Evolution of CCRL 168 cement paste microstructure: (a) hydrated to 0.90 degree of hydration; (b) end of Stage 1, when monosulfatehas been converted to ettringite; (c) end of Stage 2, when all carboaluminates have been converted to ettringite; (d) magnified view of a portion of the microstructure in (c) showing the deformation around secondary ettringite. The displacement field is magnified by 5× to more clearly show deformation. Phase colors are C3S = brown, C2S = light blue, C3A = grey, C4AF = white, CSH = beige, CH = dark blue, calcite = green, ettringite = violet, monosulfate = olive, hydrotalcite = light green, capillary porosity = black.