IT strategy for formwork industry

Donghoon Yang

I. Existing processes and business environment:

The first recorded house using above-grade concrete walls in the United States was built in 1844 in Milton, Wisconsin, by tradesman and innkeeper William Goodrich. The house, with its massive load-bearing walls and six-sided three-story tower, remains intact today and serves as a museum. The introduction of two user-friendly concrete construction systems to the United States has provided builders of single-family homes with more choices for the construction of above-grade walls. For decades, home builders throughout Europe have built extensively using the two technologies-insulating concrete form systems and autoclaved aerated concrete-but the systems were not widely available in the United States until after 1990. These concrete systems are now attracting U.S. interest because they provide alternatives to timber construction that combine properties of fire resistance, superior thermal insulation and sound insulation, and are easy to construct.[3, PCA]

Formwork is a temporary structure that is used to construct the permanent reinforced concrete structure. The importance of formwork is easily ignored by temporary existence of it. For example, structural analysis is always required for RC structure whereas that of formwork is neglected in many cases. Though, building cost for formwork including labor and material is usually 60% of RC structure construction.[22 Burd] It is estimated that the cost related to structure is around 25-30% of entire building construction cost. Figure 1, 2 and 3 are cost analysis data from high rise apartment contractor during 1989 – 1993. [21 Yoo] From this statistic of construction cost, the labor cost of formwork is around 17% - 21% from all construction cost including material and labor except overhead cost of contractor’s head quarter.

The result shows in [21, Yoo] might have little different with real situation in U.S concrete home builder’s due to the difference of building type(high rise housing vs private housing), labor cost and industry type, but the general tendency of portion of labor and formwork in entire construction cost would not have significant difference.

The majority of homeowners were likely to build a concrete home if it had a comparable cost to wood in 2002 (52%)—up slightly from 2000 (50%). In 2002, 31% of homeowners were likely to build a concrete home if it cost 2% to 5% more—almost the same as 2000 (30%).[25] Expected market size of the future roughly ranges from 7.5 billion to 16 billion per year. It is based on the 1997 single family housing census and above data.

Table 1 Expected market size

Value of construction work of single family housing / $146,798,768,000
Expected rated of new home built with concrete / 30% - 50%
Portion of concrete formwork cost from construction cost / 17%-21%
Expected market size of the future / Entire single family housing / 5% - 10%
Expected market size of the future / $7.486 million -
$16,030 million

Due to the big portion of formwork in construction industry, there have been attempts to use more efficient formwork in construction. As a result of these efforts, cost efficient system formwork is widely used nowadays. System formwork is made of steel or aluminum frames and coated wood panel. Each system formwork has modular system according to manufacturing company's standard. System formwork manufacturers have their own accessories for tying, cornering, and ending. (ex: clamp, corner form, end form, tie bolt)

Design of formwork for a specific project depends on complexity or type of buildings. Subcontractor's design team designs most of general building, whereas formwork manufacturer's design team designs complex shaped or special type of customized formwork. Design fee of formwork is usually regarded as a part of providing formwork construction or providing formwork to subcontractor/contractor. Fee of formwork material can be included in formwork subcontractor's cost or contractor's cost by projects.

Table 2 Comparison of formwork layout drawing system

TIPOS 4.0 / Design Fast
Dimension / 3D / 2D
Importing translator / DXF, IFC / Yes
Exporting translator / DXF / -
BOM / Yes / Yes
Supported structure / Wall, Slab / Wall
Type of formwork / System formwork / System formwork
Other features / Provide library of all other formworks to AutoCAD
Structural analysis of formwork
Sequence planning

As an industrialized modular product, some system formwork manufacturers use 3D technology to system formwork layout design of wall and slab structure. German based Doka Schalungsteckniker is one of the leading companies in formwork industry. Doka's TIPOS 4.0 makes a 3D design of wall and slab formwork layout and generates BOM. Other formwork companies' system formwork can be supported by this application. Alsina, Meva, Noe, Peri, Sten, and Thyssen-Hünnebeck use the same application with Doka with different formwork and accessory modules. Symons' Design Fast is another application that draws layout of wall formworks and makes BOM. Manufacturer’s intention of developing these applications is to provide convenient tool that can reduce design time and can expand their system’s market share. As the result of applying information rich 3D technology, TIPOS system reduces time to check material, list of accessory and layout itself.

