WEEK 5 Learning Loop Wall Systems
Studio Structural Systems: Oval Pavilion Frame and Foundation
Glossary Appendix
LEARNING LOOP Walls Walls are the vertical constructions of a building that enclose, separate, and protect its interior spaces. Walls might be loadbearing structures to support imposed loads from floors or roofs and might consist of a framework of columns and beams. Exterior Walls acts as a protective shield for the interior spaces. It holds of against weather conditions and disturbances from outside the structure.
Concrete and Masonry Bearing Walls • Noncombustible construction • Strong Compression • Requires reinforcements to handle tensile stresses
Board-and-batten plywood Ribbed texture formliner Bushhammered surface Ribbed surface bushhammered
Concrete walls can be pre-casted or casted on site.
CONCRETE MASONRY Concrete Walls The formwork can be custom built and prefabricated. What is essential is its ability to be able to maintain position and shape. May serve as bearing walls to support loads from above.
Interior Walls or partitions divide the interior parts of the building. These kinds of wall may be either structural or nonloadbearing.
Concrete Columns are designed together with vertical and lateral reinforcements. Usually it is casted with concrete beams.
FRAMING
Concrete Surfaces can be made with various methods; • Exposed fine aggregates • Exposed coarse aggregates • Sandblaster plywood
The Structural Frames of wall systems can be concrete frames, steel frames, or timber frames.
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Masonry Walls Consisted of modular building blocks bonded together with mortar to form walls that are durable, fire-resistant, and structurally efficient in compression. • Mortar is a bonding agent made of cement or lime or both with sand and water Can be divided into: • Solid Masonry (solid or hollow) • Grouted Masonry (the interior joints are filled with grout) Reinforcements use steel bars placed inside the joints or cavity.
Masonry Columns and Arches utilizes the compressive strength of brick and stone. Materials Expansion and Contraction depends on change in temperature and moisture content. Masonry Joints: • Expansion Joints: accommodate moisture expansion and provide lateral stability • Control Joints: accommodate shrinkage and dries after construction
Metal and Wood Stud Walls • Cavities in the frame can accommodate thermal insulation, vapor retarders, and mechanical distribution • Can be made in variation • Made fire-resistance • Can be assembled on and off site • Flexible in workability STEEL Steel Columns are formed by steel studs and steel forming sheet or strip steel. It can be cut and assembled easily. Steel columns are lightweight, noncombustible, and damp-proof. Steel Framing supports the walls as it takes on the load distribution systems and makes the walls non-loadbearing. WOOD Wood Columns can be solid, built-up, or spaced. Factors that affect wood framings are; lumber species,
structural grade, modulus of elasticity, and compressive, bending, and stress value. Platform Framing or lightwood frame are usually studded and each storey rest on one another. Post-and-Beam Framing uses vertical posts and horizontal beams to carry floor and roof loads.
STUDIO The task on Week 5 Studio session was to make a scaled-model of a part the Oval Pavilion in groups of 3-5. Materials used: • Styrofoam • Recycled Cardboard • Balsa Blocks • Cutter • Glue Gun Materials Evaluation In the real-life structure, the Oval Pavilion is made up of an overlapping and side-by-side use of concrete, steel beams and columns, and timber or plywood sheets. On the scaled model, Styrofoam, balsa, and cardboard were used. Some of the reasons why such materials are chosen are: • Easy to be used • Hard and rigid, able to withstand its form and position.
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Cost-effective Lightweight
Cardboard and Styrofoam are used to construct the foundation part of the modeled structure. Even as a small model, the foundation must be able to deal with loads from the above structure, under compressive forces and soil pressure. Balsa blocks were carved to form columns representing steel columns. Balsa is a rigid material thus it can withstand loads from the frame place above.
Styrofoam was used in making the framework of the canopy. It is the material with the least mass thus it will not give as much downwards force as the other materials. The scaled model was made in a 1:20 scale comparing to the original size of the actual building.
Design and Plan Based on the design plan, grid and numbering systems gives easy access and guide to parts of the Oval Pavilion that is going to be modeled.
Load Transfer of the Canopy Framework
Based on the Ground Floor Plan, the canopy area was bounded with grid number 3-7, being the canopy located right in front of the main function room area.
Side View
The frame structure of the canopy is designed in an irregular pattern, especially the horizontal section of the canopy. The frame of the canopy is made up of more than 1 part. It is based on a single frame that span to both end of the canopy shape, why other frames are put ‘overhanging’ or partly indicate a cantilever-shape. It was designed to maximize covering up spaces of the frontal part of the Oval Pavilion, its shape is mostly based on aesthetic reasons.
