Engineering Laboratories Subjects

Explore Laboratories’ Subjects like building material's building constructions & maintenance Engineering, Civil engineering building drawing, building steel drawing/structures Public health engineering/Enviromental Engineering, Soil mechanics & foundation engineering, concrete technology, reinforced cement concrete drawings & reinforced brick structures, Transportation engineering, estimating costing & Valuation, R.C.C & transportation laboratories’,

Building Construction

&

BUILDING MATERIALS

THESE SUBJECTS ARE CO-RELATED TO EACH OTHER The construction of a building requires careful consideration of the materials and methods used to ensure its performance and security. The necessity of using the right building materials to keep the structure moisture-free is essential for its longevity. There are various types of construction structures, each with their own ways of performance and design. The proper use of materials is crucial in creating a secure and stable building. By understanding the necessity of building materials and the ways in which they contribute to the performance and security of a structure, construction can be carried out effectively and efficiently.

Acoustics of building followed by

BUILDING CONSTRUCTION PPT Link---------

https://engineersindiasolutions.blogspot.com/2024/07/building-construction.html

•Building acoustics are the method by which noise is controlled within a building. This includes measures in which to reduce noise when necessary (i.e. noise pollution) and how to ensure effective transmission of other sounds throughout a particular space.

•Acoustics looks first at the pressure levels and frequencies in the sound wave and how the wave interacts with the environment. This interaction can be described as either a diffraction, interference or a reflection or a mix of the three. If several media are present, a refraction can also occur •noise produced inside the hall like crying kids, the sound generated by type writers, fan, A/C, Refrigerators, etc.,

•equipment's must be serviced properly.

•equipment should be placed on sound absorbing mount.

•Floor, wall and ceiling must be covered with suitable sound absorbing materials.

•Building acoustics can help to mitigate the effects of noise disturbance which can have negative effects on health, wellbeing and general quality of life. The Noise Policy Statement for England (NPSE) defines noise pollution as: Environmental noise – which includes noise from

•transportation sources.•When it comes to materials, softer materials such as carpet, fiberglass insulation, and foam padding tend to absorb sound well, while harder materials such as concrete and brick tend to reflect it. Wood can reflect sound well, but if holes are drilled in it, it can also absorb it.

•Ernst Chladni (1756-1827), the 'father of acoustics'. Image from Wikimedia Commons. Ernst Chladni (1756-1827) is regarded by many historians as the 'father of acoustics' for his seminal experimental work on vibrations. He was also a well respected musician and inventor of musical instruments.

•the science that deals with the production, control, transmission, reception, and effects of sound is known Acoustics of Buildings

•In physics is foundational to the application in fields as varied as underwater sonar, ultrasound technology, architecture, music production, geology, communication, and atmospheric science

•While it may not be possible to avoid unwanted sounds completely, architectural acoustics allows interior designers to minimize unwanted distractions. While designing commercial spaces where music plays an integral part, architectural acoustics is used to ensure better reception of sound.

•Acoustical properties are those that govern how materials respond to sound waves, which are what we perceive as sound. We are all familiar with how a disturbance in a body of water will cause waves to develop and travel along the surface of the water in all directions away from the disturbance.

• Three factors affecting the acoustics of building

•i) Low ceilings help to reflect the sound towards the audience. ii) Sound absorbing materials are used in those parts of the hall where sound intensity is large. iii)Echo: The reflection of sound from a distant reflecting surface is known as echo

•Acoustic treatments are solutions that help to absorb or diffuse sound to improve the acoustic quality of a space. These treatments come in various forms, and some facilities may need multiple types of treatments to achieve the ideal acoustics for the space

•Different types of acoustic sensors:- such as microphones, hydrophones (underwater microphones), and accelerometers (which can indirectly detect acoustic vibrations). Each type of sensor is designed for specific applications, depending on factors like frequency range, sensitivity, and environmental conditions

•Four properties of sound: pitch, dynamics (loudness or softness), timbre (tone color), and duration.

Acoustics of Buildings IN Architecture

•Architectural Acoustics: The Art of Sound Design

•********************CONTINUED....................

Architectural Acoustics: The Art of Sound Design

As we’ve already suggested, good acoustic design can serve multiple purposes, including the following:

Decreasing stress and anxiety levels
Preserving hearing
Aiding in concentration
Reducing or minimizing hypertension
Improving speech communication
Maximizing the enjoyment of musical performances

Communication, in particular, is helped by good acoustics through the interplay of several factors. Properly designed acoustics aid in the clear transmission of verbal communication while at the same time reducing unwanted noise, thereby reducing distraction and aiding in concentration.

The elimination of loud noises, moreover, can contribute to the preservation of hearing over time.

Architectural Acoustic Techniques

Whether you’re designing an auditorium, library, or music hall, it’s important to understand the qualities of sound, how it’s transmitted, and techniques that can be used to control that transmission

Reverberation

{prolongation of a sound; resonance/ a continuing effect- a repercussion}

Reverberation is to sound what reflection is to light. Also known as resonance, reverberation refers to the amount of time it takes a sound to dissipate.

