Standards of Steel Construction - Dissertation Example

 Standards of Steel Construction Introduction Standards govern almost a 100% of the goods and services that mankind produces. The set standards ensure that products work properly, interactively and responsibly from the initial design to its final operational state. Generally, standards have and will continue playing a vital role in all aspects of our economy especially in the technology and science fields. An economy without production standards of goods and services is just like a country without a government or administration structure of government. The steel industry plays a major role in steering the economy of United States of America. The American government has been vocal in setting of standards of the various sectors of the economy and has always set the pace in most of the industries. The standards are highly intended to ensure that a particular set of guidelines are followed and the products production meets a particular grade. The international standards are geared towards customer satisfaction emphasis, more process emphasis, monitoring of the measurable objectives and is more quality oriented (Government of Canada, 20). Standards also ensure that products meet universal standards for compatibility reasons. The major problem or obstacles faced in the standardization industry is the rate of change in technology therefore demanding more robust and commonly accepted standards. The ability of the United States of America standards developers to effectively meet these needs is crucial to the success and future of not only the steel industry but also the rest of the sectors of the economy. Just like in any other industry, there has been development of trade practices among those who are directly and indirectly involved in the design, purchase, fabrication and erection of structural steel. The development of the steel code of practice and the standards is a vital move useful to owners, architects, engineers, general contractors, fabricators, construction managers, steel detailers and erectors associated with construction in structural steel. The two documents provide the standard custom and usage of the industry and are thereby incorporate into the relationships between the parties to a contract. Early Attempts at Steel Industry Standardization The steel industry is known to be a very dynamic field in terms of the country leading in production as well as the range of products. Analysis of the steel industry indicates that from the period starting 1910 till the year 1960, the first position in terms of production of steel in the world was held by the USA. In the recent times, India and Brazil have shown improved performance in terms of steel production but china is the biggest producer as at the moment. The steel industry has embraced merger and acquisition practices as well as downsizing. The industry is moving from the traditional labor intensive one to a capital intensive industry. In the recent times, the industry has registered high rate of growth with the main factor being the excess demand for steel generated by the construction, automobile and infrastructure industries (ASTM, Due to the dynamic nature of the steel industry, there required to be a regulatory body to check on the quality standards of steel products availed to the consumers. There was need for a body to ensure that the end consumers of steel products are not exploited by the major industry players. Also there was need to standardize the products for compatibility purposes of the products from the different market players. It would not be satisfactory to the consumer to buy all the steel products from one of the major industries due to compatibility limitations (Blanc, McEvoy & Plank, 391). Also there was need for the industry players to be forced to improve the quality of steel especially that which was mined and determined to be of poor quality like the Chinese steel. The US government in the early development of the steel industry sort to standardize steel industry from the traditional contract specific requirements to commonly accepted commercial practices with the goal of standardizing the means of drafting and fulfilling contracts. This was aimed at achieving better consistency through the already convoluted supply chain. The USA government first met with other world’s leading steel contractors and came to an agreement that an internationally accepted standard should be put in place throughout the industry. Their attention was drifted towards the already established ISO 9000 quality standards as the de facto benchmark to follow (Bangash, 98). The international organization for standardization (ISO) 9000 focused on both management and assurance as a means of effective documentation, maintenance and tracking of an efficient quality standard. The standard was too general to serve the steel industry fully therefore the need for a more specific one well suited for the steel industry. The first attempt to standardize the industry was done in the early 1920’s with the first edition of the code being published in 1924. The American Institute of Steel Production was established in 1921 to serve the need for steel application in construction and other fields. The aim of the American Institute of Steel Production was to become the first choice in steel relate areas including the norms and codes, research, education, technical support, standardization, quality certification and market development. The code has been periodically updated to reflect the new and changing technology as well as industry practices. By 1927, thirteen