Characteristics of Reinforcing Steel
See FHWA’s CRCP Design and Construction Guidelines for the references included in this page. A new, more comprehensive FHWA CRCP Design, Construction, Maintenance and Rehabilitation manual is currently under development and this page will be updated upon its release in the spring of 2016.
Only deformed steel bars should be used as reinforcement for CRCP. Reinforcing steel bars are characterized by size and yield strength (or grade). Standard ASTM reinforc- ing bars are required to be marked distinctively for size and minimum yield strength or grade. The figure to the right shows an example of the ASTM marking requirements for a #8, Grade 60 (#25, Grade 420 metric) bar. ASTM specifications require the bar size number (e.g., #8) to be rolled onto the surface of the bar as shown in the figure.
These specifications also allow a mill to choose to roll the grade number onto the bar, or roll on a single longitudinal rib or grade line to indicate Grade 60. Additional informa- tion about steel bar marking and identification is available in ASTM A615/A615M-96a, ASTM A706/A706M-96b, and ASTM A6/A6M-96.(76) The identification marks on bars delivered to the job site should be checked regularly against those shown on the plans. Certified Mill Tests and/or Bar Coating Reports should accompany shipments of reinforcing steel to the job site as shown in the figure to the right.
A light brown coating of rust on reinforcing bars is considered acceptable by industry. Although cited ASTM standard specifications do not consider the presence of mill scale as cause for rejection, a recent ACI paper found that bars with mill scale produced more corrosion compared to other bars investigated.(110)
Reinforcing steel should be stored on platforms off the soil to prevent damage and deterioration.