There exist around 20 concrete related associations and organizations in the United States. Dependency of formwork industry results in organization of formwork belonging concrete related organization. Recent consideration of cast in place reinforced concrete as housing construction material made a new association named Concrete Home Council in 2001. It is an alliance of concrete industry system providers, builders, developers, concrete contractors, and concrete industries for the advancement of safe and energy efficient housing. Participating formwork companies are Precise Forms, Dow Chemical Company, Wall-Ties & Forms, Outinord Universal, Durand Forms, and Western Forms. Following table is summary of products.

Table 3 Participating formwork manufacturer of CHC

Precise Forms / Dow Chemical Company / Wall-Ties & Forms / Outinord Universal / Durand Forms / Western Forms
Product / Aluminum formwork,
Vinyl formwork / Sandwich wall with insulation / Aluminum formwork / Steel formwork / Aluminum formwork / Aluminum formwork
Reusability / Al – O
V – X / X / O / O / O / O
Layout Application / - / O
2D / - / - / - / -

Figure 4 is a high level process model of formwork manufacturer. Reusability of formwork and long lasting lifetime of system formwork makes a different type of contract between manufacturer and contractor from other construction material. Contractor can buy or lease formwork. As a result, the formwork manufacturer makes formwork as well as repairs used formwork.

Figure 4 High level process model of formwork manufacturer

II. Available and suitable information technologies

2.1 Possible domain

The overall process of concrete formwork can be broken down to formwork design, fabrication, distribution, placement and stripping process. As mentioned in the first section, formwork erection and stripping process is a big challenging area of cost reduction in the entire construction to the contractor and subcontractor. Cutting down field labor by using cost effective formwork would be one of apparent innovations in the formwork process.

Looking down detailed process of formwork erection reveals anther possibility of construction cost reduction. Concrete wall and slab require specialized opening and details by each part, custom parts and accessories of modularized formwork offered by the manufacturer could be used or site built attachments could are used for modification or adjustment in the site. The modification or adjustment of formwork before erection as well as the mistakes in the formwork has critical impact on the workability of formwork in the site. Custom item built in the site requires different kind of worker in different wage. Controlling one task with different type of worker(carpenter) is not efficient than working with single kind of worker. It is not always possible to eliminate the entire site work for adjusting shape of formwork but it is possible to minimize site work by providing plant built detail attachment.

The formwork should be modified to reflect all the details required by the structure before it is erected in the field to minimize field modification of formwork and to keep the accuracy and tolerance of the formwork. Detailing information of structural concrete is required to be transferred from design team to formwork manufacturer.

More cost efficient formwork process would be gained, when an information rich 3D model of a concrete structure is used as the base to generate formwork design, modification on detail and other information of formwork (BOM, structural analysis of formwork, packing, erection schedule, re-shoring, stripping schedule, cost estimation, plant scheduling and etc)

Formwork manufacturer resides in a different aspect. When client's drawing of structure is transferred in a digital media, formwork manufacturer would quickly generate formwork layout and uses them for estimation.

Within this view point, formwork industry shows different aspect with other industry. The domain that uses information technology is not the most profitable domain by adopting IT technology. IT technology adopted by manufacturer influences productivity of concrete formwork subcontractor’s productivity.

2.2 Applicable IT technology

In general, information rich 3D modeling requires building product model of concrete structure. Formwork layout design package’s importer will take in geometric information (dimension of concrete structure) and procedural information (building sequence, construction joint). Formwork layout design package will help designer to layout formwork, to check structural stability and to detail required custom part and accessory. Construction sequence, BOM, manufacturing drawing, manufacturing information, and packing information will be generated as the result of this process.