editions had been released and the code has undergone lots of revisions and improvements to accommodate fully all aspects of the ever dynamic steel industry. The 2000 edition was the 2005 edition which was the fifth complete revision of the code since its publishing. Though it is not a complete edition it addresses most of the steel industry issues and adds several important changes and updates. To ensure that the document was all inclusive, the membership of the review committee included six structural engineers, two architects, one code official, one general contractor, eight fabricators, one steel detailer, three erectors, two inspectors and one attorney. For many years now, the United States of America has been the leader in standardization not excluding the steel standardization (Porter, 100). In the recent years, the USA industry experienced a shift in standards control from the central government to commercial bodies. Although the move’s intention was to strengthen the industry, it has highly weakened the steel industry infrastructure through decentralization. In order to alleviate this problem, the standards bodies need to work closely together for the steel industry integration and promotion of healthy business practices. By unifying the steel standards at the national level the United States of America will be better equipped to successfully compete in the steel markets all over the world. Obstacles Facing Standardization The greatest obstacle facing standardization bodies is the dynamicity of the steel industry. The steel industry has been very dynamic in its operation as well as technologically. Spurred by a number of new ventures and steel mines discovery all over the world, the steel industry is expanding fast (Bjorhovde, 57). As mentioned earlier different mines have different quality of steel and therefore to sustain the new rapid growth there is need to for the creation of more robust and commonly accepted standards. The inability of the United States of America standards developers to effectively meet the needs of the industry will lead to failure and blurred future of the entire steel industry. General Provisions in Undertaking a Steel Construction Work The code of standard practice for steel buildings and bridges trade practices govern the fabrication and erection of structural steel. The code defines the commonly accepted standards of custom and usage for structural steel fabrication and erection. The code defines not the professional standard of care for the design, change of duties and responsibilities of the contractor, owner, structural engineer or the engineer from those set in the contract documents (Attia & Waterhouse, 182). The code does not assign to the owners, structural engineer, engineer or whoever is privy to the contractual agreements any duty or authority to undertake responsibility inconsistent with the contract documents provisions. In undertaking the steel construction job, one has to put into consideration the design criteria, design responsibility, patents and copyrights, the existing structures, and the means, methods and safety of erection. The design criterion of the structural steel of buildings is governed by other design criteria other than the AISC specification. In the absence of any other design criteria the AISC guidelines are applied. The code plays no role when the owner has provided the designated representative for design that stipulates the design, specifications and the design drawings. In such a case the fabricator and the erector are not held responsible for the suitability, adequacy or building code conformance of the design (Berger & Mordfin, 111). The fabricator is held responsible for the suitability, adequacy, conformance with owner established performance criteria and building code conformance of the structural steel design if the owner directly contracts with the fabricator to design and fabricate the entire, completed steel structure. Any design that the fabricator or the owner comes up with legally belongs to the creator and thus should not be used other than with the permission of the creator. The creator holds exclusive rights to the use and copyright of the design. Any use of the design should conform to the intellectual rights provisions. In terms of the existing structures, the fabricators and erectors holds no responsibilities in demolition and shoring of any part of the existing structure or the protection of the existing structure and its contents and equipment. The demolition, shoring, surveying or field dimensioning, abatement or removal of hazardous materials or protection of part, contents and equipment of an existing structure should be done in a timely manner so as not to inconvenience the fabricator or the erector in his work. It is the erectors responsibility to ensure the best means, methods and safety of erection of the structural steel frame. The structural engineer is responsible for the structural adequacy of the completed project structure design and is not held responsible for the means, methods and safety of erection. The contractors and sub contractors should be provided with information regarding the project planning and erection sequence by the designer o r the principal contractor. Before the commencement of the work, the principal contractor should receive a program that includes a comprehensive erection method utilizing the risk management procedures from the erector. The program should lay emphasis on safety and healthy management clearly setting out solutions to curb identified risks (American Bridge Company, 57). The whole erection method highly