纳米碳酸钙颗粒对水泥水化性能和界面性质的影响

Effect of the Nano-CaCO_3 on Hydrated Properties and Interface of Cement Paste

研究了平均粒径为60nm的纳米碳酸钙颗粒,在不同的掺量下对普通水泥水化性能和界面性质的影响。研究结果表明,掺入2%的纳米碳酸钙颗粒可以明显改善水泥的早期水化强度,但是当掺量超过5%时,由于水泥含量的相对减少,其强度仍会逐渐下降。X射线衍射分析试验结果显示水化7d后内掺2%纳米碳酸钙颗粒的样品水泥矿物衍射峰强度略高于其他样品,表明纳米碳酸钙颗粒对早期水泥水化有一定的促进作用。掺入少量的纳米碳酸钙颗粒后,可以明显降低氢氧化钙在界面处的密集分布和定向排列,有助于改善界面的综合性能。扫描电子显微镜的试验结果也验证了纳米碳酸钙颗粒对界面的改善作用。

Effect of the nano-CaCO3 particle on hydrated properties and interface of cement paste was studied. The results show that the strength of early ages of cement paste with 2% nano-CaCO3 particle was higher than that of the cement paste without nano-CaCO3 particle But if the amount of nano-CaCO3 particle was higher than 5%, the strength of cement paste was decreased because of the decreasing amount of cement. Results of XRD show that the diffraction strength of hydrated production of cement paste with 2% nano-CaCO3 particle was higher than that of cement paste without nano-CaCO3 particle. This indicated that the hydration degree of cement paste at early ages could be accelerated by nano-CaCO3 particle. The dense distribution and beamed form of CH crystal at interface between cement paste and block was decreased when nano-CaCO3 particle was added shown by SEM. This validated that the interface could be meliorated by nano-CaCO3 particle.