‘GREEN’ BUILDINGS

‘GREEN’ BUILDINGS:..................................................................................................................

Are ‘green’ buildings working from the building users’ perspective? This paper presents initial findings from 45 Australian buildings  with a view to highlighting lessons towards developing successful green buildings. By ‘green’ we mean buildings that have been created with explicit intent to include environmentally sustainable design (ESD) features and principles. Although the objective may be to create buildings with less environmental impact, they may not necessarily achieve this in reality. While the relative performance of buildings can be measured in terms of aspects such as water and energy efficiency, it is vital to understand the experience of the buildings from the users’ point of view. Not only can a poorly performing building affect users’ well being and productivity, in addition, subsequent measures needed to alleviate users’ discomfort can result in great expense and in the building failing to achieve its efficiency targets. Our discussion here deals with end-user responses. A more complete picture would require study of both technical performance, including detailed energy assessment using measured data over a period of time, in conjunction with occupant surveys. This is not attempted within the present study, which is limited to building users’ experiences and feedback.

Why do occupants appear more tolerant
of green buildings?


Indoor environment research on thermal comfort  show that users are more often tolerant of conditions where they have more control, sometimes irrespective of whether conditions are actually physically better. Users appear to be happier if they understand how the building is supposed to work either because the design intent is made clear and/or because the controls are easy to understand and work well.

Homebuilders Go Green

 

• As green technology becomes more prominent, the construction industry may see a further shift in that direction to accommodate increasing demand. This isn't merely the case with private homes. Green technology is also being adopted in the commercial sector, and as we've seen recently, college campuses.

  The building was designed by 60 interdisciplinary students from Stevens for the U.S. Dept. of Energy’s 2013 Solar Decathlon Competition. The biannual competition features 20 university teams from around the world competing to design energy-efficient solar homes. It culminates Oct. 3-13, as the homes are displayed to the public. Once the competition is finished, the team from Stevens will donate its building, dubbed “Eco Habit,” to CSUSM. 

  The technologies incorporated into the new veteran’s center will include solar shingles, a rainwater harvesting system, as well as an energy-and-water-saving system for heating, cooling, and plumbing. The building will also have a central control program which collects and analyzes sensor data from each system in order to maximize efficiency. 

Root Zone Treatment Technology for Sewage

root zone treatment Technology for sewage::


The process in a root zone system to treat the sewage is very simple to explain yet complex in nature. Raw effluent (after removing grit or floating material is passed horizontally or vertically through a bed of soil having impervious bottom. The effluent percolates through the bed that has all the roots of the wetland plants spread very thickly . nearly 2,500 types of bacteria and 10,000 types of Fungi, which harbor around roots get oxygen form the weak membranes of the roots and aerobically oxidize the organic matter of the effluent.

The characteristics of plants of absorbing oxygen through their leaves and passing it down to roots through their stems which are hollow, is utilized as a bio-pump. Away from the roots, anaerobic digestion also takes place. The filtering action of the soil bed, the action with fungi etc. and chemical action with certain existing or added inorganic chemicals help in finally obtaining a very clear and clean water.

The system of plants regenerates itself as the old plants die and form useful humus. Hence the system becomes maintenance free and can run upto 50 to 60 years without any loss of efficiency as has been described. 

It is advantageous to treat the sewage by root zone system. It achieves the standard for tertiary level treatment standard with no operating cost. There is no chemical used for pH adjustment or for flocculation. Low electricity is consumed for pumping treated water from the collection tank to the reed bed. From the reed bed the treated water is collected and used for irrigation by gradient flow. 

The root zone system has low maintenance cost since it involves no machinery and its associated maintenance. It requires negligible attendance for operation and monitoring. It has no sludge handling problem such as scraping of slurry from the sludge drying beds and its disposal twice in a week. 

