Schack Tobias, Strybny Bastian, Haist Michael
Institute of Building Materials Science, Leibniz University Hannover, 30167 Hanover, Germany.
Materials (Basel). 2024 Sep 13;17(18):4509. doi: 10.3390/ma17184509.
In this study, the impact of binder granulometry as well as chemical additives on the early strength and early age stiffness development of eco-efficient mortars with low clinker content and ternary blended cements with high contents of slag and limestone powder was investigated. With regard to granulometry, the particle size distribution of the slag was varied in two steps. In addition, admixtures based on nano-granular C-S-H seeds were used for the acceleration of the hydration reaction. Both the compressive strength at 1d and the in-situ ultrasound pulse velocity for the first 36 h were determined. The granulometric optimization of the slag leads to an improvement in compressive strength of up to 162% in the early phase of the first 24 h. In addition, C-S-H seeding enhanced the hydration reaction mortars as early as 6 h after water addition (at 20 °C). An increase in the dosage level of the C-S-H seeding admixture further resulted in a corresponding increase in early strength, particularly when the clinker content exceeds 30 wt% up to 103%. The proposed combined granulometric and admixture-based approach significantly improves the reaction of the binder in the early phase, so that the clinker factor can be significantly reduced while maintaining a comparable binder intensity.
在本研究中，研究了粘结剂粒度以及化学添加剂对低熟料含量的生态高效砂浆和高矿渣及石灰石粉含量的三元混合水泥的早期强度和早期刚度发展的影响。关于粒度，矿渣的粒度分布分两步变化。此外，基于纳米颗粒C-S-H晶种的外加剂用于加速水化反应。测定了1天的抗压强度和前36小时的现场超声脉冲速度。矿渣的粒度优化导致在最初24小时的早期阶段抗压强度提高高达162%。此外，C-S-H晶种早在加水后6小时（20℃）就增强了水化反应砂浆。C-S-H晶种外加剂用量水平的增加进一步导致早期强度相应增加，特别是当熟料含量超过30 wt%时，强度提高可达103%。所提出的结合粒度和外加剂的方法显著改善了早期粘结剂的反应，从而在保持可比粘结剂强度的同时，可以显著降低熟料系数。
