INITIAL BINDING CAPACTIES OF CHLORIDE ION OF COMPONENTS IN HIGH-PERFORMANCE CONCRETE

An investigation is reported on the influence of different components of high performance concrete (HPC) on the initial binding capacities (IBC) of chloride ion. The testing results demonstrate that cement has the largest IBC, and the relative binding ratio is as high as 30% of total ion amount. Among the mineral admixtures, fly ash has the largest IBC of chloride ion. The IBC of silica fume is about 14.4% ,which is smaller than that of fly ash. The IBC of refined ground blast-furnace slag (microslag) is abnormal due to the influence of sulfate ion contained. The addition of superplasticizer and corrosion inhibitor containing calcium nitrite weakens the IBC of mixtures. The fluidity and pore-filling effect of mineral admixtures are studied with paste samples with W/C ratio of 0.3. The influence mechanism of various components in high-performance concrete in IBC is studied further through SEM and Mercury Instrusion Porosimetry tests with paste samples at the age of 3 days.