depends on the size and complexity of the work and the risk assessment results, and should constantly be reviewed to suit the current situations. In order to ensure the right structure is erected, there are the general procedures to follow namely; safe work methods should be put in place; the erector should possess the right and relevant qualifications and experience or a competent person should supervise the work; when working on a building, a rigger should always wear the safety harness supplied by the employer; before a rigger works or moves about steel work, there should be secure anchorage for lanyards, arresting devices and static lines termination put in place; there should be ladders to be used by the riggers when connecting beams or columns unless anchorage for a safety harness has been provided for the rigger to be secured and then work from the ladder; the working decks should be fully decked out to protect the employees working at lower levels from the falling objects; and a rigger should not be allowed to work on a building where he can fall without another person in attendance or close vicinity. There should be post fall recovery plans to avoid long periods of post fall suspension of riggers. Classification of Materials The classification of materials may fall under the following categories; structural steel; and other steel, iron or metal items. In building and construction field, structural steel is mostly used. Steel is an alloy consisting mostly of iron with 0.2% to 2.1% by carbon weight. Carbon and other elements are hardening agents of steel preventing dislocations in the iron atom crystal lattice sliding past each other. The qualities of steel such as hardness, ductility and tensile strength are controlled by varying the amounts of alloying elements and form. High carbon content hardens steel but makes it less ductile. Structural steel is a construction material made of steel that is formed in a specific shape or cross section and certain chemical composition and mechanical properties standards. Regulation of the various properties of structural steel like shape, size, composition, strength and storage is common in most of the industrialized countries. According to generally accepted standards, structural steel consists of the structural frame shown and sized in the structural design drawings that is essential to support the design loads. This includes the anchor rods, base plates, beams, bearing plates, bearings of steel for girders, trusses or bridges, bracing, canopy framing if made from standard structural shapes, columns if made from standard structural shapes and/plates, connection material for framing the structural steel to structural steel, crane stops, door frames, edge angles and plates, embedded structural steel parts and fasteners for connecting structural steel items among others. For an item to be referred to as structural steel, it must be shown, sized and described in the structural design drawings. Vertical bracing for wind resistance and seismic load and structural stability, the horizontal bracing for the floor and roof systems and the permanent stability bracing for components of the structural steel frame are part of the bracing. Other steel, iron or metal items are the other items that may be furnished by the fabricator as per the specific notation and detail in the documents of contract. This may include; bearings if not steel, cables for permanent bracing or supervision systems, castings, catwalks, chutes, cold formed steel products, cold rolled steel products, corner guards, forgings, gage metal products, grating, floor plates if not attached to the structural steel frame and flagpole support steel among others. Specifications of the Designs The structural design drawings should be based upon design loads consideration and forces that are to be resisted by the structural steel frame in the completed project. The structural design drawings should clearly show the work to be performed and clearly show the size, section, material grade and location of all members, floor elevations, column centers and offsets, the chamber requirements for members, all geometry and working points necessary for layout, and the required information with sufficient dimensions to accurately convey the quantity and nature of the structural steel to be fabricated. The specification should any include all the special requirements for the fabrication and erection of the structural steel. It is always advisable to number and date the structural design drawings, specifications and addenda for identification purposes. The fabricator and the erector must be able to rely upon the accuracy and the completeness of the contract documents so as to provide the owner with bids that are adequate and complete. This also will enable the preparation of the erection and shop drawings, ordering of materials and fabrication and erection of shipping pieces that is timely. It would be to the benefit of the owner if reasonable latitude is allowed in the contract documents for alternatives that will allow for cost reduction without compromising on quality. The critical requirements prerequisite in protecting the owner’s interests, affecting the integrity of structure and necessary for the fabricator and the erector to proceed with their work should included in the contract document. Some of the critical information include; standard specifications and codes that govern structural steel design and construction up to and including bolting and welding; material specifications; special material requirements to be reported on the certified mill test