Group10 - Long Life: Weathering Lucas Flaa & Sean Ryan & Patricia McKissack & Rene Gloria
What is Weathering? Weathering is the disintegration of rock and the physical and chemical breakdown of rock and minerals on the earths surface. Weathering leads to erosion witch removes soil and rock and moves it from location to location altering riverbeds, digging canyons, and dissolving limestone to form caves. Weathering can lead to various issues to a structure overtime but with proper designs weathering can be used to ones advantage.
Types of Weathering Freeze Thaw: Common in rocks, water seeps into the cracks of rocks and after the water freezes the cracks expand. Over time the freeze thaw will repeat and can eventually break the rock apart. Exfoliation: Common in warm areas. Sun shines on the rocks and expand during the day. At night they cool and contract, overtime flakes of rocks begin to fall off. Chemical: AN alteration to the chemical composition of a rock due to a reaction commonly due to acidic water dissolving the rock. Can be seen in limestone turning it into a limestone pavement. Biological: Caused by living things. Roots of trees can tear the ground or buildings apart, but can also keep dirt and rocks in place preventing erosion.
How can we prevent weathering? Weathering can break down materials in a variety of ways. To prevent weathering from happening, we must first know how it is being caused. Physical Caused by Water Caused by Wind Biological Caused by Living Organisms Chemical Caused by Gasses Caused by Minerals Sometimes, physical weathering and chemical weathering can be simultaneous. Ex: Acid Rain
How can we prevent weathering? Nearly all building materials are affected by weathering. In order to prevent your building materials from breaking down, you must understand how the material is most likely going to be broken down (physically or chemically) and then use techniques that stop it from happening. Examples: Brick is a naturally porous material. Because it is porous, wind, water, and roots can easily work their way into a brick wall and slowly break it down. Steel and copper are metals that experience and chemical change and will either rust or patina. If used for structure, the material will slowly loose its structural integrity. If not properly design or cared for, glass will break under a variety of circumstances: strong winds, cracks that wind and rain can worsen, or even manufacturing defaults affected by weathering.
How can we prevent weathering? Some design solutions to combat weathering include: Carefully select and use durable materials that will withstand weathering Coat materials in protective layers Shape your design to direct wind and water away from your structure
How can we prevent weathering? Ex. Galvanization is the process of applying a protective zinc coating to metal in order to prevent weathering such as rusting.
How can we prevent weathering? Ex. Using a self-cleaning glass that has a photo-catalytic and hydrophilic coating on its surface will help to shed water and prevent any possible penetration through the surface of the glass.
Design Advantages of Weathering Aged look in design. Strengthen materials Requires less maintenance Cost effective
Aged Look
Stronger Materials Rust serves to protect weathering steel from further corrosion. Barrier seals the steel against elements that caused them to rust in the first place.
Less Maintenance Bridges built with Corten steel have been known to last up to 120 years with minimal maintenance.
Cost Effective Weathering steel does not require paint which can be a huge added cost.
Cor-Ten Steel Cor-Ten steel is a type of steel that is allowed to be rusted overtime creating a patina that will last and develop over time. The steel will never completely stop rusting, eventually the rust will protect the tell beneath and slow the process Stein Library uses Cor-Ten steel to help the building mimic a look of a geode. A natural rock that has a rough outside but a beautiful crystalline inside. Cor-Ten steel represents the rough outside of the geode The steel honeycomb on the north side represents the crystal structure on the inside
Vertical Gardens and Ivy Vertical gardens give buildings a unique look and can provide fruits and vegetables to consume. Ivy can create patterns on the sides of buildings to enable it to combine with nature. Solar Ivy is solar panels that are scattered on the facades of buildings that replicates the look of ivy in nature
sources http://www.geography.learnontheinternet.co.uk/topics/weathering.html http://www.corten.com/frequently-asked-questions.html http://www.tboake.com/ssef1/weathering.shtml http://en.wikipedia.org/wiki/spontaneous_glass_breakage http://en.wikipedia.org/wiki/galvanization http://www.pilkington.com/north-america/usa/english/products/bp/bybenefit/selfcleaning/how+it+works.htm