Blast furnace slag cement

Type IS Pordand cement and blast furnace slag cement... 

Hogan, F.J., The effect of blast furnace slag cement on alkali aggregate reactivity a literature review, Cement Concrete and Aggregates, 7, 2, 1985. 

Mascolo, G. 1973. Hydration products of synthetic glasses similar to blast furnace slag. Cement and Concrete Research, 3, 207-213. 

Blast-furnace slag cements with high slag contents have lower heats of hydration than pure Portland cement, which is advantageous for large scale concrete structures (e.g. dams). The lower calcium hydroxide content results in their being somewhat more chemically stable than Portland cement. Blast-furnace slag cements are used in similar applications to Portland cement. 

The rate of reaction of blast furnace slag and fly ash differs strongly To show this. Figure 1.8 compares electrical resistivity measurements of wet cured concrete with a water/cement ratio of 0.45 made with Portland, Portland fly ash and blast furnace slag cements. The development of resistivity of concrete at an early age... 

Figure 2.6 Chloride profiles of a quay wall on vidual results of four cores (only symbols) the Dutch North Sea coast after 8 y of splash and best fitting profile according to zone exposure, blast furnace slag cement Eq. (4). described by = 1.77%, average of measured profiles (thin line), indi- D pp = 0.89 X 10rff/s...

Table 2.3 Resistivity [Cl m) of concrete made with Portland cement (OPC), blast furnace slag cement (GGBS), and Portland cement with addition of 5% silica fume (SF) iv/c = 0.45. lues were determined after 1.5—2.5 y exposure in a fog room or 20°C 80% R.H. climate [37]...

The degree of the attack by pure water depends to a large extent on the perme-abihty of the concrete, but its Ca(OH)2 content also plays an important role. Concrete types with a low level of Ca(OH)2, Hke blast furnace slag cement concrete, have improved resistance with regard to this type of degradation. In addition to... 

With regard to protection against sulfate attack, the quality of the concrete is a crucial factor a low permeability is the best defence against this type of attack, since it reduces sulfate penetration. This can be obtained by decreasing the w/c ratio and using blended cement (i. e. pozzolanic or blast furnace slag cement that reduce the calcium hydroxide content and refine the pore stracture of the matrix). Finally, the severity of the attack depends on the content of CjA and, to a lesser extent, of C4AF in the cement. Standards in different countries provide for sulfate resistant cements with a C3A content below 3-5 %. 

CO2 (molecular weight 44) that can react with a concrete produced with 300 kg/m Portland cement that we can suppose is composed by 64% of CaO (molecular weight 56) is 300 X 0.64 X 44/56 150 kg/m. In the case of blast furnace slag cement with 70 % of GGBS, the percentage of CaO is only 44%. For other blended cements, the quantity of CaO is somewhere between these two values [3]. For blended cement, hydration of pozzolanic materials or GGBS also leads to a lower Ca(OH)2 content in the hardened cement paste which may increase the carbonation... 

Table 12.5 Initiation time for chloride-induced corrosion estimated for different concrete cover thicknesses, utilising apparent diffusion coefficients of chlorides (D,pp) evaluated on specimens submerged in the North Sea for 16 y (concrete of 420 kg/m of Portland cement, OPC, or blast furnace slag cement with 70% GGBS and identical curing procedures) [18]...

With a few of the products that complied with all requirements described above, further investigations were carried out [23,24]. The conclusions apply to concrete of reasonable quality (wjc = 0.50) made with Portland or blast furnace slag cement, which was thought to be representative for the upper parts of bridge decks. They can be summarised as follows ... 

Dining manufacturing of cement-based pipeline products, the silicates and alumi-nates present in the cement react with water to form products of hydration and, in time, these set to a hard mass. The various solid phases formed come into thermodynamic equilibrium with the interstitial water (pore water), which is rich in calcium, sodium, and potassium hydroxide phases. The presence of these hydroxides raises the pH of the pore water solution to about 13 or 13.5. Table 4.15 gives typical compositions of pore solution for two types of cement Portland and blast furnace slag cement. 

De Schutter, G. (1999) Hydration and temperature development of concrete made with blast-furnace slag cement. Cement and Concrete Research 29,143-149. 

Marciano, E. Jr., and Battagin, A.F. (1997) The influence of alkah activator on the early hydration and performance of Portland blast furnace slag cement, in Proceedings 10th ICCC, Goteborg, paper 3iil03. 

Salem, Th.M., El-Didamony, H., and Mohamed, T.A. (1995) Studies on Portland blast furnace slag cement with limestone as a retarder. Indian Journal of Engineering Materials Science 21,32-135. 

Majumdar, A.J., Singh, B., and Edmonds, R.N. (1990) Hydration of mixtures of ciment fondue aluminous cement and granulated blast furnace slag. Cement and Concrete... 

As to the phase transformations, in blast furnace slag cement pastes increasing amounts of melilite [a sohd solution of gehlenite (C2AS) and akermanite (C2MS2)] are formed as the amount of slag in the original cement increases, at the expense of yff-dicalcium silicate, which is formed in Portland cement pastes under similar conditions. In pastes made from cements that contain distinct amoimts of fly ash, yff-dicalcium silicate is also the main final decomposition product. In parallel, quartz, which is a common constituent of fly... 

Figure 23.2 Content of bound water in cement pastes made with different cements and exposed to different temperatures. OPC, ordinary Portland cement BFSC, blast furnace slag cement with 50% of granulated blast furnace slag PFA, fly ash cement with 25% of pulverised fly ash Trass=trass cement with 25% of trass SF=Portland cement with 10% of added sihca fume.

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