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Civil Engineering
Civil Engineering is a profession of designing and executing structural works that serve the general public, like houses, buildings, roads, etc. A Civil Engineer is an engineer trained in the design and construction of public works, such as bridges or dams, and other large facilities.
4,921 Questions
Why it is undesirable to design over reinforced sections?
1. In over reinforced section failure happens due to concrete which is sudden without any type of warning like bending or deflection....
2. Steel is one of the most costly material used in construction work so from the economical view it is also undesirable to provide over reinforced section...
How does the fineness modulus of aggregates affect the strength of concrete?
how does the fineness modulus of aggregate affect the strength of concrete
800 plf x 15 = 12000 pounds total weight
each end sees 1/2 or 6000 pounds shear
B
Dampers are used to regulate the flow of air or gasses in ductwork and chimneys.
Without dampers the flow in ducts would only be regulated by the fan speed, the flow in chimneys would be dependent on the developed draft, and neither would be controllable directly.
What is the TMT 550 grade steel lap length?
Lap Length is the length overlap of two rebars tied to extend the reinforcement length. Lap Length of about 50 times the diameter of the bar is considered safe. Let us understand the term “lap length” with an example: suppose there is a need to build a 200ft tall structure, say column. We know that for convenience of transportation, standard length manufactured are upto 12 metre only, hence to strengthen the structure overlapping of two or more bars are done side by side upto the design length. Reason for doing so is the required tension forces that is needed to transferred from one bar to the other. So if diameter of tmt is A then lap length will be 50A. If both diameter is same.
Now coming to question, lap length of tmt 550 grade is usually done where minimum bending stress is encountered. We at Shree Ji Steel offer wide range of sizes and grade for various product range which can be checked from our website Shree Ji Steel Corporation.
Who is making cement civil engineers or chemical engineers?
If your asking who does the mix design for cement or concrete that would normally be done by civil/construction engineers. The chemical engineers may play a roll if they are creating a new additive to make the cement or concrete dry faster while retaining or improving its design strength.
What is the meaning of steel re bar?
Rebar is an informal term for steel "reinforcing bar". These are steel bars that are placed within the structure before the wet concrete is placed. Steel reinforcement is necessary for almost all structural concrete because concrete has virtually no tensile or shear strength. The rebar provides almost all of the resistance to tension and shear within the structure.
How do you calculate invert level of existing pipe?
The invert level of an existing pipe is the result when you subtract the depth/height of the lowest elevation/level of the inside/inner portion of the existing pipe from the surface reference elevation most commonly known as benchmark (BM). Benchmark (BM) can usually be found on permanent structure in the surface/ground.
Why shear stresses are maximum at neutral axis?
according to bending stress because shear stress at neutral is 0 that is why shear force is maximum
What is the standard height for urinal sensors with connection?
Standard height for urinal sensors should be 1450mm centre from floor level
How do you convert cylinder strength to cube strength?
With regards to concrete strength, a cylinder test strength is usually between 5 and 25 percent less than a cube test strength. You can also try using this equation: fbk=(fck-1.77)/0.83 where fbk is cubic concrete strength and fck is cylindrical strength.
Why cement been used as concrete mixing materials?
cement used in concrete because it gives the strenth to the str
What is negative slip in a reciprocating pump?
when actual flow(Qact) in pump is greater than theoretical flow (Qth) then negative slip occurs....
Which process removal of colloidal matters from water?
1) Simple and cost effective, Flocculation >>the right type of flocculant used,follow by sedimentation then pass through a sand filter.
2)Untrafiltration
It is all about the arch. Throughout the history of building people figured out that an arch is the strongest form of support for a doorway or tunnel. The reason is that any weight on the arch is all directed to the middle so that the entire arch is helping to support the weight. If you have a straight line roof, weight at the center is supported only at the area that is in contact with the weight.
What is the mixing ratio in asphalt concrete?
Aggregate is the granular material used in asphalt concrete mixtures which make up 90-95 percent of the mixture weight and provides most of the load bearing characteristics of the mix. Therefore, the quality and physical properties of the aggregates are critical to the pavement performance. The following is recommended:
- (1) Aggregates should be nonplastic. The presence of clay fines in an asphalt mix can result in problems with volume swell and adhesion of asphalt to the rock contributing to stripping problems. The minus #4 sieve material should have a minimum sand equivalent value of 45 using the test method described in the American Association of State Highway and Transportation Officials (AASHTO) specification (AASHTO T-176).
- (2) A limit should be placed on the amounts of deleterious materials permitted in the aggregates. Specifications should limit clay lumps and friable particles to a maximum of one percent.
- (3) Durability or weathering resistance should be determined by sulfate soundness testing. Specifications should require a sodium or magnesium sulfate test using the limits described in the AASHTO specification M-29.
- (4) Aggregate resistance to abrasion should be determined. Specifications should require a Los Angeles abrasion loss of 45 percent or less (AASHTO T-96).
- (5) Friction between aggregate particles is dependent on aggregate surface roughness and area of contact. As surface friction increases, so does resistance of the mix to deformation. Specifications should require at least 60 percent of the plus #4 sieve material to have at least two mechanically induced fractured faces.
- (6) The quality of natural sand varies considerably from one location to another. Since most natural sands are rounded and often contain a high percentage of undesirable materials, the amount of natural sand as a general rule should be limited to 15 to 20 percent for high volume pavements and 20 to 25 percent for medium and low volume pavements. These percentages may increase or decrease depending on quality of the natural sand and the types of traffic to which the pavement will be subjected.
- (7) For adequate control, aggregate gradations should be specified from the maximum particle size to the #200 sieve so each successive sieve opening is about 1/2 the previous sieve opening (for example, 1 inch, 1/2 inch, #4, #8, #16, #30, #50, #100, #200). The only accurate method to determine the amount of minus #200 sieve material is to perform a wash gradation in accordance with AASHTO T-27 and AASHTO T-11.
- (8) The ratio of dust (minus #200 sieve material) to asphalt cement, by mass, is critical. Asphalt concrete mixes should require a maximum dust asphalt ratio of 1.2 and a minimum of 0.6.
- (9) A tool which is very useful in evaluating aggregate gradations is the 0.45 power gradation chart. All mixes should be plotted on these charts as part of the mix design process (Attachment 1).
(10) An aggregate's specific gravity and absorption characteristics are extremely important in proportioning and controlling the mixture. It is recommended that AASHTO T-209 be used to determine the maximum specific gravity of asphalt concrete mixes. States not using AASHTO T-209 should be aware of the difficulty of determining the theoretical maximum density using individual ingredient specific gravities and their percentages in the mixture. These difficulties will result in inaccuracies in determining the specific gravity of the mixture. These inaccuracies will carry through to the calculation of the densities in the compacted mat and may result in improperly compacted pavements. It is also necessary to determine the bulk dry specific gravity of the aggregate in order to determine the voids in the mineral aggregate (VMA).
The target value for VMA should be obtained through the proper distribution of aggregate gradation to provide adequate asphalt film thickness on each particle and accommodate the design air void system. In addition, tolerance used in construction quality control should be such that the mix designed is actually produced in the field.
What is the meaning of cement concrete of grade-m150?
the M150 grade concrete is today's hardest concrete and it has a optimal water composition of 0.18 to 0.28 percent . there is no composition for this concrete it is derived through experiments . used in very heavy structures . it has not used in india .
What is Need of engineering drawing for civil engineering?
Engineering drawing shows the proper map of building which helps in deriving the estimation cost of building and also help in planning of construction.
