Large scale repair work includes replacing or repairing parts of existing structures. It may also involve modifying a structure to change its function or appearance. Examples include adding storage shelves or a screen partition in an apartment building to create a larger living space.
Highway repair projects can generate high levels of airborne crystalline silica. Highway crews perform many tasks that disturb and remove concrete, often during overnight shifts.
1. Removing a section of a structure
Conduct removal operations so as not to interfere with public traffic routes and to minimize damage to the existing structure. When the contract calls for salvage, carefully remove salvaged materials and stockpile them or arrange for their removal as specified. Carefully mark steel members so that they may be matched to replacement materials. When necessary, sound the concrete to determine the extent of the repair area and then carefully remove material within the repair area without damaging the remaining concrete.
Large scale renovations involving more than one house are usually subject to the building standards law, and their specifications need to comply with the current regulations. However, the floor area ratio and height regulations are not applied retroactively to large-scale repair/renovation work.*1 The eaves of a house, for example, can be covered with wooden boards, which are allowed under the law.
2. Repairing a section of a structure
The type of repair required will be determined by the structural engineer and is often based on the original design and material specifications. For example, a steel beam that has deteriorated can be repaired by reinforcing the existing section with similar size and type of bars or with new ones. This will help to restore the original structural integrity of the component. However, replacing a damaged steel member with a new one will require the engineer to perform a detailed design of the replacement structure and prepare a permit application.
When 大規模修繕 concrete, it is important to preserve the strength, weight, aerodynamic characteristics or electrical properties of the original part or structure. This can be done by using materials of the same chemical composition or by replacing the damaged material with a similar component.
To prevent cracking and other damage to the structure, it is recommended that repairs be made in a manner that will distribute the strain over a large area. When repairing a crack, it is also recommended that holes be drilled at the ends of the crack to help control future spreading.
It is also important to ensure that the concrete surface is in a saturated, surface dry (SSD) condition just before placing the repair material. This can be achieved by high-pressure water blasting or other approved methods. Pumping is often used to help place the repair material and is typically started at the bottom of the formwork to push water out of the formwork. Pre-bending reinforcing fabric can be a good way to ensure that corners and re-entrant angles are properly protected. Then, a concrete patch can be placed in the appropriate locations to help protect the reinforcement and provide a strong bond with the repair material.
3. Rebuilding a section of a structure
Rebuilding a section of a structure is a complex task. It requires the coordination of many processes and a large number of people. In addition, it is necessary to plan for the impact of the work on other equipment and structures. The rebuild process is a crucial element of any infrastructure project. Rebuilding can be done in a variety of ways, including replacing or repairing the existing infrastructure and installing new facilities. Rebuilding can also include a combination of these methods, such as adding capacity or changing the shape of an existing structure.
To restore a damaged concrete structure, it is necessary to prepare the area to be repaired. This includes cleaning and removing any loose particles, dirt, or deteriorated concrete that could impair the bond of the repair material. It is important to ensure that the surface of the concrete is a saturated surface-dry condition (SSD) before placing the repair material. This can be accomplished by high-pressure water blasting or other approved methods.
Severely damaged reinforced concrete structures may need to be replaced or the affected section of the structure substituted with new steel. The replacement should be butt welded or lap welded to the existing concrete and anchored with additional stirrup ties, if required.
Renovating a building is a 大規模修繕工事 that involves the remodeling of interior and exterior spaces. The renovation process involves a thorough inspection of the building and careful selection of materials. It is also necessary to consider the safety and security of the inhabitants of the building. The renovation process also involves removing and replacing broken elements, such as windows and doors.
4. Repairing a section of a structure
When repairing a section of a structure, it is important to preserve the strength, weight, aerodynamic characteristics, and electri- cal integrity of the damaged part or structure. This is best accomplished by using the original material or a material approved by the manufacturer. It is also important to minimize stress concentrations by avoiding abrupt changes in cross-sectional areas. It is also a good idea to round corners and smooth and properly contour aerody- namic surfaces.
Generally, the building standards law applies retroactively to construction work that falls within the scope of large scale repair and renovation work. However, there are some exceptions to this rule. For example, buildings that are not located within the area or height restrictions and have obtained special permission may be renovated.
In general, it is best to replace extensively damaged trans- parent plastic rather than trying to patch it up. Even a carefully patched section is not the equal of a new section, both optically and structurally.
For concrete repairs, it is a good practice to thoroughly sound the existing concrete surface to establish the boundary of the repair area. This should include a minimum of 3 inches in both directions. It is also a good practice to remove free (ponded) water from the surface of the existing concrete to achieve saturated surface-dry (SSD) condition just before placing repair material.
