The Experts below are selected from a list of 3120 Experts worldwide ranked by ideXlab platform

Joshua R. Smith - One of the best experts on this subject based on the ideXlab platform.

Liang-ting Jiang - One of the best experts on this subject based on the ideXlab platform.

Engui Liu - One of the best experts on this subject based on the ideXlab platform.

  • Upcycling waste Seashells with cement: Rheology and early-age properties of Portland cement paste
    Resources Conservation and Recycling, 2020
    Co-Authors: Junjie Wang, Engui Liu
    Abstract:

    Abstract To reduce solid waste discharges into environment and virgin resource consumptions in construction, waste Seashells from seafood and aquaculture industry were recycled into powder form and reused in cementitious construction materials. This work aimed to use this biologically renewable waste material as a possible alternative to the nonrenewable limestone mineral used conventionally with Portland cement. The study explored roles of Seashell powder as both a partial replacement and an additional additive to cement through evaluating the rheological and physico-mechanical properties of early-age cement paste. The cyclic rheological measurement including model analysis (Bingham, Casson, and Herschel-Bulkley models) was conducted to reveal the time- and shear-dependent workability of fresh cement paste during the first 2 h. Connecting to rheology, physico-mechanical measurements were carried out to understand hydration mechanisms of cement paste with Seashell powder. Seashell powder was found to improve the rheological and early hydration behaviors of Portland cement paste. A parallel comparison between limestone and Seashell powders was conducted to understand different roles of the two calcium carbonate minerals in cement system. Results from this study indicated the unique physical features and chemical reactivities of Seashell powder in cement system, and thus suggested a promising feasibility to recycle waste Seashells with cementitious construction materials.

  • characterization on the recycling of waste Seashells with portland cement towards sustainable cementitious materials
    Journal of Cleaner Production, 2019
    Co-Authors: Junjie Wang, Engui Liu, Liang Li
    Abstract:

    Abstract This work introduces a cleaner production practice of transforming waste Seashells into new minerals for sustainable cementitious materials. Waste Seashells were recycled into fine powder through regular crushing and ball-milling processes. Multi-scale studies characterized systematically the reaction mechanisms of waste Seashell powder in ordinary Portland cement system. Seashell powder was studied as both a cement replacement and an additional mineral filler, and its roles were explored through workability of fresh cement mixtures, hydration of cement, and mechanical behaviors of hardened cement mixtures. The results indicated that Seashell powder enhanced the hydration of cement through its physical and chemical interactions with both cement clinker phases and hydration products. The mechanical strength of hardened cement mixtures was directly improved when the Seashell powder was used as an additional filler. Additions of Seashell powder, either as a cement replacement or an additional filler, modified the rheological behaviors of fresh cement mixtures. The hydrated C S H matrix phases developed with Seashell powder were clearly enriched by the embedded well-dispersed nanosized clusters (with diameter around 5–10 nm). Parallel comparisons between Seashell powder and limestone powder confirmed the higher surface properties and chemical reactivities of Seashell powder than limestone powder in cement system.

Junjie Wang - One of the best experts on this subject based on the ideXlab platform.

  • Upcycling waste Seashells with cement: Rheology and early-age properties of Portland cement paste
    Resources Conservation and Recycling, 2020
    Co-Authors: Junjie Wang, Engui Liu
    Abstract:

    Abstract To reduce solid waste discharges into environment and virgin resource consumptions in construction, waste Seashells from seafood and aquaculture industry were recycled into powder form and reused in cementitious construction materials. This work aimed to use this biologically renewable waste material as a possible alternative to the nonrenewable limestone mineral used conventionally with Portland cement. The study explored roles of Seashell powder as both a partial replacement and an additional additive to cement through evaluating the rheological and physico-mechanical properties of early-age cement paste. The cyclic rheological measurement including model analysis (Bingham, Casson, and Herschel-Bulkley models) was conducted to reveal the time- and shear-dependent workability of fresh cement paste during the first 2 h. Connecting to rheology, physico-mechanical measurements were carried out to understand hydration mechanisms of cement paste with Seashell powder. Seashell powder was found to improve the rheological and early hydration behaviors of Portland cement paste. A parallel comparison between limestone and Seashell powders was conducted to understand different roles of the two calcium carbonate minerals in cement system. Results from this study indicated the unique physical features and chemical reactivities of Seashell powder in cement system, and thus suggested a promising feasibility to recycle waste Seashells with cementitious construction materials.