reports; configuration off the welded joint; stability and lateral bracing; weld procedure qualification; column web doubler plates; and special erection limitations among others. The owner’s designated representative for design should show the complete design of the connections in the drawings of the structural design or allow the fabricator to select, complete the fabrication and connection details while preparing the shop and erection drawings (McCormac, 384). Any restrictions on the types of connections permitted, data concerning the loads, shears, moments axial and transfer forces to be resisted by the individual members and their connections that is sufficient to allow the fabricator to select or complete the connection details and whether this information is given at the service load level or the factored load level, and whether LRFD or ASD is to be used in the selection or completion of connection details information should be provided if the fabricator is allowed to complete and select the connection details. The owner should provide all the information in relation to the complete design of the connections in the structural design drawings. This information relates to the weld sizes and lengths, bolt sizes, locations, quantities and grades, plate and angle sizes, thicknesses and dimensions, and work point locations and the related information. This ensures that all the necessary information in relation to detailing, fabrication and erection is clearly shown in the structural design drawings. This will enable the detailer to clearly transfer this information to the shop and erection drawings. As the construction continues, design drawings and specifications revisions can be made through issuance of sketches and supplemental information separate from the design drawings and specifications. The sketches and supplemental information amend the design drawings and specifications and therefore considered new contract documents. They should be clearly and uniquely identified with a number and date as the latest instructions till they are superseded by new information. When there are revisions through revising and re-issuing the existing structural design drawings and/or specifications, a unique revision number and date should clearly identify the information as the latest instructions till the information is superseded by new information. For easy tracking of revisions there should be a unique number identifying each design drawing throughout the duration of the project. This will help in confusion avoidance and miscommunication among the various entities involved n the project. A written confirmation should always accompany revisions so as to maintain control of the cost and schedule of a project and to avoid potential fabrication errors. It is the responsibility of the owner to furnish in a timely manner and in accordance with the contract documents the complete structural design drawings and specifications released for the construction purposes. The released for construction design drawings and specifications is required by the fabricator before he can order materials, prepare and complete chop and erection drawings. Shop Drawings, Materials, and Fabrication Delivery The owner is held with the responsibility of furnishing in a timely manner adhering the terms in the contract documents the complete structural design specifications and drawings released for the construction work. The owner must issue released for construction so as to give the erector and the fabricator the go ahead in construction. This document is usually taken as the owner’s requirement for construction project. Revision of the document should not be so frequent so as to enhance and ensure consistency in material procurement, fabrication and erection jobs, detailing and phased construction. It is the responsibility of the fabricator to release shop and erection drawings for the structural steel fabrication and erection. He has the duty of transferring information accurately and completely from the contract documents to the shop and erection drawings. He is also responsible for the development of accurate and detailed dimensional information in provision for the fit up of parts in the field. Each and every shop and erection drawing should be uniquely identified with a unique number throughout the project duration as well as identified uniquely by a revision number and date whereby each revision is identified clearly. Any drawing or part of the design drawings of the shop and erection should not be reproduced without the prior permission from the owner. The fabricator should seek the approval of the owner whenever he carries out a revision. The owner shall give confirmation that the fabricator has interpreted the contracts documents correctly in the preparation of the documents to be submitted. However the owner’s approval shall not relieve the fabricator from the responsibility of accurate detailed dimensions in the shop and erection drawings or for the assembly parts. The fabricator is held with the responsibility of determination of the fabrication schedule necessary in the adherence of the terms in the contract documents. There are circumstances where the erection and shop drawings are not prepared by the fabricator but are furnished by others. In such circumstances, the drawings are to be timely delivered to the fabricator so as not to inconvenience the fabricator in his work. It is the responsibility of the fabricator to order the materials necessary for the fabrication as soon as he receives the contract documents released for construction purposes unless otherwise stated in