## 4 Concluding Remarks
It exhibits indeed a lower affinity with polycarboxylate (PCE)-based superplasticizers compared to Welan gum. * Starch exhibits promise in enhancing shear-thinning behavior, apparent viscosity, and yield stress and reducing spreading diameter, presenting itself as a viable alternative to conventional VMAs such as Welan gum. * Alginate enhances workability by reducing spreading diameter and improving water retention in concrete. However, its inclusion reduces hardened-state properties due to weakened aggregate-cement paste bonds and increased water retention, leading to higher water demand and increased porosity. * Alginate serves also as a concrete durability enhancer, particularly as a self-healing agent for cracks, and has the ability to reduce ion diffusion. * Sodium alginate serves as an effective viscosity-modifying admixture in fluid concrete, surpassing raw brown seaweed alginate in performance due to its higher purity despite a higher cost. * Pectin enhances the viscosity of cement suspensions and their water retention capacity, in addition to concrete's plasticity and workability. * Pectin's improvements are due to calcium ion bindings, and promoting intermolecular associations through calcium bridges, but it depends, however, on the concentration of pectin and Ca2+. * The influence of carrageenanan biopolymers on cementitious suspensions varies not only according to the type and dosages used but also according to the presence or absence of HRWRs. * Incorporating kappa-carrageenanan in cement pastes results in a notable delay in setting, projected onto the reduction of the compressive strength due to reduced ion concentrations, which is further prolonged with increasing dosage, but this delay is mitigated by the addition of both kappa- and iota-carrageenanan, leading to a reduction in setting time. * _K. alvarezii_ enhances the viscosity and stiffness of cement-based materials, with comparable performance to kappa-carrageenanan at a dosage of 0.5%, although kappa-carrageenanan exhibits a superior enhancement of rigidity and build-up kinetics. Unlike kappa-carrageenanan, the seaweed causes no delays of the setting time. On the other hand, future research could concentrate on refining extraction methods, evaluating environmental impacts, and optimizing the synthesis and production processes of plant-based biopolymers. This focus would enhance their scalability and sustainability. Exploring new sources like agricultural waste or marine resources could broaden options and address supply chain challenges. Investigating the complex interactions between these biopolymers and cementitious matrix ions could optimize their performance in concrete formulations, leading to more efficient, eco-friendly, and cost-effective construction practices. Writing--review and editing, Y.B., M.H., K.B. and A.Y. All authors have read and agreed to the published version of the manuscript. The authors would like to express their gratitude for the financial support provided by the National Science and Engineering Research Council of Canada (NSERC) and the ten industrial partners participating in the NSERC Industrial Research Chair (IRC) on Development of Flowable Concrete with Adapted Rheology and Their Application in Concrete Infrastructures. Additionally, the research funds from Quebec's Advanced Materials Research and Innovation for the Development of Advanced Materials (PRIMA Quebec) for 3D Printing, held by Professor [PERSON] at the Universite de Sherbrooke, are also acknowledged. Not applicable. The authors declare no conflicts of interest.