Table 4 Applicable IT for concrete formwork

3-D Modeling / Structural Analysis / CAM and Robotics / Manufacturing and ERP / Scheduling
Formwork Layout / O
Structural Analysis / O
Detailing / O
BOM / O
Fabrication / O / O / O
Reused Formwork / O
Erection / O

Possible area of IT for each work domain can be summarized as Table 3. Many of IT technology are implemented in the current available system (Doka TIPOS 4.0). Tipos system can handle most of applicable area except detailing part (custom design part). A system that can handle detailing of formwork so as to reduce field modification is not provided until now, which is expected to enhance productivity of formwork installation and stripping on the site. Detailing design is the key area for immediate IT technology adaptation for formwork industry.

III. A framework target plan, including assessment of potential benefits:

The viewpoint of contractor and manufacturer was mixed in the previous section. The benefit of using system formwork and shortening layout design time are viewed most beneficial part. IT adoption makes cost reduction in time and labor by reducing site work on formwork modification and adjustment of concrete structure in the construction site. It also reduces the time and labor in layout design and provides more accurate estimation to the manufacturer.

Reorganizing process model showed different aspect of formwork industry. There are two major changes in the formwork manufacturer's side, which would bring about significant change of the all the process of formwork manufacturing industry. Overall process of formwork manufacturer would be changed from Estimate -> Contract -> Design -> Supply to Design -> Estimate -> Contract -> Supply.

First major change is when the contract is made in the process. In current process, contract is signed after the estimation is finished. This cost estimation is not based on the detailed formwork layout. It is usually based on rough layout design. The detailed design will be done after the contract, and would have changes in design and quantity of material. When IT is used in designing formwork layout, detailed formwork layout can be generated earlier than the contract and cost estimation will be based on the final drawing of formwork layout and quantity.

Second change lies in the distribution of formworks. Current distribution of formwork uses: 1. deliver to site, 2. use formwork, 3. return to plant, 4. check condition, 5. repair, 6. move to warehouse. If an inspector goes to the construction site and checks the missing part and reusability, the information of the formwork used in the site is updated to the manufacturer's plant inventory maintenance database, the manufacturer can use this information for providing updated information of current inventory to formwork layout design and estimation. Formwork with barcode or RF tag provides more detailed information by each formwork piece. Other effect of input data from the site inspector is that formwork distribution can be changed from warehouse-to-site to site-to-site as long as there is available succeeding site. Plant scheduling and control database gets data from plant inventory database and decides dispatching of formwork to next construction sites based on real data rather than planned data on the contract. This allows formwork manufacturer to downsize warehouse and increase turnover ratio of inventory. Plant scheduling and control database can provide information to the layout design package and layout design can be based on available inventory at the moment when new project starts.

Figure 5 IT adopted high level process model of formwork manufacturer

Reference

1. Concrete Homes Council, http://www.concretehomescouncil.org/

2. Concrete Homes, http://www.concretehomes.com/

3. Portland Cement Association, http://www.cement.org

4. Precise Forms, http://www.preciseforms.com

5. Dow Chemical Company Inc., http://www.t-mass.com

6. Wall-Ties & Forms, Inc., http://www.wallties.com

7. Outinord Universal, http://www.outinord-americas.com

8. Durand Forms http://www.durandforms.com

9. Western Forms, http://www.westernforms.com

10. Advance Concrete Form, Inc. http://www.advanceconcreteform.com/

11. Duraforms Inc, http://www.duraform.com/

12. EFCO-Forms, http://www.efco-usa.com

13. Gate & Sons, http://www.gatesconcreteforms.com

14. ICS 3-D Panelworks, Inc., http://www.3-dpanelworks.com

15. SCI Global, http://www.sciglobal.com

16. Symons Corporation, http://www.symons.com

17. Tuf-n-Lite, http://www.tuf-n-lite.com

18. Wall-Ties & Forms, Inc., http://www.wallties.com

19. Western Forms, Inc., http://www.westernforms.com

20. Williams Form Engineering Corp., http://www.williamsform.com

21. Yoo Yongmin, Cost analysis of Apartment housing in Korea, 1993

22. M. K. Hurd, Formwork for Concrete, 1996

23. Artifice, Inc., http://www.artifice.com

24. 3D Home Architect, http://www.broderbund.com

25. Concrete Homes newsletter, Sept. 2002

26. US census bureau, 1997 Economic census, Single family housing construction

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