As sound waves bounce off surfaces in interior spaces, such as ceiling tiles and wall panels, noise builds up and reflects back on itself, reducing its clarity and making it harder to understand. It’s different types of ECHO'S, in which there’s a delay between the original sound and its fainter answer.

An echo off a distant canyon wall may take a few tenths of a second to return to you. But since the original sound only persists in your memory for 0.1 of a second, there’s no confusion. With reverberation, the reflecting surface (such as an interior wall) is much closer to you, and the time between when the original sound is made and reflected is less than 0.1 of a second.

The combination of the two can create the perception of a single, prolonged sound wave, which bounces back on itself, creating distortion.

Reverberation time is the amount of time needed for a sound to decay by 60 db (decibels) after being abruptly terminated. The higher the reverberation time, the noisier and more muffled a room can sound.

Buildings With Reverberation

Sometimes, you want to design a space with a higher reverberation time. Doing so can add to warmth and texture of music, so concert venues and symphony halls are likely to be constructed with higher reverberation times.

When high reverberation times are included in the design of a music venue, it can create a richer and more majestic experience. When they’re not, the music is likely to sound and feel smaller and more hollow

Buildings Without Reverberation

By contrast, if your venue is used primarily for speaking, such as a lecture hall, you’ll want to create acoustics with a lower reverberation time to preserve clarity. Failure to do so can result in miscommunication and frustration among attendees trying to make out what’s being said.

When low reverberation is included in a venue such as a conference room, listeners will remain engaged longer because it will take them less effort to hear and understand the message. When it’s not, they may “tune out” from frustration or leave feeling exhausted from having to focus, not just on the message, but on making sure they’re hearing it.

Sound Absorption

Sound absorption is the quality found in different materials that reduce reverberation times by absorbing sound energy and reducing sound levels. By eliminating unwanted sound, these materials can improve sound quality in a room.

Buildings With Sound Absorption

It can be helpful to use sound-absorbing material in rooms designed for speaking, such as lecture halls and conference rooms.

As mentioned above, different types of materials either reflect or absorb sound to different degrees. For Example, smooth concrete may absorb just 2% of sound, while reflecting the remaining 98%. In contrast, an acoustic panel — a glass fiber wrapped in fabric and mounted to furring (wooden strips) — with airspace behind it might absorb 75% of the sound that hits it.

Including sound absorption in a building’s design can help create a clearer, less cluttered sound quality by reducing reverberation: absorbing sound before it has the chance to bounce back. It can create a quieter, more peaceful environment.

Buildings Without Sound Absorption

Buildings without sound absorption are vulnerable to excessive reverberation because there’s nothing to remove the sound from the room before it can bounce back — thereby creating a noisier, busier environment. This can make it more difficult to hear spoken communication, make it harder to focus, and add to stress levels as a result.

Sound Insulation

Sound insulation is the property in a wall that allows it to keep noise from passing from one side to the other by absorbing sound waves of different frequencies. It can impact acoustic design by blocking air paths between rooms or between a room and the building’s exterior.

The effectiveness of sound insulation is measured in terms of dB Dw, with dB referring to decibels and Dw signifying the difference between the noise level in the room where sound is being produced and the level in a second, adjacent room, where it’s being heard or received.

The term sound insulation refers to how much sound is lost when it travels between the source room and adjacent room. If the dB Dw between two rooms is 45, that might mean the sound level is 65 dB in the source room and 20 in the adjacent room during a typical speech.

But if the speaker were to raise his voice, or even start yelling — at, say, 85 db — that would double the sound level in the other room to 40 db. In other words, the number of decibels (sound level) would increase by the same number in both rooms, rather than according to a ratio.

Sound waves need a medium through which to travel, most typically air. As a result, sound can travel through vents and electrical outlets or under doors — anywhere air can go. Sealing such spaces and adding insulation to venting systems are therefore effective ways of reducing unwanted sound.

Buildings With Sound Insulation

When a building includes sound insulation, it can minimize distractions from sound that emanates from adjacent rooms, whether it’s music, speech, or mechanical noise.

Acoustic insulation boards consisting of fiberglass panels and wrapped in cloth, as mentioned above, can absorb sound and effectively insulate adjacent rooms from the sound created in each of them, reducing background noise and improving focus.

Acoustic boards (also known as acoustic panels) are specifically designed with materials that absorb sound. They can be used in a number of spaces, including on walls or ceilings — especially at points where sound is known to reverberate — to reduce unwanted noise and create added clarity.

Buildings Without Sound Insulation

Buildings without sound insulation, on the other hand, can create problems for those occupying rooms that are side-by-side.

This is the kind of situation that leads people to complain about “thin” walls in motels and apartment buildings. But those aren’t the only places this problem can occur.

For instance, consider a school classroom with classrooms on both sides, and all are in session at the same time. Sound from both adjacent classrooms is likely to make it through the walls on both sides; if one class is a drama course in which students are reading from a script, loud voices could be particularly disruptive.

Or imagine if a classroom were adjacent to a basketball court during a physical education class. Without sound insulation, the bouncing of basketballs and squeaking of shoes on the hardwood floor could be extremely distracting in the classroom next door.

