In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Learn More
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute 38800 Country Club Dr. Farmington Hills, MI 48331-3439 USA
Phone: 1.248.848.3700 Fax: 1.248.848.3701 Staff Directory
Email Support
Feedback via Email Phone: 1.248.848.3800
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Cathodic Protection Criteria for Two-Layered Reinforced Concrete Sections
Author(s): Mohammad G. Ali, A. S. Al-Gahtani and R. Sri Ravindrarajah
Publication: Special Publication
Volume: 170
Issue:
Appears on pages(s): 1097-1118
Keywords: Cathodic protection; corrosion; reinforcement of concrete.
Date: 7/1/1997
Abstract:The results on the relatively high level of protection provided to the top steel in a reinforced concrete slab when the bottom steel is just adequately protected are presented in this paper. The steel reinforcement corrosion was accelerated with the use of chloride contaminated concrete. The chloride gradient within the specimen was created by inserting a relatively higher chloride bearing macrocell. Current reversal technique was used to monitor the corrosion protection level. The results showed that the presence of a higher chloride gradient requires a higher protection current density and potential. An instant-off potential of 632 mV CSE and a 4-hour decay potential of 100 mV were sufficient to protect steel reinforcement against corrosion in chloride rich concrete (19 kg/m3). The protection level at the top steel is significantly high when the bottom steel is just adequately protected from the anode source located above the top steel. In a chloride bearing concrete with the chloride gradients of 3.0 and 1.5, the top steel received 103 and 59 mA/m2 cathodic protection current densities compared to the current densities of 42 and 31 mA/m2, respectively required to protect the bottom steel. The instant-off potential of 730 mV CSE and the decay potential of 128 mV for the top steel also indicate a relatively high level of protection of the top steel. In a two-layer steel reinforced concrete slabs, it is necessary to develop a mechanism, specially in new construction, to facilitate the flow of current to the bottom steel. The current reversal technique used in the test was effective in determining the protection level against corrosion.
Click here to become an online Journal subscriber