The present work evaluates the performance of concrete, after four (4) years of placement in slabs on ground in Guatemala City, produced with the first LC3 [1, 2] Limestone-Calcined Clay cement in Guatemala, compared with concrete produced with a High Early Strength Portland Pozzolanic cement, commonly used in Ready Mix applications in the country. Three different concretes were evaluated: 1 with Portland Pozzolanic Cement (cement content of 292 kg/m3), 2 with LC3 (cement content of 292 kg/m3), and 3 with LC3 (cement content of 352 kg/m3). As expected, the Portland Pozzolanic cement concrete and the LC3 cement concrete with higher cement content, present much better compressive strength than the LC3 cement concrete with 292 kg/m3 cement content, especially at early ages. In durability tests, both concretes with LC3 cement present higher carbonation depth than the Portland Pozzolanic cement concrete. Nevertheless, both concretes with LC3 have a superior performance in resistance to chloride ion penetration. It is noted, that on a long-term basis, the Portland Pozzolanic Cement concrete improved considerably on this particular test, due to pozzolanic reaction. Although more tests are needed on concretes with LC3 cements, for the moment, and with the humidity conditions prevailing in Guatemala City, which are moderate, around 70%, and very prone to carbonation, it is recommended to continue to use concretes with Portland Pozzolanic cement. On the other hand, due to the good performance of concrete with LC3 cement on the chloride ion penetration test, this cement is recommended in high humidity environments, where carbonation is not an issue.