Materials for Aesthetic, Energy-Efficient, and Self-Diagnostic Buildings

Main Paper Used: Materials for Aesthetic, Energy-Efficient, and Self-Diagnostic Buildings John E. Fernández Science , New Series, Vol. 315, No. 5820 (Mar. 30, 2007), pp. 1807-1810 Published by: American Association for the Advancement of Science Article Stable URL: http://www.jstor.org/stable/20035896

More sources listed in REFERENCES slides 39-40

Overview

Materials for Building Structures

PurposeThe most basic purpose of materials science when building structures is to make sure the structures remain structures. As construction companies look to test the limits of science and engineering buildings, it is important to have a thorough understanding of all materials used to make sure the buildings are safe and standing for as long as they are in use.

Citations:http://www.thepetronastowers.com/wp-content/uploads/2010/02/petronas-towers1.jpghttp://www.blottr.com/sites/default/files/imagefield/collapsed-building483_001-6398.jpg

Basics of Structure Design Superstructure (above ground)

Collects and distributes all elements of the building weight and imposed loads from environment.

Diverts forces from all directions down towards the substructure.

Substructure (below ground). Supports mass of entire

structure. Distributes all forces into the

ground without damaging underground formation stability.

Materials Question:How to collect and distribute load using the most efficient and effective material properties?Citations:

http://eu.lib.kmutt.ac.th/elearning/Courseware/ARC261/images/chapterPics/chp1pic6.jpg

Challenges Lifetime Service Reliability

Use technology to make sensors and materials that administer a useful level of repair and self-healing.

Use materials to increase lifetime of buildings (currently ~ 100 years).

Use new materials to withstand catastrophic conditions.

Material Efficiency Reduce cost per unit weight of materials as well as

overall environmental and resource waste during construction. 60% of non-industrial waste comes construction and demolition of buildings.

Reduce resource demands for building structures.

Energy Efficiency How to reduce energy consumption of building and

running modern buildings. 40% of total energy and 60% of electricity in developed countries consumed by buildings.

Citations:http://oregoncub.org/uploads/Customersl-Energy-Efficiency.jpg

Solution Examples: Engineered Woods

Material Efficiency Made from a variety of wood waste

products.Customizable properties

Can be engineered for specific purpose and properties, rather than relying importing specific types of timber.

Increased dimensional Stability Current research includes textile and

fiber reinforcement for higher strength and stiffness than that offered by natural woods.

By combining wood scraps and particles with adhesives and polymer materials, new wood products can be designed with optimized properties. Engineered woods are often stronger and lack many mechanical weaknesses of natural wood.

Citations:http://www.nachi.org/images10/engineeredwood.jpg

Layers of engineered woods can be used to optimize properties for each application.

Solution Examples: Advanced Steel AlloysThermal Stability

A common hazard in building structures from steel is the potential for melting in case of fire. Using alloying methods, the thermal stability of steel can be raised above fire temperatures.

Earthquake Stability Use steel-polymer-steel sandwich in substructure for earthquake resistance. By combining the

strength of steel with nonlinear viscoelastic behavior of rubber materials, isolation bearings for buildings in seismic zones can withstand catastrophic conditions.

Citations:http://onlinelibrary.wiley.com/store/10.1002/mame.201200058/asset/image_m/mgra001.jpg?v=1&s=ae214cb60debee5e10edddcb5a75738a1c3ca543

Solution Examples: Concrete Additives

Ultahigh-performance fiber-reinforced concretes (UHPFRC)

• Steel whiskers distributed in highly engineered an compacted concrete.

• Recent work has produced nano-enabled flexible concrete.

Relative to conventional concrete:•500x as resistant to cracking•40% lighter per unit weight

Aerated Autoclaved Concrete

• Foamed concrete material.

• Light and soft enough to be cut with a saw and stacked like masonry

Citations:http://www.understanding-cement.com/images/aircreteblock.jpghttp://1.bp.blogspot.com/_6S-Xn-eMfg4/S8dfRvkdJEI/AAAAAAAAADw/RJjTuqD_9I8/s320/UHPFRC.pnghttp://ars.els-cdn.com/content/image/1-s2.0-S0734743X09001663-gr1.jpg

Materials for Exterior Enclosures

Materials for Exterior Enclosures

The exterior enclosure plays a very crucial role in making the inside of a building reliable and habitable no matter the conditions outside the building. A list of the main conditions that are maintained are seen below.

• Air

• Water

• Acoustic pressure

• Pollutants

• Radiant heat

• Visible

Without advances in the materials used to safeguard the building from these conditions, the building would become obsolete or need expensive and constant upkeep. However, advances in these materials reduce the need for further maintenance while reducing cost.

*Fernandez, J. E.. Science 315.5820 (2007): 1807-1810. Print.

