Antifreezing admixtures

Ramachandran, V. S., Calcium Chloride in Concrete-Science and Technology, p. 216, Applied Science Publishers, London (1981) 

Tanoutasse, N., The Hydration Mechanism of C3 A and C3S inthe Presence of Calcium Chloride and Calcium Sulphate, 5th Int. Symp. Chem. Cements, Part 2, pp. 372-378, Tokyo (1968) 

Mukhegi, K., and Ludwig, U., Influence of Addition of Calcium Chloride and Calcium Sulphate on the Rate of Hydration of C3S and P-C2S, Tonind. Ztg., 97 211-216(1973) 

Skalny, J., and Maycock, J. N., Mechanisms of Acceleration by Calcium Chloride—A Review, 77th Annual Meeting, ASTM, Washington, DC, (June 1974) 

Collepardi, M., and Massida, L., Hydration of Tricalcium Silicate in Suspension, di Chimica, 61 160-168 (1971) 

---

Accelerator in Ready-Mix Concrete. Calcium chloride accelerates the set time of concrete giving it a high early strength development. It is not an antifreeze, but by using it duriag cold weather protection can proceed in a timely manner (31—34). In Russia, calcium chloride forms a component of several antifreeze admixtures (33). Reviews of the concerns and possible remedies of calcium chloride corrosion problems in concrete are available (21,35). There is no consensus on what the safe levels of calcium chloride in concrete are. 

In addition to the two basic groups of antifreeze admixtures, others containing superplastizisers such as sulfonated naphthalene formaldehyde (SNF) and sulfonated melamine formaldehyde (SMF) have been developed. The main advantage afforded by such admixtures is that they produce significant water-reduction. 

The water reduction afforded (about 20-25%) reduces the freezable free water content which usually serves as a heat sink for the heat liberated by the initial hydration reactions. Hence, lower amounts of antifreeze admixtures can be used. 

Table 6.5 Strengths of concrete containing some binary antifreezing admixtures at 10°C (Ratinov and Rosenburg)...

A resume of the use of antifreeze admixtures has been presented to make the reader aware of these admixtures. The writer is, however, cognizant that more specific information will be required for those interested in their application. Readers who require greater detail are directed to reference [24], which is an exhaustive treatment of the subject. 

Korhonen, C. J. (1990). Antifreezing Admixtures for Cold Regions Concreting, a Literature Review, Special Report, CRREL 90-32, 14. 

Similarly, in plastic concrete, the presence of dissolved calcium, sodium, potassium and sulfate ions lowers slightly the freezing point of pore water, which begins to crystallize as ice at a concrete temperature of about -2° C (28°F) [110]. The addition of the proper combination of salts such as those contained in antifreeze admixtures can further reduce the temperature at which ice formation begins. 

Table 7.23 Eutectic point characteristics for some Russian antifreeze admixtures (Ratinov et al.)...

Table 11. Strength Gain in Concrete Containing Antifreezing Admixtures...

---