Acoustical Board

Acoustical design that utilizes acoustical boards not only minimizes human noise from adjacent rooms but also reduces noise created by HVAC units, whether they’re against exterior walls or on the roof.

Using acoustical panels can be highly effective. Fiberglass black acoustical ceiling and wall liners are inexpensive and effective ways to reduce noise while being integrated seamlessly into a structure.

Panels may be situated in a variety of ways. They may be freestanding, mounted on walls, or suspected from ceilings. They may also be inserted between two walls. Vertical panels prevent sound from moving across a room from one end to the other, while horizontal panels absorb sound directly.

Wall-mounted acoustic panels can be especially helpful in small rooms, where sound tends to reverberate off walls because they’re close to the source of the sound. By contrast, ceiling panels can be more useful in larger venues where the sound source is farther from any surface and may reverberate off ceilings.

Acoustic boards can also be made using other inexpensive materials such as packaging foam, but these may be less effective at reducing sound.

Buildings With Acoustical Boards

Buildings with acoustical boards will be able to minimize artificial noise created by HVAC and other mechanical units. These mechanical systems can prove distracting when they switch on and off; thoughtful acoustic design using acoustical boards can help prevent or mitigate this annoying background noise.

Buildings Without Acoustical Boards

Buildings without acoustical boards are vulnerable to disruptions caused by HVAC units — especially during seasons that experience temperature extremes — when air conditioning units, in particular, can labor for long hours or repeatedly activate and shut off as temperature targets are met or exceeded.

Challenges of Architectural Acoustics

Architectural acoustics creates a number of challenges during construction, both as it relates to building acoustics — insulation from unwanted sound — and room acoustics, or maximizing sound quality.

The challenges take place both in the process itself and in reaching the intended goal. They include controlling noise pollution, dealing with environmental noise, and predicting sound distribution.

Controlling Noise Pollution

Controlling noise pollution can involve dealing with noise from HVAC Systems once they’re installed to minimize noise pollution from the construction process itself noise pollution

The Environmental Protection Agency defines

as “unwanted or disturbing sound,” adding that “sound becomes unwanted when it either interferes with normal activities such as sleeping, conversation, or disrupts or diminishes one’s quality of life.”

OSHA considers anything causing or exceeding 85 dB over an eight-hour period to be noise pollution. Excessive noise over prolonged periods, as mentioned earlier, can cause stress, anxiety, sleep disturbances, hearing loss, and high blood pressure, among other negative effects.

Choosing low-noise machinery can help minimize noise pollution. So can creating noise barriers and scheduling high-volume work for times when fewer people are nearby.

Environmental Noise

Sound passing between walls of adjacent rooms isn’t the only challenge you’ll face in designing and constructing a building. Location matters, too: a lot. If your project is on a long driveway off a rural road, you’ll have a lot less environmental noise to deal with than if you’re building a convention center at the heart of downtown.

You’ll need to choose building materials and insulation to account for external noises such as heavy vehicle traffic, construction (if you’re in the middle of a developing area), pedestrian conversations, mobile food vendors, and ambulance or police sirens, depending on the location and its environment.

The challenges are different in DIFFERENT AREAS AS ER THE TOPOGRAPHICAL CONTIONS

Sound Distribution

The larger a room is, the bigger the challenge of measuring sound distribution. Doing so requires more than measuring reverberation because the sound quality is likely to be different at various points around the room.

Sound distribution refers to where sound travels in a room. This is particularly important in large venues such as theaters, where audience members are distributed at different angles and distances from the sound source. n a concert hall, for instance, the acoustics are likely to be different in front of the stage than in the wings or in the balcony. To measure sound distribution, you can place a sound source in position (for example, where the stage will be) and measure sound pressure levels at different locations around the room.

Open Concept Spaces

Open concept spaces in office buildings are designed to foster collaboration and remove barriers between employees, such as office walls and cubicle barriers. Counterintuitively, however, Harvard University’s Business Reviews that face-to-face interactions actually fell by 70% when companies made the switch to open offices.

Sound can travel across entire open spaces in such offices, creating distractions that can be avoided if insulated walls are in place. Ringing phones, employee conferences, and noise from office machinery such as photocopiers can make employees want to hunker down rather than open up and interact more.

Removing sound isolation, ironically, can create a desire for more actual isolation in such offices.

Conclusion

Accounting for potential sound variations and acoustical challenges during the design phase of any construction project will make your job easier and maximize your chances of success in the long run.

It will allow you to design rooms in the proper shape to create the best possible architectural acoustics, as well as to select the best building materials to serve as sound absorbers and diffusers where necessary. You’ll also be able to select the proper equipment for the construction job you’re planning.

Whether you’re soundproofing walls for a recording studio, creating greater resonance in a concert hall, or improving the functionality of walls separating conference rooms or classrooms, you can be sure you’re on your way to a successful construction project if you consider the elements of good architectural acoustics.

PPT Link https://engineersindiasolutions.blogspot.com/2024/07/acoustics-of-buildings-architectural.html