Obtainment of Hybrid Composites Based on Hydrogel and Portland Cement

Santos, J.C. dos; Tashima, Mauro M.; Moura, Márcia R. de; Aouada, Fauze A.

doi:10.5935/0100-4042.20160005

Cited by 6 publications

(12 citation statements)

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“…With the material completely dry, it was again ground and stored until its application. All concentrations of the required reagents were pre-established by our research group GCNH (Grupo de Compósitos e Nanocompósitos Híbridos) [ 42 ].…”

Section: Methodsmentioning

confidence: 99%

“…The hydrogel concentration (0.5% wt/wt in relation to cement mass) was determined according to the results obtained in previous researches [ 42 ]. It is important to mention that all the hydrogels were presoaked with water until the equilibrium state (48 h), to ensure that the hydrogel was completely charged with water when it was applied to the mortar.…”

Section: Methodsmentioning

confidence: 99%

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Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars

et al. 2022

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Hybrid nanocomposite hydrogels, as admixtures for internal curing of cementitious materials, have been widely studied. This study analyzes the effect of applying 0.5% (wt/wt cement) of pre-soaked hydrogels based on polyacrylamide, carboxymethylcellulose, and three different concentrations of Cloisite-Na+ (0, 10, and 20% wt/wt) on the fresh and hardened properties of cementitious mortars. In general, all mortars with hydrogel decreased the consistency index, mainly M20, due to the high concentration of Cloisite-Na+ that modifies the release kinect of the hydrogel. The results showed a slight variation, with an overall average value of 99% water retention in all mortars. This behavior is due to the portion of hydrogel-mortars dosage water retained to reduce the availability of free water in the mixture because this amount of water is stored, a priori, within the polymer particles. At 28 d, the mortars produced with hydrogels containing 20% of nanoclay (M20) exhibit mechanical behavior similar to the reference mortar (M), which corroborates the percentage of voids found. Scanning electron microscope images confirm that the M and M20 mortars are uniform and possess few pores or microcracks. Thus, these hybrid hydrogels have the potential to be innovative materials for water control improvements in cementitious materials technology.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars

et al. 2022

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“…The hydrogels were obtained by chemical polymerization of AAm monomer in an aqueous solution containing cloisite-Na + nanoclay, CMC, MBAAm crosslinking agent, and TEMED catalyst following the procedure described by Santos et al [8] In our study, the hydrogel formulation was 5% AAm (m/v), 2% MBAAm (mol relative to AAm monomer), 0.75% CMC (m/v), and 10% nanoclay cloisite-Na + (mass %) (concerning to AAm + CMC mass).…”

Section: Preparation Of Hydrogels and Cement Portland Based Compositesmentioning

confidence: 99%

“…[5,7] Recent research highlights that the development DOI: 10.1002/masy.202000047 of new materials has allowed the inclusion of chemical concepts in civil construction, more specifically, in the production of special concretes, improving the setting time, reducing the porosity of the matrices, and other benefits. [8] Thus, for the production of cementitious matrix composites, a better control of mechanical (such as strength and modulus of deformation), exudation, durability, and permeability properties is desired, what may contribute to increasing its life cycle. In the cementitious materials, the particles of the binder have a high tendency to agglomerate due to its elevate van der Waals and electrostatic forces.…”

Section: Introductionmentioning

confidence: 99%

“…In the cementitious materials, the particles of the binder have a high tendency to agglomerate due to its elevate van der Waals and electrostatic forces. [8] Besides, the presence of this agglomerated implies in the retention of a certain amount of free water, forming open channels between the particles, thus decreasing the hydration of surfaces of the cement particles. The addition of additives to concrete, mortar, or paste becomes an interesting alternative to improve the physicochemical properties and workability of these matrices.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Hydrogel Nanocomposites on the Fresh and Hardened Properties of Cementitious Pastes

Siqueri

Filho

Moura

et al. 2020

Macromolecular Symposia

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Cement is a material widely used in civil construction due to its physical and chemical properties, ensuring a good performance. Some polymeric materials, such as hydrogels, have been frequently added to improve these properties and mitigate autogenous retraction in cementitious matrices. This paper aimed to evaluate the influence of polymeric hydrogel on the fresh and hardened properties of cementitious pastes (water/binder ratio = 0.35). Fresh properties results showed that the consistency and exudation indexes of these matrices decreased with an increase in the amount of hydrogel. The values of the bulk density of all cementitious matrices are around 2.1–2.2 g cm−3. Matrices containing up to 1.0% of hydrogel have satisfactory mechanical properties, reaching compressive strength of 60 MPa for 112 days of curing age. From these results, it is possible to conclude that hydrogels are promising materials for civil engineering applications, acting mainly as a filler and hydroretentor agent.

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Performance of cementitious mortars containing hydrogel–nanoclay hybrid nanocomposite

Filho,

de Moura,

Aouada

2024

J Sol-Gel Sci Technol

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Cement-based composites comprise a binder matrix with or without aggregates. Hydration of cement is an exothermic reaction that releases considerable quantities of heat, causes drying shrinkage, and results in cracks that can compromise the performance of the structure. Hydrogels can help mitigate such cracking as their hydrophilic characteristics and 3D crosslinked structure enable them to absorb and directly release water into the cement matrix over time. The aim of this study is to synthesize and analyze the effect of adding hybrid nanocomposite hydrogels with different concentrations (0, 10, and 20% w/v) of Cloisite-Na + nanoclay in their fresh and hardened cement mortar states. The hydrogels were synthesized via free radical polymerization, and four cementitious mortar samples (M, M0, M10, and M20), were prepared with 1:2.16, 0.40 water/cement and 0.50% presoaked hydrogel (wt./wt cement ) ratios.The results demonstrated that the density of all the mortars in the fresh state was ~ 2.16 ± 0.01 g.cm − 3 , but a decreasing trend was observed that could attributed to the increase of air incorporation into the mortar. At 28 days, the results indicated that the hydrogel with 20% Cloisite-Na + was the most e cient, causing a reduction of ~ 4.41% in water absorption by the mortar. For all the three curing conditions considered, all mortars demonstrated considerable shrinkage over time. However, the controlled curing indicated that M20 mortars demonstrated 30.5% less shrinkage compared to the control sample. Thus, the results indicate that the mortars containing hydrogel demonstrate satisfactory behavior in both the fresh and hardened state, highlighting its e ciency as a curing agent.

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Obtainment of Hybrid Composites Based on Hydrogel and Portland Cement

Cited by 6 publications

References 0 publications

Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars

Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars

Effect of Hydrogel Nanocomposites on the Fresh and Hardened Properties of Cementitious Pastes

Performance of cementitious mortars containing hydrogel–nanoclay hybrid nanocomposite

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