Formwork for Concrete: A Comprehensive Guide by M.K. Hurd
- Who is Mary Krumboltz Hurd and what is her book about? - What are the main topics covered in the book? H2: Materials and accessories for formwork - What are the common materials used for formwork and their properties? - What are the accessories that help in formwork construction and operation? - How to select and use materials and accessories for different types of formwork? H2: Form design principles and methods - What are the factors that affect form design and how to calculate them? - What are the basic design principles for formwork components such as lumber, plywood, steel, etc.? - What are the methods for designing formwork for various structural elements such as beams, slabs, columns, walls, etc.? H2: Building and erecting the formwork - What are the steps involved in building and erecting formwork for concrete? - What are the best practices for handling, storing, assembling, bracing, and aligning formwork? - How to ensure safety and quality during formwork construction and operation? H2: Using and removing the forms - How to prepare and place concrete in formwork and what are the effects of vibration and temperature on formwork? - How to monitor and control lateral loads and deflections on formwork during concrete placement? - How to remove formwork safely and efficiently without damaging the concrete or the forms? H2: Special types of formwork - What are the advantages and disadvantages of prefabricated forms and forming systems? - How to design and use formwork for complex shapes such as shells, domes, folded plates, etc.? - How to create architectural forms with special finishes, textures, colors, etc.? H1: Conclusion - Summarize the main points of the article. - Emphasize the benefits of reading Formwork for Concrete by Mary Krumboltz Hurd. - Provide some resources for further learning. H2: FAQs - Answer some common questions related to formwork for concrete. # Article with HTML formatting Introduction
If you are involved in concrete construction, you know how important formwork is. Formwork is the temporary structure that supports fresh concrete until it hardens and acquires its shape and strength. Formwork not only affects the quality, cost, and schedule of a project, but also the safety of workers and the environment.
Formwork For Concrete By Mary Krumboltz Hurd.pdf
But how do you design, build, use, and remove formwork effectively and efficiently? That's where Formwork for Concrete by Mary Krumboltz Hurd comes in handy. This book is a comprehensive guide on formwork for concrete that covers everything from materials and accessories to design principles and methods to construction practices and special applications.
Mary Krumboltz Hurd is a civil engineer with over 40 years of experience in concrete construction. She has been involved in numerous projects involving bridges, buildings, dams, tunnels, power plants, etc. She has also been a member of ACI Committee 347-Formwork for Concrete since 1974 and has contributed to several publications on formwork.
In this article, we will give you an overview of some of the main topics covered in Formwork for Concrete by Mary Krumboltz Hurd. We will also provide some examples and tips to help you apply the knowledge from this book to your own projects.
Materials and accessories for formwork
The first step in formwork construction is to select the appropriate materials and accessories for your project. The choice of materials depends on several factors such as availability, cost, durability, strength, stiffness, weight, compatibility, etc.
The most common materials used for formwork are wood, steel, aluminum, and plastic. Each material has its own advantages and disadvantages. For example, wood is cheap, easy to work with, and adaptable, but it is also susceptible to moisture, decay, and fire. Steel is strong, rigid, and reusable, but it is also heavy, expensive, and prone to corrosion. Aluminum is light, corrosion-resistant, and easy to assemble, but it is also costly and has low stiffness. Plastic is versatile, durable, and resistant to weathering, but it is also difficult to join and has low strength.
The accessories for formwork are the components that help in the construction and operation of formwork. They include fasteners, connectors, clamps, ties, braces, shores, jacks, etc. These accessories should be selected and used according to the design specifications and the manufacturer's recommendations. They should also be inspected and maintained regularly to ensure their proper functioning.
Some tips for selecting and using materials and accessories for formwork are:
Use materials that are suitable for the type and duration of formwork. For example, use steel or aluminum for long-term or repeated use of formwork, and use wood or plastic for short-term or single use of formwork.
Use materials that are compatible with each other and with the concrete. For example, avoid using materials that may cause staining, discoloration, or chemical reaction with the concrete.
Use materials that are easy to handle, transport, store, and assemble. For example, use prefabricated panels or modular units that can be easily moved and erected on site.
Use accessories that are designed and tested for the intended load and service conditions. For example, use ties that can resist the lateral pressure of concrete without failure or leakage.
