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Student Corner

Why is Revit Getting Popular Among Civil Engineers?

Introduction
Architects widely use Revit for a number of reasons, but nowadays, it is gaining traction among civil engineers too. Civil Engineers widely adopt AUTOCAD to make plans for buildings, design for water tanks, and many more. Nowadays, this software is getting replaced by Revit as it offers 3D rendering quite quickly compared to AUTOCAD. Some additional blocks are also there in Revit that can be imported as plugins which are quite beneficial to place on the drawings without consuming much time.

Both AUTOCAD and Revit are the products of Autodesk, and they share many similarities despite having many differences. One of the main reasons Revit has become so popular is that it was built with the BIM process in mind, and it also works with cloud computing. This allows everyone participating in the project to get their hands on any information they need.

A number of AEC companies request employers with a Revit certification course in order to help users learn about the BIM process to improve their Revit knowledge. Because Revit allows for the production of 3D models, it aids sales and marketing teams in explaining a project’s potential to buyers. Analyzing these models, which give architectural sketches and blueprints, may assist in maintenance planning. Customers can study a virtual design of these models, which works as a sales pitch. Like this, they can have a rough idea of what the structure is going to be.

Revit user interface
Fig 1: Revit user interface
Courtesy: Archdaily

Some of the benefits of Revit are-

  • Labor-saving – All of the data used to create a Revit model is stored in a single database. This means that whenever a person modifies the model, the database is updated. The changes occur throughout the entire model, enabling automation and making the building design more efficient. It eliminates some of the rework that comes with changing the different project files.
  • Cooperation – Revit provides a number of valuable tools for cooperation between file types, disciplines, models, and industries. It combines models as part of the architecture design process or gathers reviews from the users. Revit tools permit users to monitor changes in a linked model, review reporting of those changes, copy items from a coupled model into their basic model, and communicate them to other teams working on the same project requiring resolution.
  • Alliance –The ability of several applicants to work simultaneously in the same Revit model is one of the differences between Revit and AutoCAD compared to AUTOCAD, where only one user can change a .dwg file at a time. Using Revit’s ‘Sync with Central’ tool, users can switch their model changes to a model ‘Central’ while at the same time drawing any changes made by their peer in their local copy of the model from that same ‘Central’ model. The project team will be able to collaborate fully due to this approach, and hence a work balance will be maintained.
  • 2D house plan in Revit
    Fig 2: 2D house plan in Revit
    Courtesy: Revit drawing

  • 3D Rendering – In the design industry, using various pieces of software for rendering and presenting materials is a traditional practice. Even so, Revit delivers all of the tools needed to produce these materials in one place. 3D modeling packages like 3ds Max are helpful for specific industries, such as animation. Creating 3D drawings and renders immediately in Revit, rather than importing a model into another piece of software, saves a lot of time. Revit’s rich material libraries and rendering plug-ins can create 2D presentations and 3D visualization outputs.
  • Cloud-dependent access – Due to Covid, the remote work style is increasing day by day. Revit has enabled model storage in the cloud that can be accessed at any time and from any location. Revit is compatible with a number of cloud-based platforms. Still, the most obvious is Autodesk’s BIM 360 platform, which acts as a “cloud server” where users can save their models, push changes to said models, mark up models and sheets, communicate with team members, and even assist with facility management after construction is completed – all through a web browser. This cloud connection enhances Revit’s power and collaborative capabilities, making it the favorite software among civil engineers.
  • Parametric Modelling – In the Revit BIM software, each component that a civil engineer constructs have parametric properties. This implies that the drawing parts are 3D, but we may change the 3D model by modifying the accompanying 2D planes. The key is that all of the data required to create the model comes from a single source. That database is updated whenever we modify it. It also doesn’t matter where we alter the model, as whatever new data we add is incorporated into the model. This dynamic alteration saves civil engineers a lot of time, and this won’t have any conflicts when trying to match the information across multiple designs.

Conclusion
In order to work in Revit, it is recommended to take up a short-term professional course as the user interface of Revit is a bit complex. It takes up more space in a drive, and so to work with such software, it is highly recommended to use a graphics card on a laptop or desktop. Like Revit, another software that is gaining traction is Sketch Up due to its ability to build up blocks in the drawings without creating them. Moreover, Revit is shadowing AUTOCAD, but it can never follow it entirely as Revit lacks the ease of 2D drawings simplifications. The structural details like reinforcements are easier to depict and draw in AUTOCAD than in Revit. However, advancements are being made to ease the design of the structural elements process in Revit.