  • characterization on the recycling of waste Seashells with portland cement towards sustainable cementitious materials
    Journal of Cleaner Production, 2019
    Co-Authors: Junjie Wang, Engui Liu, Liang Li
    Abstract:

    Abstract This work introduces a cleaner production practice of transforming waste Seashells into new minerals for sustainable cementitious materials. Waste Seashells were recycled into fine powder through regular crushing and ball-milling processes. Multi-scale studies characterized systematically the reaction mechanisms of waste Seashell powder in ordinary Portland cement system. Seashell powder was studied as both a cement replacement and an additional mineral filler, and its roles were explored through workability of fresh cement mixtures, hydration of cement, and mechanical behaviors of hardened cement mixtures. The results indicated that Seashell powder enhanced the hydration of cement through its physical and chemical interactions with both cement clinker phases and hydration products. The mechanical strength of hardened cement mixtures was directly improved when the Seashell powder was used as an additional filler. Additions of Seashell powder, either as a cement replacement or an additional filler, modified the rheological behaviors of fresh cement mixtures. The hydrated C S H matrix phases developed with Seashell powder were clearly enriched by the embedded well-dispersed nanosized clusters (with diameter around 5–10 nm). Parallel comparisons between Seashell powder and limestone powder confirmed the higher surface properties and chemical reactivities of Seashell powder than limestone powder in cement system.

Shaliza Ibrahim - One of the best experts on this subject based on the ideXlab platform.

  • fabrication of Seashell incorporated polyurethane for sustainable remediation of fe ii contaminated acidic wastewater
    Journal of Polymers and The Environment, 2019
    Co-Authors: Choe Earn Choong, Gooyong Lee, Min Jang, Chang Min Park, Shaliza Ibrahim
    Abstract:

    In this study, Seashell-incorporated polyurethane (SPU) was synthesized for sustainable remediation of Fe(II)-contaminated acidic wastewater. Several batch and column experiments were conducted to find optimal Seashell/PU ratio, particle size, bed volume and retention time. Seashell/PU ratio of 20 wt%, with high chemical stability, was found to be the optimum proportion with maximum Fe(II) removal capacity of 277.1 mg-Fe(II)/g-Seashell. The primary removal mechanisms were adsorption and precipitation as ferric hydroxide and ferric carbonate. Crushed Seashell with the particle diameter of 0.13 mm ≤ O < 0.15 mm posed the highest Fe(II) removal capacity. SPU, with the enhanced hydro-conductivity of the crushed Seashell, showed consistent Fe(II) removal capacity (237.5 mg-Fe(II)/g-Seashell) in both batch and column experiments. Large bed volumes increased Fe(II) removal efficiency, but the increment was not directly proportional to the removal efficiency. The breakthrough curve was also found to fit well to Yoon–Nelson Kinetic model and Thomas kinetic model with the determination coefficient of 0.867–0.987. In overall, SPU can be considered as a sustainable alternative for a low-cost absorbent for heavy metal contaminated acidic wastewater.

  • Fabrication of Seashell-Incorporated Polyurethane for Sustainable Remediation of Fe(II)-Contaminated Acidic Wastewater
    Journal of Polymers and the Environment, 2018
    Co-Authors: Choe Earn Choong, Gooyong Lee, Min Jang, Chang Min Park, Shaliza Ibrahim
    Abstract:

    In this study, Seashell-incorporated polyurethane (SPU) was synthesized for sustainable remediation of Fe(II)-contaminated acidic wastewater. Several batch and column experiments were conducted to find optimal Seashell/PU ratio, particle size, bed volume and retention time. Seashell/PU ratio of 20 wt%, with high chemical stability, was found to be the optimum proportion with maximum Fe(II) removal capacity of 277.1 mg-Fe(II)/g-Seashell. The primary removal mechanisms were adsorption and precipitation as ferric hydroxide and ferric carbonate. Crushed Seashell with the particle diameter of 0.13 mm ≤ O