No abstract

Chloride apparent diffusion coefficient (Dapp) of a porous media is an indicative of its capacity to resist chloride ingress. It is used to predict the service life of reinforced concrete structures. This paper presents experimental study to measure the effect of blended cement paste containing Sudanese Natural Pozzolana (SNP) from Bayuda Desert in the Northern State on Dapp by using Bulk Diffusion Test (Nord–Test NT–Build 443). Three mixes are investigated, each mix contains 3 specimens, the first mix is a reference mix with 100% Ordinary Portland Cement (OPC) compared with second mix having another containing 75%OPC:25%NP, third mix having 50%OPC:50%GGBS. All pastes have water binder ratio of 0.55. The Dapp of 50%OPC:50%GGBS is found to be 1.794*10-6 mm2/s which is lowest among the pastes. The Dapp for 75%OPC:25%NP is 2.80*10-6 mm2/s and the Dapp for 100%OPC is 3.145 *10-6 mm2/s which is the highest.