Bridge Deck Surface Preparation Using High Pressure Water
This section includes the provision for all labor, materials, equipment and supervision necessary to clean existing concrete surface as indicated on the drawings and in the specifications, including but not limited to:
- Cleaning concrete surfaces using ultra-high pressure (36,000 psi) water.
- Cleaning all cracks in the concrete surface using high-pressure water.
- Wet vacuuming of the surface immediately after rinsing.
The method of cleaning shall be limited to ultra-high pressure water blasting. No other method will be allowed. The purpose of this procedure is to thoroughly clean the surface and all cracks such that a surface treatment, when applied to the deck, will penetrate and fill the cracks. Ultra-high pressure water as described herein is the only method that will thoroughly flush the cracks removing contaminates that will interfere with the penetration of the surface treatment.
- Submit a list of at least four similar projects performed within the past four years. Include the name of the project, location, area cleaned, size of the area, material applied, name of the owner of the structure and the name and phone number of the individual responsible for overseeing the work performed.
- Submit manufacturer’s specification for high pressure cleaning equipment including operating procedures and parameters. Include the operating pressures, water flow rate and production capabilities when used for similar applications.
- Submit the manufacturer’s specification for the wet vacuum system.
- Submit proof that the operator of the high pressure cleaning equipment has been trained and certified in the correct use of the equipment by the manufacturer and that they have at least two years experience operating the equipment.
- Submit verification that the supervisor of the work described in this specification has performed similar work on at least two projects. Submit a list of at least two similar projects performed within the past two years. Include the name of the project, location, area cleaned, size of the area, material applied, name of the owner of the structure and the name and phone number of the individual responsible for overseeing the work performed.
- Work shall be performed by organizations that have successfully performed at least four verifiable projects similar to this project within the last four years.
- Work shall be under the immediate control of a person experienced in this type of work. The person identified with immediate control of the work shall have supervised two verifiable projects of similar magnitude and type within the past two years. Supervising person shall be present during all operations.
- The high-pressure water cleaning system shall be operated by an individual trained and certified by the equipment manufacturer and having a minimum of two years experience.
- The supervisor shall meet daily with the owner’s authorized engineer and examine the work performed during the previous shift. The work shall be either approved or if the cleaning is not satisfactory the area shall be re-cleaned immediately.
High Pressure Water Cleaning Equipment
- Cleaning shall be performed with engineer approved high-pressure water equipment. The equipment shall be capable of maintaining 36,000-psi water pressure at a minimum flow rate of 16 gpm. The equipment shall be capable of cleaning a minimum of 10,000 square feet per hour under normal operation. It shall be mobile and contain a minimum 4,000-gallon water tank thus allowing for continuous operation. The cleaning head shall contain a minimum of 28 nozzles. The cleaning head shall be capable of rotating at a minimum of 1,500 rpm to ensure uniform cleaning. The equipment shall be capable of cleaning within three inches of vertical surfaces such as curbs and barriers.
- The equipment shall be capable of cleaning the deck surface and all cracks to thoroughly remove all dust, dirt, oil, wax, curing compounds, efflorescence, laitance and other foreign materials without causing damage to the surface by etching or exposing coarse aggregate.
- The wet vacuum system shall be capable of vacuuming the surface and removing all water and debris at the rate of 10,000 so/hr.
- All equipment shall be safe and meet applicable OSHA requirements.
Testing and Acceptance of the High Pressure Cleaning Equipment
A trial area will be designated by the engineer to demonstrate that equipment, personnel and methods of operation are capable of producing results satisfactory to the engineer. The trial area shall be at least 100 feet long by 10 feet wide.
The equipment shall be calibrated to at least 36,000 psi and 16 gpm. The equipment shall start cleaning at one end of the test area and travel to the other end (100 linear feet). All procedures shall be demonstrated including the wet vacuum. The production rate of each piece of equipment and the combined operation, as measured in square feet per hour will be determined.
The surface shall be examined to determine if all contaminates have been removed and that the surface has not been damaged. Cracks will be examined to determine if contaminates have been flushed and removed.
If in the sole opinion of the engineer the high pressure cleaning equipment does not produce satisfactory results or if the equipment cannot maintain the specified pressure and flow rates or production rates during the test, then the engineer will require that the equipment be removed from the project and replaced with equipment that can meet the requirements of the specifications. No additional time will be allowed for failure to bring the proper equipment to the project. Any substitute equipment must first be tested as described herein prior to acceptance for the project.
Water for use during cleaning operation and cleanup process shall be furnished by the owner at no cost to the contractor. Water will be supplied from a hydrant located at _________________________. The owner will obtain a permit for use of the hydrant.
The contractor is responsible for supplying all equipment and tools necessary to tap into the water source.
Water vacuumed up during the cleaning process will be discharged into the storm drains located on or adjacent to the bridge. It is recognized that the water from the cleaning operation contains dust, dirt, debris and other materials that are normally located on the bridge deck and that are flushed down the storm drains during periods of rain. As a result the cleaning operation and discharge of water does not represent a threat to the environment.
Operation of the high pressure cleaning equipment shall be performed and supervised by qualified personnel certified by the equipment manufacturer.
All water used for cleaning shall be potable.
Contractor shall provide adequate lighting as required to perform cleaning.
Contractor shall maintain, on the job site, an inventory of common wear parts and replacement accessories for equipment adequate to ensure that routine maintenance tasks can be performed quickly without delay to the project.
Any prepared areas contaminated as a result of the contractors operations shall be re-cleaned at no additional cost to the owner.
Inspection of the Cleaned Area
After each cleaning shift the engineer will examine the cleaned surface to verify that the surface is clean and free of contaminates and that the cracks are clean and free of contaminates. Where unsatisfactory cleaning has been performed, the engineer will direct contractor to perform additional cleaning. Engineer will re-inspect after each additional cleaning.
After inspections are complete and all cleaning accepted, the engineer and contractor shall measure and document the approved areas for payment.