CHLORIDE DIFFUSION-COEFFICIENT OF CONCRETE IN THE ARABIAN GULF ENVIRONMENT

This investigation evaluates the chloride diffusion coefficient for co ncrete made with marginal limestone aggregates and Type V Portland cem ent commonly used in the Arabian Gulf. Parameters investigated are (1) water-cement ratio, (2) cement content, (3) surface chloride concentr ation, and (4) exposure condition. An attempt is made to arrive at a m odel for predicting the onset of corrosion using the limited test data . The experimental results revealed that the chloride diffusion coeffi cient is strongly influenced by water-cement ratio and exposure condit ions and marginally by cement content but unaffected by the surface ch loride concentration. The chloride diffusion coefficient values ranged from (8 to 170) x 10(-8) cm(2)/sec for different concrete mixes and e xposure conditions. The high value of the chloride diffusion coefficie nt is mainly attributed to the low concrete quality and the local aggr essive environmental conditions. The basis of the prediction model to corrosion initiation has been set and reasonable results are produced based on the limited experimental data.