the contracts documents. There are two types of materials: mill materials and stock materials. He may purchase the materials that suit the structural design drawings dimensions. This may be in stock lengths, exact lengths or multiples of exact lengths. Quality Assurance The quality assurance program will be maintained by the fabricator. This is so to make sure that the work is done in line with the requirement of this code, the Specification of the AISC and Contract Documents. There will be an option for the fabricator to use the Quality Certification Program of the AISC so as to establish and implement the quality assurance program. However, the program neither involves looking at the product quality of individual projects, nor gives a guarantee on quality of Structural Steel Products that are fabricated. The functions of the Erector include erection of the Structural Steel and provision of tools, human resource and management for the scope, size and quality required of each project. There will be an option of the Erector to use the Erector Certification Program of the AISC so as to put in place and check on the quality assurance program. If the owner needs a more extensive quality assurance or the fabricator to be certified in the AISC Quality Certification Program, it will necessitates to be clearly stated in the Contract Documents including a definition on the scope of that inspection. Because of the rapidly increasing use of exposed structural steel which is used as a medium for the architectural expressions, there is an increase on demand for dimensional tolerances and surfaces with smoother finishes. This will take in to account the desired finished appearance of the product and whether the fabrication shop will produce the desired product. This will be in accordance with the Architecturally Exposed Structural Steel (AESS). A table of different classes of steel and their properties is shown in appendix 1. Testing, certification and conformity assessment program for steel products Before any steel product can be used it has to be tested, certified and assessed for conformity with the code of practice in steel construction and code of standard practice for steel buildings and bridges by the American Institute of Steel Construction, Inc. Testing, certification and standards conformance should be taken into consideration by every person taking part in the construction work ranging from engineers to fabricators. The AISC is also responsible in ensuring that the steel products meet the standards to ensure the consumers safety. Also the government has enacted the steel products Procurement Act that will guide engineers, contractors and fabricators in their work. It is the obligation of the engineer to ensure that the steel production has been carried out in safe environments and the products meet the requirements. There are also independent bodies that carry out certification of the steel products like Association Francaise de Certification des Armaturs du Beton(AFCAB). These independent bodies ensure the steel products meet current standards, checked at each stage of manufacturing and keep their properties after been bent or straightened. AFCAB implements a quality system based on NF EN ISO 9001 standards. The owner may also appoint independent inspectors other than the independent bodies or government agencies to inspect the fabricators work for conformance to the standards stipulated in the contracts documents. Works Cited American Bridge Company. Structural steel: properties of structural shapes and structural members with tables giving allowable load for columns, footings, beams and angles, California. American Bridge Company. 2007. ASTM, The economic benefits of standardization, ASTM business link. retrieved on 7th july 2010 from http://www.astm.org/buslink/buslinkA01/din.html, 2001. Attia M. H., Waterhouse R. B., Standardization of fretting fatigue test methods and equipment (illustrated), ASTM International, 1992. Bangash M. Y. H., Structural detailing in steel: a comparative study of British, European and American codes and practices, Thomas Telford, 2000. Berger H., Mordfin L., Nondestructive testing standards--present and future(illustrated), New York, ASTM International, 1992. Blanc A., McEvoy M., Plank R., Architecture and construction in steel(illustrated), London, Taylor & Francis, 1993. Bjorhovde R., Structural steel selection considerations: a guide for students, educators, designers, and builders(illustrated), New York, ASCE Publications, 2001. Government of Canada, The importance of standardization Retrieved on 9th July 2010 from www.energyrating.gov.au/pubs/2004ac2plen-miller.pdf McCormac J. C., Structural steel design(4th edition, illustrated), London, Prentice Hall, 2008. Porter T., Technology, governance and political conflict in international industries(illustrated), london, Routledge, 2002. Properties Carbon Steels Alloy Steels Stainless Steels Tool Steels Density (1000 kg/m3) 7.85 7.85 7.75-8.1 7.72-8.0 Elastic Modulus (GPa) 190-210 190-210 190-210 190-210 Poisson's Ratio 0.27-0.3 0.27-0.3 0.27-0.3 0.27-0.3 Thermal Expansion (10-6/K) 11-16.6 9.0-15 9.0-20.7 9.4-15.1 Melting Point (°C)     1371-1454   Thermal Conductivity (W/m-K) 24.3-65.2 26-48.6 11.2-36.7 19.9-48.3 Specific Heat (J/kg-K) 450-2081 452-1499 420-500   Electrical Resistivity (10-9-m) 130-1250 210-1251 75.7-1020   Tensile Strength (MPa) 276-1882 758-1882 515-827 640-2000 Yield Strength (MPa) 186-758 366-1793 207-552 380-440 Percent Elongation (%) 10-32 4-31 12-40 5-25 Hardness (Brinell 3000kg) 86-388 149-627 137-595 210-620 Appendix 1 Steel Properties Read More