References
Grey Edge, “How Learning Revit Is Useful For Architects And Civil Engineers?”- https://www.grey-edge.com/blog/how-learning-revit-is-useful-for-architects-and-civil-engineers/
Grey Edge, “Revit Software Uses in Civil Engineering”- https://www.grey-edge.com/blog/revit-software-uses-in-civil-engineering/
Microsol Resources, “Top 10 Benefits of Revit”- https://microsolresources.com/tech-resources/article/10-benefits-of-revit
Archistar Academy, “The Advantages and Disadvantages of Revit”- https://academy.archistar.ai/the-advantages-and-disadvantages-of-revit

VARIOUS TESTING OF CEMENT

Cement we use may go bad during transportation and storage prior to its use in work.We need to test the cement for a good quality and better performance in concrete mixtures. Broadly there are two tests for cement-

  • Field Testing
  • Laboratory Testing

Field Testing
It is generally done when cement is used for small or minor works. Following are the field tests-

  • After opening the bag of cement, we should give a good look, There should not be any visible lumps present in it. Colour of cement should be greenish grey.
  • It should give a smooth and gritty feeling when pinch of cement is feel between the fingers.
  • If we thrust our hand into the cement bag, it must give a cool feeling.There should not be any lumps inside.
  • If we throw some amount of cement into a bucket of water, it should float sometime before sinking.
  • A cube made from a stiff paste of 100gm cement and little water is to be put in a glass plate. The glass plate is taken slowly under water in a bucket. The shape of the cube should not be deformed while taking into water. After 24 hours cube should retain its original shape.

If a sample of cement truly satisfies the above tests we may say that the cement is not bad. But the above tests do not really indicate that the cement is really good for important work or big structure. For using cement in important and major structure, it should satisfy the Indian Standard specifications. It is possible only in laboratory testing to confirm the requirements of specified physical and chemical properties.

Laboratory Tests

Following are the laboratory tests for cement:

(i) Fineness Test
(ii) Setting time Test
(iii) Strength Test
(iv) Soundness Test
(v) Heat of Hydration Test
(vi) Chemical Composition Test

Fineness Test
The fineness of cement has great importance on the rate of hydration and hence rate of gain of strength. Finer cement has greater surface area for hydration and hence strength develops at a faster rate. Fineness of cement is tested in two ways-

  • By sieving
  • By determination of specific surface area.

Sieve Test:
In this test, about 100 gm of cement is taken on 90 micron sieve. Air-lumps are broken down by fingers. The sample is sieved continuously with circular and vertical motion for 15 minutes. The residue left on the sieve is weighed. The value should not exceed 10% for ordinary cement. This test is rarely used now-a-days.

Apparatus for fineness of cement
Fig 1: Apparatus for fineness of cement.
Courtesy: civilalliedgyan.com

Air Permeability Test:
Here fineness of cement is represented by specific surface area(sq cm/gm or ).Fineness of cement is represented by specific surface expressed as total surface area in sq cm/gm of cement. It is also expressed as /kg. Lea and Nurse Air Permeability Apparatus is used in measuring specific surface area of cement. The principle is based on the relation between the flow of air through the cement bed and the surface area of the particles comprising the cement bed.

Fineness can also be measured by Blains Air Permeability Apparatus. This is most commonly used in India. In this method a cement sample of 2cm height is placed on a perforated plate and pressure is applied. The size of perforation is 40.The manometer is connected to the top of the permeability cell and air is turned on. The lower end of the permeability cell is then slowly connected to the other end of the manometer. The rate of flow is so adjusted that the flowmeter shows a pressure difference of 30-50 cm. The reading of manometer is recorded. The process is repeated till the ratio between reading of manometer to pressure difference attains a constant value.

Air Permeability Apparatus
Fig 2: Air Permeability Apparatus

Setting time Test:
During the time of actual construction dealing with cement paste, mortar and concrete should remain in plastic state. Certain time is required for mixing, transporting, placing, compacting and up to finishing. Time interval between the moment that water is added to the cement to the time that the paste starts loosing its plasticity is called initial setting time of cement. Normally a minimum of 30 minutes is given foe mixing and handling operation. Vicat’s Apparatus is used for setting time test. Here 500 gm of cement sample is taken having consistency 0.85P and made a cement paste. The paste shall be gauged and filled into the Vicat’s mould in specified manner within 3-5 min. The square needle to the Vicat’s plunger is attached and lowered it gently to make contact with the surface of the mould and it is quickly released. As the needle penetrates only to a depth of 33-35 mm from the top, the test is completed. The time should not be less than 30 minutes for OPC and 60 minute for low heat cement.

The final setting time is the time elapsed between the moment the water is added to the cement and the time when the paste has completely lost its plasticity and has attained sufficient firmness to resist certain definite pressure. In this test, square needle is replaced by a needle with annular collar. Here the paste should attain such hardness that the needle doesn’t pierce through the paste more than 0.5 mm. The final setting time should not be more than 10 hours.