*Wroblaski, Kylie. “Self-Cleaning Glass Saves Time, Money, and Water.” Building.com Chris Olson, 01,Mar. 2010. Web. 13 Apr. 2013

Modern Insulation Materials

Compared to mineral wood and natural fibers that were once used for insulation, modern day materials are 1.5 to 3 times as resistant to the flow of heat.

There are many different types of materials that can be used, which can be arranged in many different manners depending on the consumer. Typical materials include:•Blankets of loose nonwoven glass fibers•Treated cellulose•A variety of different polymer foams

“There is also an option for high-performance systems which have vacuum and gas filled panels encased in aluminized Mylar pillows as well as aerogel materials of foamed silica capable of thermal resistance as low as .008 W m^-1 K^-1

The figure above depicts a worker filling a cavity wall with Polyurethane foam.

Citation:http://www.which.co.uk/energy/creating-an-energy-saving-home/guides/cavity-wall-insulation/cavity-wall-insulation-installation/

Material Advances in Windows

One of the products that could help in the fight against outside conditions are windows. In today’s world it seems as though everyone wants more windows. However, with more windows comes higher operation costs due to heat, glare and cleaning.

There have been advances in window technology that can decrease thermal conductance by as high as 17.5 times. However, at this time the materials that exist are relatively expensive and have to be installed carefully.

Another promising advance deals with an active glaze that is placed on the outside of the window. These materials could potentially reject unwanted solar heat while maximizing sunlight.

Finally, there have been self-cleaning materials developed . These materials are in one of two categories: hydrophobic and hydrophilic.

This Figure above shows the thermal conductivity of different window technology that is known today.

Citation:http://gfp.lbl.gov/performance/default.htm

Self-cleaning GlassBreakthroughs in self-cleaning window technology will eventually allow windows to stay clean without any human help. The process uses a coating on the window that contains TiO2. This coating helps the windows clean themselves in two ways. (4)

1.The breakdown of organic materials deposited on the glass2.The sheeting of rainwater, which washes the glass

The TiO2 takes around 5 days to become activated from UV light. This UV light also helps break down the organic dirt and other materials on the window through hydrolysis.

The surface of the glass is also hydrophilic and tends to dry quicker than other windows because of the coating. The windows also show reduced amounts of streaks and bubbles.

The dome of the newly renovated Robson Square ice rink in Vancouver, BC, is covered with nearly 9,000 square feet of self-cleaning glass, combined with low-E glass. PHOTO COURTESY OF PILKINGTON NORTH AMERICA INC.*Wroblaski, Kylie. “Self-Cleaning Glass Saves Time, Money, and Water.” Building.com Chris Olson, 01,Mar. 2010. Web. 13 Apr. 2013

If the glass is used in a region where large deposits of inorganic materials are present, the glass will lose some of its effects. For example, if the window has inorganic materials on it the photo catalytic process will not work. This is because the inorganic material will be in contact or connected to the organic materials. This means the window would act as if no coating had ever been applied.

However, another upside to this coating is that it is said that the photo catalytic performance of the coating will remain the same as long as the window stays the same. Russell Davies explained this by saying, “It’s a catalyst, so it’s not sacrificial; it maintains itself. It’s integral with the glass and shouldn’t degrade over time.

Citation:http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookplanthorm.html

Self-cleaning Glass

Materials for Building Services

Purpose of Building Services Engineering

•Optimization of Interior Environment of Buildings•Create an interior work environment tailored to the needs of employees•Careful regulation of heating, cooling, lighting, and other systems in modern buildings

•Minimization of Building Wastes and Overall Environmental Burden of Buildings•Research of new materials to decrease electricity consumption and waste production

Citations:Science. 315, 1807-1810, 2007.Image:http://www.topboxdesign.com/wp-content/uploads/2011/10/interior-office-building-of-Almac-Group-Headquarters.jpg

Interior office space at Almac Group Headquarters

Cooling Solutions: PECW Passive Evaporative Cooling Walls (PECW)

Control increased surface temperatures of walls during warm summer months

Use pipe-shaped porous ceramics to soak up water using capillary force

Allow wind to penetrate the wall and reduce surface temperature using evaporation

Decrease air temperature between 3-8 oC during summer months

Capillary Action: a phenomenon associated with surface tension and resulting in the elevation or depression of liquids in capillaries

Cooling effectiveness and directionality is dependent on the direction and velocity of incoming air, as well as shade

Citations:Building and Environment. 45, 461-472, 2010.Definition of Capillary Action: http://wordnetweb.princeton.edu/perl/webwn?s=capillary%20actionImages:

Schematic showing how PECW walls work

Phase Change Wallboards (PCMs) are traditional gypsum wallboards embedded with phase-change microcapsules

