Impact of different superplasticizers on hydration, rheology, mechanical strength, and environmental evaluation of LC3 cements

The mineralogical and physicochemical characteristics of the clay can adversely affect the efficiency of polycarboxylate-based superplasticizers, limiting their dispersion capacity. This challenge has increasingly drawn attention within the field of LC 3 research. In this context, the present study investigated the effect of different dosages (0.25% and 0.50% by weight of anhydrous) of a conventional polycarboxylate ether (PCE) and a modified polycarboxylate formulation combined with a clay-mitigating agent (PCE + CM) on the fresh and hardened properties of LC 3 cement pastes. The molecular structure of these polymers played a crucial role in optimizing the performance of the cementitious matrices. The findings revealed that the PCE + CM admixture provided effective adsorption and rheological performance even at low dosages (7.84 Pa), without negatively impacting the hydration kinetics. Moreover, the mechanical strength (44.14 - 47.93 MPa) and environmental indicators of the LC 3 mixtures with PCE + CM were comparable to or exceeded those of ordinary Portland cement (OPC) and the reference LC 3 formulation. These results highlight the potential of clay-mitigating admixtures to overcome dispersion challenges in LC 3 systems, supporting their scalability and further encouraging the adoption of LC 3 cement as a sustainable alternative in the construction industry.