THE CONCRETE BRIDGE MAGAZINE

SPRING 2017

ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.

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ASPIRE Spring 2017 | 51 should factor into the space-identification process. Signage that identifies potentially confined spaces is a great way to protect crews from unknowingly entering a confined space. The nature of construction means that possible confined spaces are constantly changing. In segmental concrete bridge constr uction, the inside of a form traveler is a constantly changing environment, where short sections of a bridge are constructed with many different trades occupying the same space at overlapping intervals, each introducing a different set of hazards. A confined space may not be present at the start of a segment cycle, but if thermal blankets are used to enclose the space for heating, and the same space is then occupied by a gas-powered concrete vibrator, the environment needs to be reevaluated to confirm that it is safe for all workers present. If the exhaust is found to be creating a hazard, one solution would be switching to electric vibrators using external power sources. The inside of a bridge, where crews may be applying an elastomeric coating to post-tensioning anchors, is a likely example of a permit space, given the enclosed environment and any health hazards associated with the product. Specific conditions will warrant varying controls, but entry and exit points to the areas where hazardous work is occurring should be clearly marked. Those involved should be well trained on the hazards. Those occupying the same confined space must also understand how the environment has changed so they can take the proper precautionary measures. Whether the confined space is c o n s i d e re d a p e r m i t - re q u i re d o r nonpermit space, emergency rescue procedures must be built into the construction plan, as it may be difficult to extract an injured person from the space. An emergency response plan should be developed and reviewed with local fire departments for the most efficient and safest way to rescue an injured employee. Considerations to discuss include access to the employee, such as high- angle rescue, or rescue from a snooper truck, truck ladder, aerial lift, or crane and rescue basket; atmospheric hazards, such as oxygen, carbon monoxide, hydrogen sulfide, or lower explosive or lower flammable limits, and any exposure above the permissible exposure level; and physical hazards, such as lighting, slips, trips, falls, and electric shock. Prior to workers entering a confined space, the lead contractor must coordinate and communicate emergency response procedures, OSHA requirements, and the responsibilities of the confined space supervisor, attendant, and entrants with all employees, subcontractors, and owners. Summary There is an OSHA standard for construction work in confined spaces that has different requirements from the one for general industry. It is vital that the construction industry be proactive and institute a thorough program to keep employees safe and to mitigate the hazards due to confined spaces. _______ John Kinkle is a project manager with PCL Civil Constructors Inc. in Raleigh, N.C. Enclosed outer cells were identified as confined spaces, separately from other interior sections of the bridge segments. Photo: Kenneth Payne. Introduction of a gas-powered concrete vibrator requires a review of the space to determine if it is a confined space. Photo: John Kinkle. EDITOR'S NOTE The information required by the n e w s t a n d a r d i s t a k e n f r o m t h e O S H A w e b p a g e " C o n f i n e d S p a c e s in Construction – Frequently Asked Questions" found at https://www.osha .gov/confinedspaces/faq.html. Signs help identify confined spaces to workers or inspectors not directly involved with an operation. Photo: Andrew Mahoney.

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