Raman spectroscopic investigation of Friedel's salt

Abstract

This is a repository copy of Raman spectroscopic investigation of Friedel's salt.

Reuse of coal mining waste to lengthen the service life of cementitious matrices

“…Despite the scantly uniform data distribution, the inclusion of ACMW clearly lowered the chloride threshold value, particularly at a replacement ratio of chloride front in specimens where corrosion was already under way, triggered in mortars ACMW20 and ACMW50, apparently, as soon as the front reached the reinforcement depth. As noted earlier, ACMW blended matrices have been shown to bind chloride ions by forming Friedel's salt [26], thereby reducing the amount of free chloride ions in the system and with it the risk of corrosion [22,42]. The inference would initially be that the chloride threshold, expressed as total chloride concentration, would be higher with ACMW.…”

“…Significant gaps nonetheless persist in the scientific understanding of the durability of these new eco-efficient binary cements. One of the most common causes of reinforced concrete decay is reinforcement corrosion induced by chloride ion penetration in the matrix [21,22]. The passivated layer forming on the surface of steel bars thanks to the highly alkaline pore solution in concrete protects them from corrosion.…”

Correlation between diffusion coefficient values of chloride ions obtained through column and ion migration tests in cementitious matrices with varying contents of silica fume and mortar

“…The presence of alumina (4.84%) is associated with C 4 AF (tetra-calcium aluminate iron) and C 3 A (tricalcium aluminate) phases. According to Shi et al [18], Ribeiro et al [5], and Yue et al [19], the aluminate content delays the non-steady state diffusion of chlorides due to the formation of chloroaluminates in the concrete microstructure, in particular Friedel's salt (C 3 A⋅CaCl 2 ⋅10H 2 O). In the chemical composition of the silica fume, mainly silica (SiO 2 ) is observed along with impurities such as zinc oxide (ZnO) and manganese oxide (MnO).…”

Establishing the Carbonation Profile with Raman Spectroscopy: Effects of Fly Ash and Ground Granulated Blast Furnace Slag

“…Besides, no research has been carried out on the Raman spectroscopic investigation of the carbonation in blended cement materials containing supplementary cementitious materials (SCMs) (e.g., fly ash (FA), ground granulated blast furnace slag (GGBS)), let alone establishing the carbonation profile in the blended cementitious matrices. In recent years, the authors have carried out extensive research to apply both bench-mounted Raman spectroscopy and the optical fiber Raman technique in cement and concrete, covering the different aspects related to cementitious materials such as the anhydrous phases and hydration products as well as the deteriorated phases/products [ 22 , 23 , 24 , 25 , 26 ]. It is worth highlighting that previous works have successfully developed bespoke optics-tailored fiber optic Raman systems for characterizing the carbonation products of concrete.…”