• It enhances the landscape and gives the site a green appeal.
• It provides natural habitat for birds and after a few years gives an appearance of a Bird´s sanctuary.
• It is though an effluent treatment plant, it does not have odour problem and though
• It is a green zone, it does not have mosquitoes problem.
• The reeds are not grazed by ruminants.
• Salinity may not be a problem for a survival or operations of reed beds.
• It is recommended to combine vertical flow and then horizontal flow of sewage with a soil having impervious bottom.
• In the horizontal flow system, the sewage percolates through bed and that has all roots of the wetland plants spread very thickly nearly with 2500 types of bacteria and 10,000 types of fungi and aerobically oxidized organic matter of the effluent.
• Root zone system gives a very good performance of removing 90% BOD and 63% Nitrogen.
• Phragmites australis has been found more efficient in nitrogen removal compared to Typha latifolia.

kalpasar project

The Kalpasar Project envisages building a dam across the Gulf of Khambat for generating tidal power and for establishing a huge reservoir for fresh water for irrigation, drinking and industrial purposes. A 10 lane road link will also be set up over the dam, greatly reducing the distance between Saurashtra and South Gujarat.

Gujarat has been a water scarce State with 70% of the water resources available in 25% of the geographical area. Saurashtra in particular has been a region with water shortage for agricultural land. Additionally, the water storage capacity in Gujarat is quite lower that the rainwater availability. To meet these challenges, the idea of storing 10,000 MCM (million cubic metre) additional rainwater by developing a freshwater reservoir in the Gulf of Khambhat came up.

There are several benefits foreseen as an outcome of the Kalpasar Project. Some of them are as following:

• Nearly 10.54 ha. Land in 39 talukas of 6 districts of Saurashtra region will be provided with irrigation facilities.
• The increase in irrigation intensity will be upto 46% as compared to the current increase of 19%.
• The travel distance between Bhavnagar and Surat is expected to decrease leading to better connectivity to the faster growing city of Surat.
• The land which gets frequently submerged in the periphery of Gulf of Khambhat will be reclaimed.
• The development of land with Kalpasar Project will also enhance accessibility to other projects such as Dholera SIR and Delhi- Mumbai Industrial Corridor
• The saline ground water will be converted to sweet water leading in improved quality of water for drinking and agricultural purposes.
• The pumping of irrigation water will be done with the renewable resource of Wind Energy.

LIGHTWEIGHT CONCRETE (AAC BLOCKS)

ACC is a highly thermally insulating concrete-based material used for both internal and external construction. Besides AAC's insulating capability, one of its advantages in construction is its quick and easy installation, because the material can be routed, sanded, or cut to size on site using standard carbon steel power tools.

Even though regular cement mortar can be used, most of the buildings erected with AAC materials use thin bed mortar in thicknesses around ⅛ inch, depending on the national building codes. AAC materials can be coated with a stucco or plaster compound to guard against the elements, or covered with siding materials such as brick or vinyl.

Aerated Light Weight concrete is today recognized the world over as an environment friendly product due to its superior

insulating and energy saving properties. Increased use of Siporex helps to conserve and protect our planet's forest cover.

Unlike most other concrete applications, AAC is produced using no aggregate larger than sand. Quartz sand, calcined gypsum, lime (mineral) and/or cement and water are used as a binding agent. Aluminum powder is used at a rate of 0.05%–0.08% by volume (depending on the pre-specified density). In some countries, like India and China, fly ash generated  from thermal power plants and having 50-65% silica content is used as an aggregate.

When AAC is mixed and cast in forms, several chemical reactions take place that give AAC its light weight (20% of the weight of concrete) and thermal properties. Aluminum powder reacts with calcium hydroxide and water to form hydrogen. The hydrogen gas foams and doubles the volume of the raw mix creating gas bubbles up to 3mm (⅛ inch) in diameter. At the end of the foaming process, the hydrogen escapes into the atmosphere and is replaced by air.

When the forms are removed from the material, it is solid but still soft. It is then cut into either blocks or panels, and placed in an autoclave chamber for 12 hours. During this steam pressure hardening process, when the temperature reaches 190° Celsius (374° Fahrenheit) and the pressure reaches 8 to 12 bars, quartz sand reacts with calcium hydroxide to form calcium silica hydrate, which gives AAC its high strength and other unique properties. Because of the relatively low temperature used AAC blocks are not considered fired brick but a lightweight concrete masonry unit. After the autoclaving process, the material is ready for immediate use on the construction site. Depending on its density, up to 80% of the volume of an AAC block is air. AAC's low density also accounts for its low structural compression strength. It can carry loads of up to 8 MPa (1,160 PSI), approximately 50% of the compressive strength of regular concrete.

