Chloride Penetration Depth in Silica Fume Concrete

Abstract

Abstract-This study was performed to evaluate chloride ion penetration depths in concrete produced with high early strength Portland cement with and without silica fume replacement (10% by mass). Two curing procedures were used to produce precast structures curing: air and steam curing at 60 ºC. Chloride ion depths were measured at 90 days by spraying a solution of 0.1N AgNO3 at specimen surfaces. The results showed that Chloride ion penetration depth in silica fume concrete was diminished.

Thermal damage and its controlling methods of high‐speed railway steam‐cured concrete: A review

“…Many research 15–17,52–59 showed that the pozzolanic effect, the micro aggregate effect, the interface effect, and the “superimposed compound effect” of TCM could effectively restrain the expansion deformation, refine the pore structure, and finally improve the microstructure of the concrete. The improving effect of using single TCM were as follows: (a) researchers 47,52,60–63 found that 20 ~ 30% FA obviously reduced the proportion of harmful holes (lager than 50 nm), enhanced the corrosion resistance, and also raised the later strength; (b) Seo et al 64 reported that 20 ~ 30% GGBS made the compressive strength exceed the design value of 28 days within 1 week and enhanced the freeze–thaw resistance of the internal structure; (c) Shen et al 53 and Zhang et al 54 pointed out that a few MK or LP could significantly raise the volume stability of the steam‐cured concrete; (d) studies 65–67 showed that the compressive strength, the reduction of the water absorption, and the resistance of the chloride ion permeability were enhanced by adding little SF or MK. The improving effect of using TCMs were as follows: (a) many researches 55,58,68–71 implied that when 30% cement was replaced by both FA and GGBS, not only the properties of the concrete surface layer were hugely enhanced, but also promoted the secondary hydration to further raise the compactness and the later strength of the steam‐cured concrete (see Figure 10); (b) the composite cementitious system composed of MK, FA, and GGBS could also significantly improve the ITZ properties of the steam‐cured concrete, to inhibit or eliminate the coarse pore structure 72–75 …”

Development of recycling techniques in 1st and 2nd generation waste photovoltaic panels

“…The white regions indicated the presence of chlorides due to silver chloride (AgCl) precipitation and the brown regions indicated the absence of chlorides, as AgNO3 reacted with hydroxide ions to form silver oxide (AgO) (Camarini et al, 2013).…”