Use accessories that are easy to install and remove without damaging the formwork or the concrete. For example, use snap-off ties or cone bolts that can be easily broken off or unscrewed after concrete hardening.
Form design principles and methods
The next step in formwork construction is to design the formwork according to the structural requirements and the architectural features of the project. The design of formwork involves calculating the loads, stresses, deflections, and dimensions of the formwork components and ensuring their safety and stability.
The factors that affect form design include the weight of concrete and reinforcement, the lateral pressure of concrete during placement and vibration, the wind and earthquake loads on the formwork structure, the temperature variations and shrinkage effects on the concrete and formwork materials, etc.
The basic design principles for formwork components are based on the material properties and the structural behavior of the components. For example,
Lumber should be selected according to its grade, species, moisture content, size, etc. It should be cut to length and width with square ends and edges. It should be supported at regular intervals to prevent sagging or buckling.
Plywood should be selected according to its type, thickness, grade, etc. It should be oriented with its face grain perpendicular to the supports. It should be fastened with nails or screws at specified spacing to prevent warping or splitting.
Steel should be selected according to its shape, size, grade, etc. It should be fabricated with accurate dimensions and angles. It should be welded or bolted with proper connections to ensure rigidity and strength.
The methods for designing formwork for various structural elements depend on the shape, size, span, load distribution, support conditions, etc. of the elements. For example,
Beam or girder forms should be designed to support the dead load of concrete and reinforcement plus a live load of at least 50 psf (2.4 kPa). They should also be designed to resist bending stresses due to self-weight and lateral pressure of concrete.
Slab forms should be designed to support the dead load of concrete and reinforcement plus a live load of at least 75 psf (3.6 kPa). They should also be designed to resist deflection due to self-weight and lateral pressure of concrete.
Column forms should be designed to support the dead load of concrete and reinforcement plus a live load of at least 100 psf (4.8 kPa). They should also be designed to resist buckling due to self-weight and lateral pressure of concrete.
Wall forms should be designed to support the dead load of concrete and reinforcement plus a live load of at least 150 psf (7.2 kPa). They should also be designed to resist bulging due to self-weight and lateral pressure of concrete.
Building and erecting the formwork
The third step in formwork construction is to build and erect the formwork on site. This step requires careful planning, supervision, and coordination of labor, equipment, and materials. It also requires following the best practices for safety and quality during formwork construction and operation.
Some of the steps involved in building and erecting formwork for concrete are:
Cut and fabricate the formwork components according to the design drawings and specifications. Use proper tools and techniques to ensure accuracy and quality.
Transport and store the formwork components on site in a safe and orderly manner. Protect them from damage, moisture, fire, theft, etc.
Assemble the formwork components on site or prefabricate them in a shop or yard. Use appropriate fasteners, connectors, clamps, etc. to join the components securely.
Place and align the formwork components on the supports or foundations. Use braces, ties, shores, jacks, etc. to adjust and stabilize the formwork.
Check and verify the dimensions, levels, plumbness, alignment, etc. of the formwork before placing concrete. Make any necessary corrections or adjustments.
Some tips for building and erecting formwork for concrete are:
Follow the manufacturer's instructions and recommendations for using prefabricated forms or forming systems.
Use proper lifting and handling equipment to move and place the formwork components safely and efficiently.
Use adequate temporary supports and bracing to prevent collapse or failure of formwork during erection or adjustment.
Use suitable surface treatments or coatings to protect the formwork materials from moisture, corrosion, adhesion, etc.
Use proper safety measures and precautions to prevent accidents or injuries during formwork construction and operation.
Using and removing the forms
The fourth step in formwork construction is to use and remove the forms after placing concrete. This step requires careful preparation, monitoring, and control of concrete placement and curing. It also requires following the best practices for safety and quality during formwork use and removal.
Some of the steps involved in using and removing forms for concrete are:
Prepare the forms for concrete placement by cleaning them from any debris, oil, water, etc. Apply suitable release agents or bond breakers to prevent adhesion of concrete to forms.
Place concrete in forms according to the specified methods and procedures. Use proper equipment and techniques to transport, distribute, consolidate, and finish concrete.
Vibrate concrete in forms according to the specified methods and procedures. Use proper equipment and techniques to avoid overvibration or undervibration of concrete.
Monitor and control the lateral pressure of concrete on forms during placement and vibration. Use proper equipment and techniques to measure and reduce the pressure if necessary.