The foundation of the ground floor was designed as a ’second’ with a basement level underneath. The beams are designed to span across the whole width of the base of the canopy to the walls/ entrance to the function room. The width of the foundation span longer than the canopy. In such there are still open spaces that are exposed, although nit much.
Step-by-Step Process
Foundation
1.
The foundation was made of a cardboard sheet (slab). Underneath it is supported by 4 pieces of cardboard and 3 pieces of Styrofoam pieces representing beams that span across the width of the sheet. Beams were placed underneath the slab. With the cardboard pieces (beams) underneath the orientation of the whole structure was tilted.
2.
3.
This is one slight-back disadvantage, as there is supposedly a basement level underneath the foundation, which in this case is not modeled. Our model only previewed the first level and the canopy.
In addition to that additional shorter beams (noggins) was places between the longer beams. The reason of this was to mainly prevent lateral movement.
Frame The frame superstructure is made up of two main parts, the canopy framework and the columns supporting the framework.
The original design of the beams underneath the slab was for steel beams underneath the concrete floor.
Above the columns rest an irregular shape framework of the canopy. The framework is solely based on the design in the construction environments handbook.
Construction of the canopy is entirely frame construction. As stated above, the framework is in an irregular pattern, indicating the presence of a truss system with of unusual pattern. The load is then transferred to the vertical part of the frame superstructure; the columns, and then carried down to the ground.
The canopy framework is made supported with only three columns. The framework is made with balanced distribution of the weight and hanging parts / cantalevers. In the actual building, the framework is covered up with large timber (plywood) sheets.
Connection and Joints
Comparison with Other Groups
On the scaled model, al of the joints and intersection points of each of the materials were connected using glue gun.
1.
Glue gun can be considered very efficient as in liquid form the glue can be situated to cover all the intersection points and then dries in a short amount of time.
This group made a 1:20 scaled model of the central support of the canopy area. Instead of a column, a structure is used. The support structure is a frame construction. As in any other frame construction the load is transferred through the ‘beams’ and ‘columns’ of the structure to the ground. Truss systems can also be applied, the axial load of the upper part; the canopy, is transferred to the ground.
2.
The construction of this group’s 1:20 is also based on frame construction. Like an ordinary frame, it consisted of beams and columns and plied truss system for load distribution. Different from other models, the frame structure that this group made seemed to be the most usual structure, with horizontal beams and vertical columns in a usual shape.
Balsa is used to represent steel beams and columns in the scaled model. The finish product of the model itself seemed stable and rigid enough to withstand its form.
GLOSSARY APPENDIX 1
Stud: A vertical framing member in a building's wall of smaller cross section than a post 2
Nogging: Also known as brick nog or beam filling. It is a construction technique in which bricks are used to fill the vacancies in a wooden frame. The walls then may be covered with tile, weatherboards or rendered. 3
Lintel: A horizontal supporting member, installed above an opening such as a window or a door, that serves to carry the weight of the wall above it. Lintels can be a load-bearing building component, a decorative architectural element, or a combined ornamented structural item. It is often found over portals, doors, windows, and fireplaces. 4
Axial Load: A force administered along the lines of an axis. Axial load is also known as longitudinal loads.
Transverse loads are perpendicular to the longitudinal length of the member. 5
Buckling: In a compression member or compression portion of a member, the load at which is bending progresses without an increase in the load. It is the collapse of a slender vertical element, which has been subjected to compression, leading to a sudden sideways deflection. 6
Seasoned Timber: Reducing the moisture content of wood before its use. It is also known as seasoning lumber or wood seasoning. 1 Stud. 3 March2014. Retrieved from http://en.wikipedia.org/wiki/Wall_stud 2 Brick Nog. 19 March 2014. Retrieved from http://en.wikipedia.org/wiki/Brick_nog 3 Lintel. 27 August 2014. Retrieved from http://en.wikipedia.org/wiki/Lintel_(architecture). Retrieved from http://www.dictionaryofconstruction.com/definition/lintel.ht ml 4 Axial Load. Retrieved from http://www.answers.com/Q/What_is_axial_loading 5 Buckling Load. Retrieved from http://encyclopedia2.thefreedictionary.com/Buckling. Retrieved from http://www.dictionaryofconstruction.com/definition/buckling -load.html 6 Wood Drying. 30 August 2014. Retrieved from http://en.wikipedia.org/wiki/Wood_drying