THE EFFECTS OF CARBONATION ON BLENDED CEMENT CONCRETES

Alhassan A. Yunusa

Department of Civil Engineering,

Federal Polytechnic Idah, Kogi State

E-mail: alhassanay@gmail.com

Abstract: This paper reports on the results of a study undertaken to assess the carbonation of blended concretes exposed to a range of micro-climate variations in inland environments, particularly with variations in carbon dioxide content, temperature and relative humidity conditions. Concretes samples were prepared using five binder types representing variations of blends with GGBS, FA and CSF and four w/b ratios ranging from 0.4 to 0.75 and subjected to different degrees of initial water curing. These samples were placed in three exposure conditions: indoors in laboratory air, outdoors sheltered from rain and sun and outdoors fully exposed to the elements. The depths of carbonation of these samples were monitored over a period of 24 months in order to determine the rates of carbonation. Findings suggest that the rate of concrete carbonation may be usefully applied as performance specifications where durability of reinforced concrete structures must be guaranteed.

Keywords:    Durability, Supplementary cementing materials (SCM), Blended Concretes, Reinforced concrete structures.