Heat of Hydration Results

Figure 4 shows two different initial cement particle images, both at a w/c of 0.45. The area and perimeter fractions for these two cement images are provided in Table 2.

In Figure 5, calculated heat of hydration is plotted versus calculated degree of hydration for results obtained using the microstructure model to hydrate each cement for 200 cycles. As expected, a basically linear relationship is observed between heat evolved and degree of hydration. Since the two cements differ in bulk and surface compositions as shown in Table 2, their heat release characteristics also vary. Because Cement 1 has a higher C₃ A content and C₃A has a higher heat of hydration than the other clinker phases [10], it releases more heat during hydration than Cement 2.

Figure 4. Computer-assembled 250*250 µm (500*500 pixel) images of initial cement particles for two cements, both with a w/c of 0.45. Color scheme is the same as in Figure 3. Cement 1 contains a higher fraction of C₃A (bright green) than Cement 2.

Figure 5. Heat of hydration curves calculated for the two cements shown in Figure 4.