Reduce heating and cooling costs during warm summer months and cold winter months

In high temperatures, phase change materials (PCMs) thaw in high temperature and absorb heat from rooms

In cool temperatures, PCMs absorb overhead heat at night and release heat during the day

Can potentially reduce need and usage for extensive commercial air conditioning systems

Citation:Envelope Technologies for Building Energy Efficiency. 2, 1-5, 2006.Images: http://www.treehugger.com/green-architecture/why-is-phase-changing-drywall-in-the-news-instead-of-in-the-home-depot.html

Heating Solutions: Phase Change Wallboards

How PCMs Work

Effect of PCM on Room Temp. over Several Days

Solar Panel Technology Silicon-based photovoltaic (PV) cells

Absorb and convert sunlight directly into energy

Account for 99% of all solar panel production

Single-crystal and amorphous currently in use have an average efficiency of 12.5%

Environmentally-friendly Challenges:

Increasing efficiency of cells to compete will other energy sources such as coal, oil, and natural gas

Creating new photovoltaic devices that are more economically feasible

Citations:Science. 315, 1807-1810, 2007.: Image: http://www.ce.gatech.edu/node/5701

Silicon-based PV cells atop G. Wayne Clough Undergraduate Learning Commons at Georgia Tech University

Advancements in PV Cells Research into PV Cells using New Materials:

CuInSe2 and CdTe cells have been produced in laboratories have shown efficiencies near 20%

TiO2 nanorod cells have been developed that can absorb light over a wide range of wavelengths using quantum dots

Recently developed Cu(In,Ga)Se2 thin-film cells have claimed the world record for PV cell efficiency - beyond 20% efficiency!

Citations:Science. 315, 1807-1810, 2007.Photovolt: Res. Appl., 19: 894–897. doi: 10.1002/pip.1078

Artificial Lighting in Buildings Energy Consumption in the U.S.

Artificial lighting accounts for 8% of total energy consumption

Accounts for 20% of nationwide electrical energy consumption

Current Technology used for Artificial Lighting Incandescent Bulbs

Electric currents produce light using a heated filament

Consume 42% of electrical energy lighting Highly inefficient power consumption

Short lifetimes 90% of power consumed by these lights

is lost as heat Leads to increased cooling costs

Citations: Science. 315, 1807-1810, 2007.Image: http://www.allenergies.net/images/LED/incandescent_bulb.jpg

Incandescent Light Bulb

A New Era of Material Innovations

for BuildingsCitation Box

http://www.treehugger.com/green-architecture/nox-sucking-sidewalks-could-save-lives-or-at-least-lungs.htmlhttp://www.certainteed.com/products/insulation/mold-prevention/317391

Titanium Dioxide Coating Polyamide

Citation Box

http://www.envirocitizen.org/article/how-does-green-building-improve-the-environment/6126.htmlhttp://goleyinc.com/sites/default/files/thumbs_480/amembrainwallmdsmall%5B1%5D-1.jpg

PolyamideTitanium Dioxide Coating

• Originally used for its self-cleaning and aesthetic properties

• Due to unintended consequences, its pollutant removing properties were discovered

• Because of its discovery as a “green” building material, lots of research is being done to optimize its manufacturing and ensure its safety

• Has been a popular material for many non-building uses for decades

• Due to additional research, its previously overlooked vapor barrier properties are now utilized as sheeting inside building walls to prevent moisture build-up

• As a result, polyamide has greatly reduced rot, mold, corrosion, and mildew

Abstract

Citation Box

http://www.boralna.com/brochures/ordering/PDF/boralpure-color-

collection.pdf?site=boral_na&company=Roof Tiles

1 The Titanium Dioxide coating on the tile oxidizes harmful Nitrogen Oxides released from vehicles. This results in cleaner air that is safer to breathe.

2 The coating is a photo-catalyst, activated by the UV rays of the sun. The nitrogen oxides are converted into calcium nitrates.

3 As it rains, calcium nitrates are washed off the roof.

How it Works

Titanium Dioxide

Challenges for the Future

Manufacturing Sustainability

Testing and studies are currently ongoing to find a way to lower the negative environmental impact in manufacturing Titanium Dioxide.

Due to many concerns that were posed in the previous slide, many environmentalists are worried about shifting the smog problem from skyscrapers to factories.

Companies developing this technology are required to gradually improve their process to not exceed pollution limits set by the EPA.