• Improved thermal efficiency reduces the heating and cooling load in buildings.
• Porous structure allows for superior fire resistance.
• Workability allows accurate cutting, which minimizes the generation of solid waste during use.
• Resource efficiency gives it lower environmental impact in all phases of its life cycle, from processing of raw materials to the disposal of waste.
• Light weight saves cost & energy in transportation, labor expenses, and increases chances of survival during seismic activity.

Slip form work::

Slip form is similar in nature and application to jump form, but the formwork is raised vertically in a continuous process. It is a method of vertically extruding a reinforced concrete section and is suitable for construction of core walls in high-rise structures – lift shafts, stair shafts, towers, etc. It is a self-contained formwork system and can require little crane time during construction.

This is a formwork system which can be used to form any regular shape or core. The formwork rises continuously, at a rate of about 300mm per hour, supporting itself on the core and not relying on support or access from other parts of the building or permanent works.

Commonly, the formwork has three platforms. The upper platform acts as a storage and distribution area while the middle platform, which is the main working platform, is at the top of the poured concrete level. The lower platform provides access for concrete finishing.Productivity models for the application of slip forms to the core of high-rise buildings and silos are designed using simulation.These models consider several factors that affect productivity,suchas stoppage times, jacking rates, silo diameter, placing method, cross section area, and concrete setting time. Several charts are developed to determine productivity of slip forms considering different stoppages, core cross section area, and concrete placing methods. The models are tested and show high accuracy in predicting slip-form productivity.

• Slip form does not require the crane to move upwards, minimising crane use.
• Since the formwork operates independently, formation of the core in advance of the rest of the structure takes it off the critical path – enhancing main structure stability.
• Availability of the different working platforms in the formwork system allows the exposed concrete at the bottom of the rising formwork to be finished, making it an integral part of the construction process.
• Certain formwork systems permit construction of tapered cores and towers.
• Slip form systems require a small but highly skilled workforce on site.
• Completed formwork assembly is robust.
• Strength of concrete in the wall below must be closely controlled to achieve stability during operation.
• Site operatives can quickly become familiar with health and safety aspects of their job
• High levels of planning and control mean that health and safety are normally addressed from the beginning of the work.
• This formwork is more economical for buildings more than seven storeys high.Little flexibility for change once continuous concreting has begun therefore extensive planning and special detailing are needed.
• Setting rate of the concrete had to be constantly monitored to ensure that it is matched with the speed at which the forms are raised.
• The structure being slipformed should have significant dimensions in both major axes to ensure stability of the system. 

Smarter Parking Technology

How Smarter Parking Technology Will Reduce Traffic Congestion::

Between 8% and 74% of traffic in congested downtown areas is caused by people cruising for parking, according to a report by UCLA professor Donald Shoup who synthesized studies from 70 years of research on the subject. The paper indicates that drivers in major cities — including San Francisco, Sydney, New York and London — spend between 3.5 and 14 minutes searching for a space each time they park.

The last study Shoup included in his report ended in 2001. Today, wasted cruising time is likely longer, and it's on track to get worse. During a recent Ted Talk in March, Ford Motor Company Executive Chairman Bill Ford Jr. estimated that the number of cars on the road could go from 800 million to nearly 3 billion by 2050.

While the sci-fi possibilities of Ford's full vision have yet to be realized, many companies and cities have started implementing smart solutions for parking and traffic problems. What they're learning in these first steps may help shape the future of smart driving.

The city of Los Angeles recently installed low-power sensors and smart meters to track the occupancy of parking spaces throughout the Hollywood district, one of its most congested areas. The sensors are about the size of a coffee cup lid and are embedded in the asphalt. The smart meters attach to regular meters and allow users to pay with their mobile phones in addition to communicating payment information to the city.

With the information from the sensors, the city is able to change pricing on its parking depending on demand — raising it for a special event or a particularly busy hour, for instance. The information also alerts enforcement officials about expired parking meters or other parking violations and reduces the time they spend driving in circles.

Drivers can also access information gathered by the sensors through a free app called Parker. The app alerts drivers where there they are or are not likely to find an available parking space so that they can save time cruising around.

"Once you have this infrastructure of sensors throughout a city, you can use these networks in a number of different ways," she says. "We’re starting in parking today, but eventually you can envision this being used for measurement of pollution or to detect if a water pressure system in a fire hydrant is operating at the right pressure or if a streetlight bulb needs to be replaced. ... there are lots of smart city applications that can be built on top of this."