Calcined clays play an important role when it comes to efficient supplementary cementitious materials (SCM) required in future. The substitution of clinker by calcined clays requires the application of water reducing agents to ensure a good workability of concrete due to high specific surface area and water demand of calcined clays. The interaction of two calcined clays with two lignosulfonate-based plasticizers was investigated in cement paste with respect to their dispersing and setting behavior. They exhibited a good correlation between higher substitution rates and higher required plasticizer dosages when the same dispersing effects are aimed at as for ordinary Portland cement. These high dosages result in partially significant retardation effects in hydration behavior. When same dosages are used for all investigated systems and workability effects are disregarded, the impact on cementitious systems with aluminum-rich calcined clays is in part significantly stronger than on pure cement paste. An optimized dosage respecting workability and setting behavior can lead to a promising combination of sustainable both SCM and plasticizer.    «

Calcined clays play an important role when it comes to efficient supplementary cementitious materials (SCM) required in future. The substitution of clinker by calcined clays requires the application of water reducing agents to ensure a good workability of concrete due to high specific surface area and water demand of calcined clays. The interaction of two calcined clays with two lignosulfonate-based plasticizers was investigated in cement paste with respect to their dispersing and setting behavi...    »