Vicat’s Apparatus for setting time test
Fig 3: Vicat’s Apparatus for setting time test

Strength Test
The compressive strength of hardened cement is most important of all the properties. In this test 555 gm of standard sand, 185 gms of cement (1:3;ratio of cement to sand) is taken in a tray and mix them with a trowel for 1 minute and water is added of quantity ()% of combined weight of cement and sand. The three ingredients should me mixed thoroughly until the mixture shows uniform colour. The time of mixing should not be less than 3 minutes. Immediately the mortar is filled into a cube mould of size 7.06 cm. The area of the face of the cube will be equal to 50 sq cm. The mortar should be compacted for 2 minutes. The compacted cube should be kept at a temperature of and at least 90% relative humidity for 24 hrs. Three cubes are tested for compressive strength at 1 day, 3 days, 7 days and 28 days where the period of testing being calculated from the completion of vibration. The compressive strength shall be average of strengths of three cubes for each period respectively. The compressive strength of 33 grade OPC at 3 days, 7 days and 28 days is 16 MPa, 22 MPa and 33 MPa respectively. Load applied gradually as 0 to 35 N//min on cubes by using UTM machine.

Soundness Test
Cement after setting should not undergo any appreciable volume change. It causes serious difficulties for the durability of structures. The cement having some quantity of free lime, magnesia and excess sulphates undergoes large change in volume as the time elapses. This test is performed to ensure that the cement does not show any appreciable expansion. The soundness of cement is determined by “Le Chatelier’s method” or by mean of “Autoclave test”.

Le Chatelier’s Apparatus
Fig 4: Le Chatelier’s Apparatus

Heat of Hydration Test
The reaction of cement with water is exothermic. The reaction liberates a considerable quantity of heat. It is estimated that about 120 calories of heat is generated in the hydration of 1 gm of cement. The apparatus used to determine the heat of hydration of cement is known as calorimeter.60 gm of cement and 24 ml of distilled water are mixed for 4 minutes at a temperature between 15C. Three specimen glass vials 100mm are filled with this mixture, corked and sealed with wax. The vials are then stored with mixture in a vertical position at . The heat of hydration is obtained by subtracting the respective heat of solution of hydrated cement from the heat of solution of unhydrated cement calculated nearest 0.1 calorie.

Heat of Hydration Apparatus
Fig 5: Heat of Hydration Apparatus

Chemical Composition Test
Here, ratio of different composition of cement is calculated. It should be present within the limit. Ratio of percentage of lime to percentage of silica, alumina and iron oxide is known as Lima Saturation Factor (LSF) shall not be greater than 1.02 and not less than 0.66.

The weight of insoluble residue residue shall not be more than 4%.

Weight of magnesia shall not be more than 6%.

Total loss on ignition shall not be more than 5%.

Total sulphur content calculated as sulphuric anhydride shall not be more than 2.5%

Carbon Eating Bricks

Introduction
We often overlook the perspective of carbon emissions by cement materials in the construction industry. Several types of bricks have been invented by researchers for the betterment of the environment. Among such, one stands out as the Carbon-Negative Brick that cuts carbon emissions as well as construction cost by 50%. It is also known as Carbon Busters or Carbon Eating Bricks or Carbon Negative Bricks, and many more.

In the UK, this block was launched to collect more carbon dioxide than is produced (14 kg per tonne). This brick has high-performance properties and was developed by British business Lignacite, Ltd. in collaboration with Carbon8 Aggregates. It is made up of more than 50% recycled material, including Carbon8 pellets (produced from waste to energy plant thermal leftovers), water, and carbon dioxide. In order to create the carbon negative building block, the resulting unit has been included in the products of the company.
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STAAD Pro vs ETABS – Which is Better?

Introduction
This debate is common nowadays because of civil engineer’s shifted nature towards AI-based calculations and techniques. These software are used for designing 3D structures, analyzing them, and calculating reinforcements requirements in the building. These are very effective in saving time by engineers, avoiding long calculations that took days, and experimenting with various designs just by clicking on the moderations in seconds. These softwares are allrounder and are compatible with other BIM softwares too. Like for instance, the AUTOCAD drawing file can be imported to STAAD and nodes, and beams can be generated for analysis, and so on.

There are endless possibilities with these softwares, and it varies from person to person, company to companies whether they use these softwares for one motive or the other.
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TYPES OF FLOOR FINISHES

INTRODUCTION
While building houses it is important to take care of the exterior as well as interior of the building as occupants encourage having beautiful surroundings to enlighten their home. Along with wall finishes many occupants also refer various floor finishes to increase the aestheticy of their home. Floor finishes are upper part of the concrete slabs mainly covering the floors. There are various types of floor finishes which will be discussed here. Choosing the right kind of flooring is essential as to know which floor is preferable in what type of weather conditions. Like for instance, concrete or marble flooring can’t be used in cold weather conditions as it will make lower the temperature of the house more. So, in this case wood flooring is preferred as it helps to maintain a warmer temperature inside the house compared to outdoor temperature. All these will be discussed in details.
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