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The increasing use of geopolymer materials in the construction and civil engineering sectors generates a large amount of non-biodegradable waste that will end up in landfills. It is therefore necessary to anticipate solutions for the proper management of this waste. In this work, new geopolymer materials were fabricated by partially replacing the reactive raw minerals (fly ash, FA, or metakaolin, MK) with used geopolymers (fully fly ash-based, FAref, or metakaolin-based, MKref), in order to develop a strategy to reuse geopolymer waste. Their workability and setting behavior were studied in the fresh state, and the geopolymerization process was investigated by calorimetry and by electrochemistry. Mechanical properties and the ability for coating mineral aggregates were assessed, and the resulting adhesion properties were analyzed using matrix/sand mortars. It appears that the new geopolymer materials as well as the mortars are endowed with good performances. The compressive strengths are above 50 MPa and therefore meet the requirements of different construction materials. This demonstrates the recyclability of geopolymer materials. Moreover, an analysis of the influence of the substitution of recycled geopolymers on the setting and on the mechanical performances of mortars makes it possible to propose a binder-recycled geopolymer interaction model for the formation of new binding matrices.
Rabii Hattaf; Abdelilah Aboulayt; Azzedine Samdi; Nouha Lahlou; Mohamed Ouazzani Touhami; Moussa Gomina; Redouane Moussa. Reusing Geopolymer Waste from Matrices Based on Metakaolin or Fly Ash for the Manufacture of New Binder Geopolymeric Matrices. Sustainability 2021, 13, 8070 .
AMA StyleRabii Hattaf, Abdelilah Aboulayt, Azzedine Samdi, Nouha Lahlou, Mohamed Ouazzani Touhami, Moussa Gomina, Redouane Moussa. Reusing Geopolymer Waste from Matrices Based on Metakaolin or Fly Ash for the Manufacture of New Binder Geopolymeric Matrices. Sustainability. 2021; 13 (14):8070.
Chicago/Turabian StyleRabii Hattaf; Abdelilah Aboulayt; Azzedine Samdi; Nouha Lahlou; Mohamed Ouazzani Touhami; Moussa Gomina; Redouane Moussa. 2021. "Reusing Geopolymer Waste from Matrices Based on Metakaolin or Fly Ash for the Manufacture of New Binder Geopolymeric Matrices." Sustainability 13, no. 14: 8070.
In this work, we are interested in describing the evolution of the rheological behavior of geopolymer materials since their elaboration until the start of their kinetics of setting. We considered the case where these materials are obtained from the dissolution of a quantity S of metakaolin in a quantity L of alkaline activation solution (sodium-based). In this context and for all the values of the structural identification parameters P = (% Na2O) and R3 = (L/S) in our experiments, it has been established that the rheological behavior is described by the viscoplastic Herschel-Bulkley model. In particular, we have been able to determine how rheological parameters of the model are affected by variations of P and / or R3. For the considered formulations, this analysis is of importance insofar as it was at the base of the identification of critical values of P and R3. Moreover, we verified that for these values, the setting time is maximum. This result is retained to define the optimized formulation of our materials.
Nouha Lahlou; Mohamed Ouazzani Touhami; Rabii Hattaf; Redouane Moussa. Towards an optimization of the formulation of geopolymers in the fresh state: Rheological approach. Applied Rheology 2019, 29, 94 -104.
AMA StyleNouha Lahlou, Mohamed Ouazzani Touhami, Rabii Hattaf, Redouane Moussa. Towards an optimization of the formulation of geopolymers in the fresh state: Rheological approach. Applied Rheology. 2019; 29 (1):94-104.
Chicago/Turabian StyleNouha Lahlou; Mohamed Ouazzani Touhami; Rabii Hattaf; Redouane Moussa. 2019. "Towards an optimization of the formulation of geopolymers in the fresh state: Rheological approach." Applied Rheology 29, no. 1: 94-104.
It is established that the rheological properties of polyethylene oxide solutions are related to the concentration, molecular weight, nature of the solvent, external stresses such as temperature and pressure and microstructural interactions. The main objective of this study is to carry out the effect of the concentration of aqueous PEO solutions on their rheological behavior. In this context, we consider quasi-stationary, transient and oscillatory flow regimes for three values of concentrations (250 ppm, 500 ppm and 1000 ppm). Except the case where the solution is Binghamian (250 ppm), we denote that for quasi-stationary mode, the observed behaviors correspond to a rheofluidifying fluids with yield stress. The model adapted from Rheowin Software is Herschel-Bulkley for whicha yield stress and consistency increases and a flow indexdecreases when the concentration increases. The studies of these solutions under transient and subsequently under oscillating conditions are made to specify their viscoelastic properties. For a concentration less than 500 ppm the viscoelastic nature is described by the Maxwell model and by the Jeffrey model for a concentration of 1000 ppm. Otherwise, and for the oscillating test, the determination of the evolution of the critical frequency fc (for which the conservation factor G ʹand the loss factor Gʹ ʹare comparable) as a function of the concentration consolidates the actual control protocols of PEO aqueous solutions and allows to optimize the processes of their use in industrial environment.
N Lahlou; M Riahi; Saïd Aniss; M Ouazzani Touhami. Control of the effects of the concentration on the viscoelastic behavior of the aqueous Polyethylene-Oxide solution. Journal of Physics: Conference Series 2018, 1045, 012025 .
AMA StyleN Lahlou, M Riahi, Saïd Aniss, M Ouazzani Touhami. Control of the effects of the concentration on the viscoelastic behavior of the aqueous Polyethylene-Oxide solution. Journal of Physics: Conference Series. 2018; 1045 (1):012025.
Chicago/Turabian StyleN Lahlou; M Riahi; Saïd Aniss; M Ouazzani Touhami. 2018. "Control of the effects of the concentration on the viscoelastic behavior of the aqueous Polyethylene-Oxide solution." Journal of Physics: Conference Series 1045, no. 1: 012025.