Controlling an unconventional path of hydration opens the doors for novel performance and applications

Abstract

A novel admixture‐based approach has been developed to control the kinetics of early hydration reactions in ordinary Portland cement (OPC) systems. The admixture influences both the dissolution of anhydrous cement phases and the nucleation and growth of the first hydration products. By adjusting dosage and formulation, the dissolution rate and degree of the anhydrous phases can be precisely modulated. Synergistic interactions between the individual components govern the nucleation of key hydrates, such as ettringite, enabling targeted modification of early hydration pathways.

This control at the microscopic level directly translates into improved macroscopic performance, including adjustable setting behavior (set‐on‐demand), rapid early strength development, enhanced sulfate resistance, and reduced shrinkage.

Among modern construction methods, 3D concrete printing (3DCP) represents one of the most demanding applications due to conflicting fresh‐state requirements. Sufficient extrudability must be maintained while rapid structural build‐up is required after deposition, necessitating precise control of early hydration kinetics.

This study demonstrates how a two‐component (2K) admixture technology provides a flexible solution to these challenges. Its application in 3DCP validates the ability to dynamically regulate hydration kinetics during printing, ensuring process stability and high print quality. Beyond additive manufacturing, the approach highlights the broader potential of controlled hydration for sustainable and cost‐effective solutions in conventional applications such as precast concrete and shotcrete tunneling.