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Codes and standards regulate formwork construction

Compliance with the rules is a necessary first step to safety

Late last year part of a freshly poured hammerhead pier cap and its supporting formwork collapsed in Malaysia, killing five workers and injuring three others. Union officials threatened to sue the highway authority and the con tractor for applying "unusual pressure" on workers to rush com pletion of the bridge before July 1985. Hurry, hurry, hurry . . . speed is the name of the game. And financial p re s s u res on the contractor to get the job done faster all too often result in safety being reduced to a bare minimum, or sometimes below acceptable levels. That is why we have codes and standards which try to assure at least the minimum performance necessary for safety. As far back as the days of ancient Babylon builders have been held responsible not only for the quality of their work but for its safety too. Fortunately rules have changed some since 1750 B.C. when the Code of Hammurabi proclaimed: If a builder built a house for a man and did not make its con struction firm, and the house which he has built collapsed and cause d the death of the owner of that house, the builder shall be put to death. Financial disaster instead of sudden death may be the consequence in the modern world. Certainly the losses in time and money that go along with construction mishaps are strong motivators for safe activi-

ty. In spite of a movement today to i n vo l ve the design professionals-- architects and engineers--in the construction process, it does not appear that this will relieve the builder of his basic responsibility.

Relevant national standards

The starting point in coping with codes and standards is to be aware of what they are and what they say. In the United States formwork builders and designers, project planners, and managers are subject to various state and local code requirements for formwork, as well as to a body of national regulations. There are four documents which have established national applicability for formwork safety: · Part 1926, Subpart Q of the federal Construction Safety and Health Regulations (OSHA) · The American Concrete Institute (ACI) "Building Code Requirements for Reinforced Co n c re t e." Chapter 6 deals with form w o rk , embedded pipes, and construction joints. · The American National Standards Institute (ANSI) A10.9, "Concrete and Masonry Wo rk -- Safety Requirements" · The ACI 347-78 standard, "Recommended Practice for Concrete Formwork" The provisions of these documents are not totally consistent, and their periodic revisions are not coordinated. So, if your work is subject to two or more of these regulations, it must be kept in mind that comply-

ing with one set of rules in no way permits you to violate the more stringent provisions of another one. For example, if one regulation says design for 50 pounds per square foot construction live load and another says 20 pounds, use the 50 pounds per square foot and satisfy both. The first two of the regulations listed above, ACI 318 and OSHA Subpart Q, are legally binding in many areas. The ANSI standard and the ACI formwork standard are more detailed voluntary consensus documents that define much of the state-of-the-art technology on which safe construction practices are based. ACI 347 is further supported in this effort by the book, Formwork for Concrete, which explains how to comply with many of the ACI and other safety recommendations.

OSHA regulations

The most widely known federal regulation for concrete construction safety is given in Part 1926, Subpart Q of the Occupational Safety and Health Administration (OSHA) "Safety and Health Regulations for Co n s t ru c t i o n ." Subpart Q itself is brief--not much longer than two pages in this magazine. Howe ve r, in addition to setting down a few specific rules, it incorporates by reference ANSI A10.9-1970 "Safety Requirements for Co n c re t e Construction and Masonry Wo rk ." A10.9 in turn references not only the ACI 347-68 standard, but also the ACI book, Formwork for Concrete, as well as safety regulations of the Scaf-

folding, Shoring, and Forming Institute. Since the 1972 issuance of the OSHA regulations, both the ACI 347 and ANSI A10.9 have been revised, but the letter of the OSHA regulations still is based on the earlier versions they cite. A proposal for revision of the OSHA Subpart Q has been developed by the U. S. Department of Labor, but it must be published and subjected to public review and comment before it can be adopted. Until then, the current regulations will remain in force. CONCRETE CONSTRUCTION will alert readers when the publication date is known, so that they will have an early opportunity to comment on proposals for change that may affect their interests.

detailed requirements. The latest revision of Chapter 6, adopted with other code changes by the American Concrete Institute in 1983, permits use of nondestructive testing methods to determine whether concrete is strong enough for form removal. Howe ve r, this change in ACI 318 may not necessarily be applied in areas where earlier standards are being followed, and it is subject to approval by the local building official. Earlier ACI code versions called for field-cured cylinders as a basis for strength evaluation.

American National Standards Institute guidelines

The American National Standards Institute documents are in themselves voluntary consensus standards, not legally binding. Howe ve r, ANSI A10.9-1970, "Safety Requirements for Concrete Co n s t ru c t i o n and Masonry Wo rk ," assumed new significance when it was incorporated by reference into the OSHA regulations for concrete work. The 1970 version is still the core of OSHA's regulations, but ANSI has since issued new recommendations in line with current practice and information, in A10.9-1983, "Concrete and Masonry Wo rk -- Safety Requirements." This revised standard has been developed as a guide for contractors, labor, and equipment manufacturers; it will likely be referenced for this purpose in any new OSHA regulations.

committee, drawn from many areas of the concrete industry, devoted to setting standards for both quality and safety of formwork. The current standard, ACI 347-78, "Recommended Practice for Co n c re t e Fo rm w o rk ," is not a legal document. Rather it is a guide to good state-ofthe-art practices in forming. It presents 36 pages of basic recommendations for form design and construction, including loads and p re s s u re s, safety factors, and shoring and reshoring procedures. Fo rm w o rk for Concrete develops the principles of ACI 347 in a comprehensive how-to-do-it volume of 464 pages, abundantly illustrated.

Code compliance only the first step

By their nature, codes set minimum standards in the effort to protect workers and the public, but they can give no absolute guarantee of safety. There are too many other workplace practices and conditions that affect the balance between safe and unsafe conditions. Howe ve r, once a failure has occurred investigators are sure to zero in on what code provisions were violated. So, it's wise to keep in touch with changing requirements in codes and standards, recognizing that they are always necessary but not always sufficient for safety.

State and local codes

Some state and local codes, for example that of the City of New York, have their own highly specific provisions for form and shore removal and other aspects of formwork safety. Each builder must of course be familiar with the codes peculiar to his own area. Howe ve r, many local building codes are patterned after one of the so-called model codes such as BOCA, UBC or the Southern Standard Building Code. Treatment of concrete construction in these codes is frequently minimal, again incorporating some other document by reference. ACI 318, "Building Code Requirements for Reinforced Co n c re t e," is often the one included. Chapter 6 of ACI 318 deals with formwork, embedded pipes, and construction joints. Provisions covering formwork are brief, generally performance oriented, with few specific

ACI formwork recommendations

Since 1955, the American Concrete Institute has had a technical

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