Monday, June 13, 2011

NCSU Engineering Camp 2011: Civil Engineering part 1

Recently I participated in a very exciting educational opportunity; I was able to take yet another trip to NC State University for a summer Civil Engineering Camp. I attended this camp for the purpose of enriching my understanding of architecture beyond the design standards. For example an architect has to understand and allocate the right kind of concrete for a building; architects have to understand what civil engineers do in order to design buildings for the civil engineers to engineer, just as civil engineer have to understand a construction worker's work in order to know how to best plan the construction of a building. For me, experiencing Civil Engineering means going back to the roots of what architecture used to be: engineering the best possible structure. Design can only go so far before engineering and physics makes it impossible. The Civil Engineering Camp was a stay in camp in which I attended four full days of intensive study into the works of Civil engineers. During these four days, I was taught the fundamentals of making concrete, hydraulics, surveying, water filtration and bridge building.

Day 1: Fundamentals of Concrete making
Our first day was dominated by a tutorial on how to engineer concrete. Basically, concrete is a mixture of several components; water, sand and gravel along with cement. Despite people's perceptions, cement is not concrete. Cement is the binding agent that allows other components such as water, sand and gravel to be able to bind to each other. In such a reaction, water is the catalyst for such a reaction. the right amount of sand, gravel must be added for maximum strength. Because gravel is very large, it has many air holes which would decrease the strength of the concrete and exacerbate the problems of expansion and contraction during the transition from warm to cold and vice versa. To solve this fundamental problem, sand is implemented in order to allow for the closing up of these air holes. However, the right amount of mixture of sand and gravel must be achieved; gravel provides most of the strength in the concrete, but not enough sand may decrease the maximum effectiveness of the concrete. Also, if there is too much sand, the concrete would become too weak. As in chemistry, more of any singular component doesn't necessary yield a bigger or stronger reaction; in this case more of any singular component in a concrete mixture doesn't necessary yield a stronger concrete. Not only strength is a consideration, but also the cost. Concrete is a relatively simple composite; however to use it en mass an engineer must be able to minimize the cost to its barest minimum while keeping it's tensile strength intact. This concept is also very important for architects, as their designs must optimize to reduce costs, and knowledge of civil engineering allows for even more reduced costs as micro management could lead to big savings cumulatively.

Day 1: Making the concrete
My engineering group decided on something like a 16% water mixture into our concrete mix. Our proportion of sand is greater than gravel. However, as we learned while mixing the concrete, we added too much water, making the concrete mixture extremely unstable. In order to compensate for having too much water, we added extra sand and gravel in order to balance our mixture. Afterwards, we conducted something called the slump test, where we measure the slump or vertical differential of the concrete mixture after pouring it into a metal trapezoidal cylinder. We measured how much the concrete mixture fell from the tip of the trapezoidal cylinder. A good concrete mixture always has slump because it indicates that the concrete mixture could grow in size and strength. If a concrete mixture has too little slump, it indicates that the concrete mixture doesn't have much growth left.

(A weak concrete mixture with too much gravel)

Day 1: Curing
Curing is the process in which a concrete mixture is left in some sort of box where it undergoes extensive chemical reactions where the cement reacts with the water, sand and gravel . This process essentially allows the concrete to increase in strength. Typically the curing process takes approximately 28 days to achieve maximum strength. However, due to the limited time that our camp as allocated, we have only about 4 days to allow the concrete to undergo curing. Despite the shortened time, concrete mixtures tend to grow in strength in a logistical growth curve manner; growing exponentially at first then slows its rate of growth after the initial period of curing is over.

Day 1: Surveying skills
The second half of the workshop was devoted to teaching us the basics of surveying. Surveying is an extremely important skill that Civil Engineers, Architects and Construction workers have to learn how to do. Construction, design and engineering on ground requires a through understanding of the topography on which such buildings are built upon. For example, the building must be given enough support if it is to be placed on a hill. Also, any differences in depth and height must be accounted because the foundation must be set according to depth and elevation. Understanding the field of construction is important not only for practical reasons, but also for aesthetic reasons. Buildings can be placed protruding from a hill for an architectural statement, or could surround an valley. Normally, surveying an area consisted of N, W and Z components (x, y, z), but for the purposes of our surveying workshop, we used only the N and W components. Surveying consists of a set area in which the surveying is to be done. Basically, surveying consists of finding an area. There are three ways to survey an area. Two of which are merely crude estimates. Using a person's pacing as a measuring tape, we follow along the path of the surveyed area and measured the area in the lot by splitting it into regular geometric shapes.
The second consists of measuring the sides with a measuring tape. The third method involves the use of a surveying machine that measures the distance by sending a laser beam to a mirror at the other end of the point which is then reflected back in order to calculate the distance between the machine and the mirror. However, the first two methods are not productive, as the surveyed area could have highly irregular shapes that would make using pacing and measuring tapes awkward. Instead, the use of the surveying machines are a must for standard surveying.


Overview:
The first day was an intensive course in the field of engineering, as the mystery behind concrete is unveiled; my idea and perception of concrete as a building material has changed. Learning about the complexity of concrete has been truly enlightening because I realize how it relates to architecture and the various applications it could have. What if we could reprocess concrete back into its components or engineer an extremely efficient concrete for construction; imagine it's effects on architecture? To me, it means a lot of design options to create a better building.

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