Citation Boxhttp://news.thomasnet.com/green_clean/2012/05/22/titanium-dioxide-coats-buildings-structures-to-help-them-stand-up-to-smog-monster/http://thumbs.dreamstime.com/x/green-factory-9877423.jpghttp://chicagoagentmagazine.com/wp-content/uploads/2012/11/green-building-market-2013-dodge-report-green-building-outlook-mcgraw-hill-construction.jpg

Environmentally friendly buildings and factories

Titanium Dioxide

Citation Boxhttps://upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Rutile-unit-cell-3D-balls.png/200px-Rutile-unit-cell-3D-balls.pnghttp://news.thomasnet.com/green_clean/2012/05/22/titanium-dioxide-coats-buildings-structures-to-help-them-stand-up-to-smog-monster/http://www.observatorynano.eu/project/filesystem/images/2ch.ve.1.p11.jpg

Many studies have shown that titanium dioxide nanoparticles are both cytotoxic [leads to cell death] and carcinogenic.

As a result, it is crucial to figure out how these titanium dioxide nanoparticles might degrade, and where they will be when they do degrade

Challenges for the Future

Potential Health Hazard

60000x magnification of TiO2

TiO2 Nanoparticles

Titanium Dioxide

Used as a “smart” vapor barrier in exterior envelopes

Use #1: Increases water vapor Permeability in high humidity

Use #2: Reduces risk of rot, corrosion, and growth of mold and mildew

Citation Boxhttp://danshamptons.com/wp-content/uploads/2012/01/no-mold-434x435.jpghttp://www.menards.com/main/store/

20090519001/items/media/Wallcoverings/certainteed_wall/

ProductLarge/MEMBRAIN_VAPOR_BARRIER_Imag

e_Alternate.jpg

Polyamide / Nylon

How it Works

When there is very little moisture inside the walls, the vapor molecules inside the buildings are repelled by the Polyamide vapor barrier. (Pores are closed)

But, when moisture collects inside the wall, the polyamide vapor barrier becomes highly permeable, allowing the water vapor to escape from inside the wall. (Pores are open)

Citation Boxhttp://www.certainteed.com/products/insulation/mold-prevention/317391#

Polyamide / Nylon

Conclusions• The advances in insulation materials is very

promising and has a bright future. I believe that if cellulose insulation becomes the industry standard for both residential and industrial buildings, the benefits will not only affect those today, but also future generations.

• The production of cheaper and more effective windows has huge potential

• Polyamide as a vapor barrier is a more developed and less risky material to use, compared to titanium dioxide coating. However, they have different benefits for this society, and improving both will definitely help us in the future!

As efficiency becomes more important, the potential for improvement in performance from new materials, together with partnerships between material science and engineering, may offer real breakthroughs for the future.

Citation:http://mw2.google.com/mw-panoramio/photos/medium/12969984.jpg

Greatest building ever.

• Materials for Aesthetic, Energy-Efficient, and Self-Diagnostic Buildings John E. Fernández Science , New Series, Vol. 315, No. 5820 (Mar. 30, 2007), pp. 1807-1810 Published by: American Association for the Advancement of Science Article Stable URL: http://www.jstor.org/stable/20035896

• http://news.thomasnet.com/green_clean/2012/05/22/titanium- dioxide-coats-buildings-structures-to-help-them-stand-up-to-smog-monster/

•http://www.certainteed.com/products/insulation/mold-prevention/317391

•Hamed Babaizadeh, Marwa Hassan, Life cycle assessment of nano-sized titanium dioxide coating on residential windows, Construction and Building Materials, Volume 40, March 2013, Pages 314-321, ISSN 0950-0618, 10.1016/j.conbuildmat.2012.09.083. (http://www.sciencedirect.com/science/article/pii/S0950061812007611)

•"Insulation and the Environment." CIMA –. N.p., n.d. Web. 23 Apr. 2013.

•Fernandez, J. E.. Science 315.5820 (2007): 1807-1810. Print.

References

References

• Wroblaski, Kylie. “Self-Cleaning Glass Saves Time, Money, and Water.” Building.com Chris Olson, 01,Mar. 2010. Web. 13 Apr. 2013

• Avril, F., Rahmé, R., Doux, M., Verchere, D., Sage, D. and Cassagnau, P. (2012), New Polymer Materials for Steel/Polymer/Steel Laminates in Automotive Applications. Macromol. Mater. Eng.. doi: 10.1002/mame.201200058

• S.G. Millard, T.C.K. Molyneaux, S.J. Barnett, X. Gao, Dynamic enhancement of blast-resistant ultra high performance fibre-reinforced concrete under flexural and shear loading, International Journal of Impact Engineering, Volume 37, Issue 4, April 2010, Pages 405-413, ISSN 0734-743X, 10.1016/j.ijimpeng.2009.09.004. (http://www.sciencedirect.com/science/article/pii/S0734743X09001663) Keywords: UHPFRC; Dynamic increase; Fibre reinforcement; Blast

• Building and Environment.  45, 461-472, 2010.

• Envelope Technologies for Building Energy Efficiency.  2, 1-5, 2006.