Cure concrete in forms according to the specified methods and procedures. Use proper equipment and techniques to maintain adequate temperature, moisture, strength, etc. of concrete.
Remove forms from concrete according to the specified methods and procedures. Use proper equipment and techniques to detach, strip, lower, transport, clean, store, etc. forms without damaging them or the concrete.
Some tips for using and removing forms for concrete are:
Follow the manufacturer's instructions and recommendations for using prefabricated forms or forming systems.
Use proper sequencing and timing of concrete placement to avoid cold joints, honeycombs, cracks, etc.
Use proper sequencing and timing of form removal to avoid premature or delayed stripping of forms.
Use adequate shoring or reshoring of multistory structures to prevent excessive deflection or cracking of slabs or beams due to load transfer.
Use proper safety measures and precautions to prevent accidents or injuries during form use and removal.
Special types of formwork
The final step in formwork construction is to use special types of formwork for complex or unique projects. These types of formwork may require special design, materials, methods, or equipment to achieve the desired results.
Some of the special types of formwork are:
Prefabricated forms and forming systems: These are forms that are manufactured off-site and delivered ready to use on site. They may be made of steel, aluminum, plastic, or composite materials. They may have standard or customized shapes and sizes. They may also have integrated features such as connectors, ties, braces, etc. They offer advantages such as speed, quality, reusability, and adaptability.
Formwork for complex shapes: These are forms that are designed and built to create concrete structures with curved or irregular shapes such as shells, domes, folded plates, etc. They may be made of flexible or rigid materials such as fabric, wood, metal, etc. They may also use special techniques such as pneumatic forming, cable-stayed forming, etc. They offer advantages such as aesthetics, functionality, and innovation.
Architectural forms: These are forms that are designed and built to create concrete structures with special finishes, textures, colors, patterns, etc. They may be made of various materials such as wood, metal, plastic, rubber, etc. They may also use special treatments or coatings such as form liners, retarders, stains, etc. They offer advantages such as beauty, durability, and sustainability.
Some tips for using special types of formwork are:
Follow the manufacturer's instructions and recommendations for using prefabricated forms or forming systems.
Use proper analysis and modeling tools to design and optimize formwork for complex shapes.
Use proper testing and inspection methods to verify the performance and quality of architectural forms.
Conclusion
In this article, we have given you an overview of some of the main topics covered in Formwork for Concrete by Mary Krumboltz Hurd. We have also provided some examples and tips to help you apply the knowledge from this book to your own projects.
Formwork for Concrete is a comprehensive guide on formwork for concrete that covers everything from materials and accessories to design principles and methods to construction practices and special applications. It is a valuable resource for anyone involved in concrete construction.
If you want to learn more about formwork for concrete, we recommend you to read Formwork for Concrete by Mary Krumboltz Hurd. You can also find more information and resources on the website of the American Concrete Institute (ACI).
FAQs
Here are some common questions related to formwork for concrete:
What is the difference between formwork and falsework?
Formwork is the temporary structure that supports fresh concrete until it hardens and acquires its shape and strength. Falsework is the temporary structure that supports formwork or other structures during construction.
What are the factors that affect the lateral pressure of concrete on formwork?
The factors that affect the lateral pressure of concrete on formwork include the rate of placement, the temperature of concrete, the consistency of concrete, the height of placement, the vibration of concrete, etc.
What are the advantages and disadvantages of using steel formwork?
The advantages of using steel formwork are that it is strong, rigid, reusable, and easy to assemble and dismantle. The disadvantages of using steel formwork are that it is heavy, expensive, and prone to corrosion and thermal expansion.
What are the advantages and disadvantages of using fabric formwork?
The advantages of using fabric formwork are that it is flexible, lightweight, and adaptable to complex shapes and surfaces. The disadvantages of using fabric formwork are that it is difficult to join and seal, and it may require special equipment and skills to use.
What are the safety precautions to be followed during formwork construction and operation?
Some of the safety precautions to be followed during formwork construction and operation are:
Use proper personal protective equipment such as gloves, helmets, boots, etc.
Use proper lifting and handling equipment to move and place formwork components safely and efficiently.
Use adequate temporary supports and bracing to prevent collapse or failure of formwork during erection or adjustment.
Use proper safety measures and precautions to prevent accidents or injuries during formwork use and removal.
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