The addition of calcium carbonate nanoparticles (nano‐CaCO₃) accelerates the hydration of Portland cement improving its mechanical properties. Conversely, nano‐CaCO₃ addition leads to reduction in the water required during initial PC hydration. Therefore, the use of a correct water‐to‐powder ratio is fundamental for manipulating this hydraulic cement. This study evaluated the effect of nano‐CaCO₃ addition and different water‐to‐powder ratios on the physicochemical properties of white Portland cement (WPC). WPC was associated to different concentrations of nano‐CaCO₃, and the following experimental groups were created: G1a (no nano‐CaCO₃); G2a (0.5% nano‐CaCO₃), G3a (1% nano‐CaCO₃), G4a (2% nano‐CaCO₃), and G5a (5% nano‐CaCO₃). The setting‐time (ST), compressive strength (CS), dimensional change (DC), solubility (S), and pH were assessed (24 hr and 30 days). Next, WPC + 5% nano‐CaCO₃ was manipulated varying the water‐to‐powder ratio: G1b (WPC/0.33 ml); G2b (WPC/nano‐CaCO₃/0.33 ml); G3b (WPC/0.29 ml); G4b (WPC/nano‐CaCO₃/0.29 ml); G5b (WPC/0.26 ml); and G6b (WPC/nano‐CaCO₃/0.26 ml). The tests were repeated. The data analysis (2‐way ANOVA and Tukey test, α = 5%) demonstrated that ST was shorter for samples containing nano‐CaCO₃ (p < .05). Reduction in CS was observed for all groups at 30 days, except G5a, G2b, and G6b (p < .05). DC and S had no statistical difference among groups (p > .05) independently of nano‐CaCO₃ water‐to‐powder ratio. After 30 days, there was significant reduction in pH for G3a and G6b (p < .05). The different concentrations of nano‐CaCO₃ and water‐to‐powder ratios affected the physicochemical properties of WPC, especially the setting‐time and compressive strength.

中文翻译：

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添加碳酸钙纳米颗粒和不同水灰比对白硅酸盐水泥理化性质的影响

添加碳酸钙纳米颗粒（nano-CaCO ₃）可以加速硅酸盐水泥的水合作用，从而改善其机械性能。相反，添加纳米CaCO ₃可减少初始PC水合过程中所需的水量。因此，使用正确的水粉比是处理这种水硬性水泥的基础。这项研究评估了添加纳米CaCO ₃和不同水灰比对白色硅酸盐水泥（WPC）的理化性质的影响。WPC与不同浓度的nano-CaCO _3相关，并创建了以下实验组：G1a（无nano-CaCO ₃）；G2a（0.5％纳米CaCO ₃），G3a（1％纳米CaCO₃），G4a（2％nano-CaCO ₃）和G5a（5％nano-CaCO ₃）。评估了凝固时间（ST），抗压强度（CS），尺寸变化（DC），溶解度（S）和pH（24小时30天）。接下来，通过改变水粉比：G1b（WPC / 0.33 ml）来控制WPC + 5％纳米CaCO ₃。G2b（WPC /纳米CaCO ₃ /0.33毫升）; G3b（WPC / 0.29毫升）; G4b（WPC / nano-CaCO ₃ /0.29 ml）; G5b（WPC / 0.26毫升）; 和G6b（WPC / nano-CaCO ₃ /0.26 ml）。重复测试。数据分析（双向方差分析和Tukey检验，α = 5％）表明，含有纳米CaCO ₃（p <.05）。除G5a，G2b和G6b外，所有组在第30天的CS均降低（p  <.05）。DC和S在各组之间无统计学差异（p  > .05），与nano-CaCO ₃水粉比无关。30天后，G3a和G6b的pH值明显降低（p  <.05）。纳米CaCO ₃浓度和水粉比的不同会影响WPC的理化特性，特别是凝固时间和抗压强度。