Influence of colloidal silica sol on fresh properties of cement paste as compared to nano-silica powder with agglomerates in micron-scale

Kong, Deyu; Corr, David J.; Hou, Pengkun; Yang, Yang; Shah, Surendra P.

doi:10.1016/j.cemconcomp.2015.08.002

Cited by 138 publications

(64 citation statements)

References 45 publications

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“…However, these traditional accelerators also have many undesired drawbacks such as the promotion of steel corrosion, adverse effect on final strength etc . In recent years, it was found that many nanoparticles, including nano‐SiO 2 , nano‐TiO 2 , nano‐CaCO 3 , nano‐C‐S‐H exhibit remarkable acceleration effect on cement hydration due to the nucleation effect . It has been well understood that cement hydration involves mainly dissolution of clinker phases and precipitation of hydration products such as AFt, C‐S‐H, and CH .…”

Section: Introductionmentioning

confidence: 99%

The effects of nano‐C‐S‐H with different polymer stabilizers on early cement hydration

et al. 2019

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A promising approach to accelerate cement hydration known as “seeding technology” has been discovered using nano‐particles to provide additional nucleation sites for growing of C‐S‐H. Two different types of polymer, polycarboxylate (PCE) and polysulfonate (PSE) were used as stabilizer to synthesize nano‐C‐S‐H via co‐precipitation process. The obtained C‐S‐H‐polymer composites were characterized by means of XRD, FTIR, thermogravimetric analysis (TGA), TEM, dynamic laser scattering (DLS), and BET. DLS measurement shows that the particle size of the obtained C‐S‐H‐polymer suspension ranges from 82.6 to 589.9 nm. The results of DLS and BET show that the particle size of the C‐S‐H particles synthesized using PCE polymer as stabilizer is smaller than those synthesized with PSE polymer, and hence the specific surface area is much higher. FTIR and TGA results confirm the presence of the polymers in the obtained C‐S‐H composites particles. XRD results indicate that the presence of the polymers reduces the crystallinity of C‐S‐H due to the absence of the d002 peak at 2θ of 7°. The calorimetry results show that the main hydration peak of cement is dramatically increased by the addition of the C‐S‐H‐polymer composites. It is interestingly found that the acceleration effect of the C‐S‐H‐polymer composites is linearly proportional to the total surface area of the nanoparticles introduced into the cement pastes. At the same time, it is found that the secondary hydration peak, usually known as the sulfate‐depletion peak, is greatly advanced by addition of the C‐S‐H nano‐particles in comparison with the blank cement paste. The acceleration effect of the nano‐C‐S‐H is further verified in a pure C3S system.

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Section: Introductionmentioning

confidence: 99%

The effects of nano‐C‐S‐H with different polymer stabilizers on early cement hydration

et al. 2019

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“…Generally, cement hydration products always have irregular shapes and randomly agglomerate, resulting in the formation of disordered microstructures [12,13,14]. The main solution for reducing the cracks of a cement matrix still mainly depends on filling various fibers and nano mineral materials [15,16,17]. These fibers and materials cannot control the shape and aggregate state of cement hydration products; the irregular agglomeration of the cement hydration crystals with an irregular shape inevitably produces many cracks and holes in the cement matrix.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Cement Composites with Ordered Microstructures via Doping with Graphene Oxide Nanosheets and an Investigation of Their Strength and Durability

Zhang

Zhu

et al. 2016

Materials

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The main problem with cement composites is that they have structural defects, including cracks, holes, and a disordered morphology, which significantly affects their strength and durability. Therefore, the construction of cement composites with defect-free structures and high strength and long durability is an important research topic. Here, by controlling the size and chemical groups of graphene oxide nanosheets (GONs) used for doping, we were able to control the entire cement matrix to form an ordered microstructure consisting of polyhedron-like crystals and exhibit flower-like patterns. The cracks and holes in the cement matrix just about vanished. The compressive and flexural strengths as well as the parameters for the durability assessment of the corresponding cement composites obviously improved compared with the control samples. Thus, the formation mechanism of the cement matrix with the ordered microstructure is proposed, and a proper explanation is given to regulation action.

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“…Addition of colloidal silica sol with mono-dispersed nano-particles has shown a more significant accelerating effect on cement hydration than that of powered nano-silica [30]. As result of the accelerating effect on cement hydration, most of compressive strength gain of cement pastes containing nano-silica is attained within the first 7 days [13].…”

Section: Introductionmentioning

confidence: 93%

“…Besides the pozzolanic activity of nano-silica, these particles can also act as nucleation sites due to their high specific surface area accelerating the hydration of the cement paste [23,[25][26][27][28][29][30]. Nano-silica reacts quickly with the calcium hydroxide released during cement hydration generating mineral compounds similar to CSH gel produced by cement.…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties and microstructure of high performance concrete containing stabilized nano-silica

et al. 2017

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Nanotechnology can significantly improve the mechanical strength and durability of concrete. At the nanoscale, good dispersion of constituent materials is an essential factor for the improvement of concrete properties. In this scenario, the objective of this research was to evaluate the mechanical properties of high performance concrete containing stabilized nano-silica. The incorporation of nano-silica to the polycarboxylate chemical admixture allowed its application in concrete, since the nano-silica was evenly dispersed in the concrete mass. For this study, three different concretes were employed: a reference concrete, one containing stabilized nano-silica and another containing a mixture of silica fume and stabilized nanosilica. The evaluated concrete mechanical properties were the axial compressive strength and secant modulus of elasticity measured in three different ages. The results indicated a substantial increase in concrete compressive strength and modulus of elasticity with the addition of stabilized nano-silica combined with a reduction in cement content. The results also showed that use of stabilized nano-silica proved to be very advantageous, especially when mixed with silica fume. When they were combined, a synergy effect occurred in the concrete that was of chemical nature in addition to the physical effect of better concrete particle packaging. Analysis by scanning electron microscopy showed the improvement in microstructure of concretes with stabilized nano-silica, which contributed to gains in mechanical properties.

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Influence of colloidal silica sol on fresh properties of cement paste as compared to nano-silica powder with agglomerates in micron-scale

Cited by 138 publications

References 45 publications

The effects of nano‐C‐S‐H with different polymer stabilizers on early cement hydration

The effects of nano‐C‐S‐H with different polymer stabilizers on early cement hydration

Preparation of Cement Composites with Ordered Microstructures via Doping with Graphene Oxide Nanosheets and an Investigation of Their Strength and Durability

Mechanical properties and microstructure of high performance concrete containing stabilized nano-silica

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