Architects and Engineers

New Actors Architects are building designers. They are both artists of conceptions and delineators. The schooling for architects does not exist in America before the 2 nd half of the 19 th century. Early architects train in Europe, principally the Ecole des Beaux Arts in Paris American Institute of Architects. Professional organization. Focus upon design. Engineers create structures using principles of science. Design is secondary to the ability of the structure to functionally meet the needs of the application. Engineers may create structures without architects, such as towers, bridges, tunnels. Rensselaer Institute in Troy, New York, first offered a degree in civil engineering in 1835

Beaux Arts 1. Julien Guadet codified the Beaux-Arts principles as seven: a. Investigation of the proper expression for a building b. site location, climate always modify expression c. Simply constructible compositions d. truthful architectural compositions-no shams e. perceivable visual strength in the structure f. easy admittance of air and light g. composition proceeds by necessary compromises

Curtain wall construction

Terra cotta St Louis, glazed terra cotta

Structural Clay Tile Hollow body clay tile began to be used as a fire block in as early as the 1850s, however, its real surge in use came at the end of the 19th century. 1. Tile is classified by its density (hard, semi-porous, porous) and as glazed or vitrified. a. Glazed tile produces a glass surface over the exterior. b. Vitrified tile is fired at such a high temperature that the materials begin to fuse. It is used for exterior activities. 2. Porous tile is created by introducing combustible materials into the clay which are consumed by the firing process. 3. Preservation Brief #30, “The Preservation and Repair of Historic Clay Tile Roofs.” By Anne E. Grimmer and Paul K. Williams. B. Clay tile blocks are used for structures, usually not more than three stories in height. 1. Glazed tiles were used extensively for silos and agricultural buildings in the 1920s and 1930s because of their fire resistance, and the insulation value. 2. Often clay tiles are used as in-fill with steel frames or between concrete piers. Rath Packing Company, Waterloo, Black Hawk County, Iowa.

Clemson University, Agriculture Building

605 Lewis Street, Fredericksburg

Wainwright building

Concrete Concrete is an artificial, stone-like building material made by combining cement with aggregate and adding sufficient water to cause it to set and bind the materials together. Concrete is a mixture of cement (usually Portland cement) and stone aggregate. When mixed with a small amount of water, the cement hydrates form microscopic opaque crystal lattices encapsulating and locking the aggregate into a rigid structure. Typical concrete mixes have high resistance to compressive stresses (about 4,000 psi); however, any appreciable tension (e.g. due to bending) will break the microscopic rigid lattice resulting in cracking and separation of the concrete. For this reason, typical non- reinforced concrete must be well supported to prevent the development of tension. Portland cement is a hydraulic material which consists of at least two-thirds by mass of calcium silicates (3CaO.SiO 2 and 2CaO.SiO 2 ), the remainder consisting of aluminium- and iron-containing compounds.

Reinforced concrete Concrete in which a material with high strength in tension, such as steel is placed. The composite material, reinforced concrete, resists compression but also bending, and other direct tensile actions. A reinforced concrete section where the concrete resists the compression and steel resists the tension can be made into almost any shape and size for the construction industry. What gives reinforced concrete its advantage? First, the coefficient of thermal expansion of concrete is similar to that of steel, eliminating internal stresses due to differences in thermal expansion or contraction. Second, when the cement paste within the concrete hardens this conforms to the surface details of the steel rebar, permitting any stress to be transmitted efficiently between the different materials. The alkaline chemical environment provided by calcium carbonate (lime) causes a passivating film to form on the surface of the steel, making it much more resistant to corrosion than it would be in neutral or acidic conditions. Steel is considered non-reactive in atmospheres where the ph is 9.5 or higher.