Page 8-84 M 41-10
8-17 Impact Attenuator Systems8-17 Impact Attenuator Systems
8-17.1 Description
This Work consists of furnishing, constructing, repairing, and removing permanent and temporary impact attenuator systems selected from the approved list shown in the Plans.
8-17.2 Materials
Materials for inertial sand barrel systems shall be provided and installed in conformance with the manufacturer’s instructions and specifications. Undamaged sand barrel impact attenuators that have been previously utilized may be utilized in a temporary impact attenuator array only, if inspected and approved by the Engineer prior to use.
8-17.3 Construction Requirements
The assembly and installation of all attenuator systems, except those utilizing sand barrels, shall be supervised at all times by either a manufacturer’s representative or an installer who has been certified by the manufacturer of the system. If the supervision is provided by a certified installer, the certification shall be within the previous 5 years and for the specific system(s) being installed. A copy of the installer certification shall be provided to the Engineer prior to installation. Attenuator assembly and installation shall be in accordance with the manufacturer’s recommendations. This Work shall include the connection to a concrete barrier, bridge abutment or a transition section identified in the Plans. Construction of a concrete foundation or concrete backstop shall be as specified by the manufacturer. Anchorage to the pavement will follow the manufacturer’s assembly and installation procedures. Unless otherwise specified by the manufacturer, concrete foundations and backstops:
1.Shall be made of Class 4000 concrete meeting the requirements of Section 6-02.
2.Shall be cured and finished in accordance with Section 6-02.3(11). Attenuators shall not be installed on concrete foundations and/or attached to concrete backstops until the concrete has cured for at least 72 hours. The manufacturer’s representative or certified installer shall complete a manufacturer’s attenuator assembly/inspection checklist for each attenuator installed. The original completed checklist, signed by the manufacturer’s representative or certified installer, shall be provided to the Engineer on the same day that the attenuator installation is completed. The Contractor shall have a complete set of replacement parts on the jobsite for each type of temporary impact attenuator in use on the project and shall repair all damaged impact attenuators immediately. When the Engineer determines that a temporary impact attenuator is no longer needed, then the Contractor shall remove that attenuator from the project. The removed equipment shall remain the property of the Contractor. Permanent impact attenuators shall meet the crash test and evaluation criteria of the Manual for Assessing Safety Hardware (MASH), except as otherwise noted in the Plans or Special Provisions. Temporary impact attenuators shall meet the crash test and evaluation criteria of MASH or the National Cooperative Highway Research Project Report 350 (NCHRP 350) as specified in Section 1-10.2(3) . M 41-10 Page 8-85
8-17 Impact Attenuator Systems8-17.4 Measurement
Temporary and permanent impact attenuators will be measured per each for each installation. Only the maximum number of temporary impact attenuators installed at any one time within the project limits will be measured for payment. Resetting impact attenuators will be measured per each for each installation that is adjusted or reset to a new location on the project. The Contracting Agency will not measure resetting impact attenuators when it is for the benefit of the Contractor’s operations.
8-17.5 Payment
Payment will be made for the following Bid items when they are included in the Proposal: “Temporary Impact Attenuator”, per each. The unit Contract price for “Temporary Impact Attenuator” shall be full pay for all Work associated with the installation, maintenance, and the final removal of the temporary impact attenuator. “Permanent Impact Attenuator”, per each. The unit Contract price for “Permanent Impact Attenuator” shall be full pay for all Work associated with furnishing, installing and all other costs involved with installing the impact attenuator in accordance with the manufacturer’s recommendations. “Resetting Impact Attenuator”, per each. The unit Contract price for “Resetting Impact Attenuator” shall be full pay for all Work associated with the removing, transporting, and resetting an impact attenuator. If an impact attenuator is damaged by a third party, repairs shall be made in accordance with Section 1-07.13(4) under the Bid item “Reimbursement For Third Party Damage”. No payment will be made for repair of impact attenuators damaged by the Contractor’s operations.
Source: Washington Standard Specifications for Road, Bridge, and Municipal Construction, 2024 Edition. Pages 834–835 of 1,151.