analysis method for two-way slab floor with central column
What method would be appropriate to analyze this concrete structure?
A two-way rectangular concrete slab with walls and central column.
I would like to understand how to model it with either yield ...
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Percentage area of steel for a retaining wall - standard formula doesn't make sense to me?
I'm looking at the usual UK/EU standards formula for the reinforcing steel area percentage, in a retaining wall. Essentially in "usual" cases it comes down to 0.13% of the cross-sectional area of Tw (...
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How to find resisting moment with rebars of different yield strengths?
When designing a concrete slab or rectangular beam, how would you compute the Mn value if there were two rows of rebars one with a yield strenght of 40 ksi and the other with the yield strenght at 60 ...
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