Basic Safety
Hand-held radio, red lanterns or WMATA Approved E-flares, Work mats, Wayside Strobe and Audible Device
What is Required Safety Equipment?
Sounding with a hammer, sounding with a chain drag, Ultrasonic testing
What are methods of locating concrete damage?
Section loss, Damage during concrete removal, Lack of bonding surface for patch material
What is why should steel be replaced?
Very critical to the success of the steel replacement repair.
What is a bond or bonding?
Selection of delivery method, no segregation through application methods of mixing, complete filling of voids.
What is consideration of delivery methods?
Approved safety vest or shirt, Safety Glasses, Hard Hat, Safety Shoes, Flashlight
What is Personal Protective Equipment (PPE)?
Flaking, Soft, Porous or poorly consolidated concrete
What are concrete conditions that require removal?
When more than 25% of cross section has been lost to corrosion. When two or more adjacent bars have 20 percent of section loss.
What is when to replace corroded steel?
Cement base slurries, Latex modified slurries, Latex agents, Epoxy.
What are types of bonding agents?
A satisfactory bond, fill the cavity without segregation (separation), fully encapsulate the rebar.
What is what a delivery method must accomplish?
Must be worn when working with Hot Stick Testers, Shunts, Voltage Awareness Devices , and Warning Strobe and Alarm Devices (WASAD's)
What are High Voltage Electrical Safety gloves?
Track and maintenance departments use these for grout pad installation.
What is a pneumatic scabbler?
Lap Method, Swedged, Weld, Threaded Coupler
What are types of steel replacement methods?
Differing rates of expansion and contraction-old to new, gravity i.e. overhead applications, impact in roadway applications, vibrations caused by PLNT systems, traffic and seismic actions.
What subjects a bond to stress?
Material is forced to bond by applying hand pressure with a trowel.
What is hand applied Application method?
Mechanism utilized by workers when unsafe conditions occur in the work location.
What is a Good Faith Challenge?
Concrete is removed to expose corrosion, concrete is removed to a minimum of 3/4" below corroded steel, area is saw cut at 90 degree angle to clean up edges.
What is the removal method for corroded rebar?
Zinc acts as a sacrificial metal and keeps the corrosion from the steel. Gives cathodic protection.
What is a steel protection method?
A satisfactory bond, Fill the cavity without segregation (separation), Fully encapsulate the rebar.
What must a delivery method accomplish?
Air blown material applied to surface creating the force for bonding i.e. shot crete.
What is a Pneumatically applied application method?
Needed when handling chemicals or potential flying objects.
What are ANZI 87 rated Safety Glasses.
An abrasive used with high pressure air. Need for an enclosed area and air supplied respirator hoods.
What is Abrasive Blasting? (Sand Blasting)
Heavy oxidation-rust must be removed. Bars damaged while chipping or having significant section loss must be replaced. Cleaned or replaced bar must be coated with a sacrificial coating, i.e.
What are general procedure for the cleaning and replacement of steel.
Removal of old material. Clean the surface and rebar. Application of new material.
What are general procedures for bonding?
Form material is erected. Material is applied to an opening in the form, then vibrated to apply pressure.
What is form and cast in place method?