Rheological study of Portland cement pastes modified with superabsorbent polymer and nanosilica

Agostinho, Lívia B.; Alexandre, de C. Pereira; Silva, Eugênia Fonseca da; Filho, Romildo Dias Tolêdo

doi:10.1016/j.jobe.2020.102024

Cited by 21 publications

(11 citation statements)

References 25 publications

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“…In other words, the substantial increase in water dosage, consequent voids formation due to SAP swelling, and adverse effect of SAPs on the rheology properties are viewed as major factors that contribute to the strength loss. Obtained findings are in agreement with the findings of Agostinho et al [ 51 ], who have found 0.3–1 wt.% as a threshold for the preservation of rheological properties. However, dosage strongly corresponds with the type of used SAP.…”

Section: Resultssupporting

confidence: 93%

Functional Properties of SAP-Based Humidity Control Plasters

et al. 2021

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The application of materials with high moisture storage capacity close to the interior surface presents a prospective passive method for improving indoor relative humidity conditions. In this paper, lime-cement plasters containing three different types of superabsorbent polymers (SAPs) in varying dosages are introduced and their mechanical, hygric, and thermal characteristics are analyzed in a relation to microstructure. The experimental results show a significant effect of both SAP amount and chemical composition on all functional properties of studied plasters. The incorporation of 1.5% of SAP may induce up to 2.5 better moisture buffering, thus significantly improving the passive humidity control capability. Considering overall functional parameters of SAP-modified plasters, the dosage of 1 wt.% can thus be viewed as a rational compromise between the moisture storage capability and mechanical properties. The obtained wide sets of parameters can be utilized directly as input data of computational models suitable for the assessment of the interior microclimate of residential and administrative buildings.

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Section: Resultssupporting

confidence: 93%

Functional Properties of SAP-Based Humidity Control Plasters

et al. 2021

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“…The large LS particle extended the skeleton space of the paste, the cement particles filled the particle space of the skeleton space of the LS, and the USL particles filled the space between the cement particles, leading to a decrease in the shear thickening and the yield stress [ 32 , 33 ]. Increasing the USL content increased the adsorption of the water reducing agent and its agglomeration effect, which maintained the positive impact imposed by the increase in free water and influenced the degree of shear thickening [ 34 ]. Moreover, when 30% of the cement was replaced by LS, the LS particles increased the skeleton space of the paste, which needed more cement paste to fill and resulted in smaller spaces not being filled [ 35 ].…”

Section: Resultsmentioning

confidence: 99%

The Synergistic Effects of Ultrafine Slag Powder and Limestone on the Rheology Behavior, Microstructure, and Fractal Features of Ultra-High Performance Concrete (UHPC)

et al. 2023

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This study investigated the effect of the interaction between ultrafine slag powder (USL) and limestone (LS) on the rheology behavior, microstructure, and fractal features of UHPC. The results indicated that B2 with mass ratio of 2:1 between the USL and LS obtained the highest compressive strength and the lowest yield stress. The combination of the USL and LS facilitated the cement hydration, ettringite, and monocarboaluminate (Mc) formation, as well as the increase in the polymerization of the C–S–H. The synergistic action between the USL and LS refined the pore structure due to the formation of the Mc, compensating for the consumption of the CH by the pozzolanic reaction, which provided a denser microstructure in the UHPC. The fractal dimension (Ds) of the UHPC was strongly related to the concrete pore structures and the compressive strength, which demonstrated that a new metric called the Ds value may be used to assess the synergistic effect of the UHPC.

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“…Previous researchers have found that ramp 1 and ramp 2 should not be taken into consideration because of their strange rheological characteristics. 35 Moreover, the uniform mixing of solid grains and polymer molecules has not been achieved in ramp 1 and ramp 2. 36 Thus, the mean value of the last two ramp cycles was used to analyze the rheological properties of cement paste.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

“…In each cycle, the shear speed increased from 0 to 100 rpm in 1 min and then decreased from 100 to 0 rpm in 1 min. Previous researchers have found that ramp 1 and ramp 2 should not be taken into consideration because of their strange rheological characteristics . Moreover, the uniform mixing of solid grains and polymer molecules has not been achieved in ramp 1 and ramp 2 .…”

Section: Methodsmentioning

confidence: 99%

Effect of a Cationic Polymer on the Rheology of Cement Pastes Containing Na-Bentonite

Wen

Feng²,

Zheng

2023

Langmuir

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This paper studies how a cationic polymer affects the rheological properties of cement pastes containing Nabentonite in the presence of a polycarboxylate superplasticizer (PCE), and the fluidity was also investigated. The Herschel− Bulkley model was applied to fit the rheological data of cement pastes at the beginning and after 1 and 3 h. The results show that the cement pastes exhibit a significant increase in fluidity and turn to be a shear-thickening fluid with the addition of the cationic polymer KN, as indicated by the pseudoplastic index n. The yield stress and plastic viscosity of cement pastes containing Nabentonite obviously decrease with the addition of KN. Statistical analysis was performed to evaluate the impact of KN and PCE on the rheological properties. PCE exhibits a significant influence on both yield stress and plastic viscosity, while KN also exerts an obvious effect on the yield stress for cement pastes containing minor amounts of PCE. The equations for yield stress and plastic viscosity are obtained, which will allow us to predict the yield stress and plastic viscosity of cement pastes containing various contents of PCE and KN.

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Rheological study of Portland cement pastes modified with superabsorbent polymer and nanosilica

Cited by 21 publications

References 25 publications

Functional Properties of SAP-Based Humidity Control Plasters

Functional Properties of SAP-Based Humidity Control Plasters

The Synergistic Effects of Ultrafine Slag Powder and Limestone on the Rheology Behavior, Microstructure, and Fractal Features of Ultra-High Performance Concrete (UHPC)

Effect of a Cationic Polymer on the Rheology of Cement Pastes Containing Na-Bentonite

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