The influence of water-repellent admixtures on the behaviour and the effectiveness of Portland limestone cement mortars

Falchi, Laura; Zendri, Elisabetta; Müller, Urs; Fontana, Patrick

doi:10.1016/j.cemconcomp.2015.02.004

Cited by 68 publications

(23 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, the HSila/Sil and HSil treatments decrease the DI on mortar specimens, with a lower decrease of the latter after artificial aging compared with the HNST treatment. As reported in other works [46], the silane/siloxanes products can modify the pore netwok of the treated material by increasing the volume of capillary pores, probably also due to an air entraining effect of liquid siloxane. This feature can justify the improved resistance to freeze-thaw cycles, and thus, durability of HSila/Sil and HSil The different moisture transport properties of mortar and limestone can be attributed to the higher open porosity (30%) of the mortar when compared to the studied limestone (11%).…”

Section: Discussionsupporting

confidence: 69%

Effect of Hygrothermal Aging on Hydrophobic Treatments Applied to Building Exterior Claddings

et al. 2020

View full text Add to dashboard Cite

Hydrophobic materials are among the most commonly used coatings for building exterior cladding. In fact, these products are easily applied to an existing surface, significantly reduce water absorption and have a minimal impact on the aesthetic properties. On the other hand, although these products have a proven effectiveness, their long-term durability to weathering has not yet been systematically studied and completely understood. For these reasons, this study aims to correlate the effect of artificial aging on the moisture transport properties of hydrophobic treatments when applied on building exterior claddings. Three hydrophobic products (an SiO 2 -TiO 2 nanostructured dispersion; a silane/oligomeric siloxane; and a siloxane) were applied on samples of limestone and of a cement-based mortar. The moisture transport properties (water absorption, drying, water vapor permeability) of untreated and treated specimens were characterized. Furthermore, the long-term durability of the specimens was evaluated by artificial aging, that is, hygrothermal cycles (freeze-thaw and hot-cold). All treatments have significant hydrophobic effectiveness and improve the long term-durability of the treated specimens. However, the results showed that the three hydrophobic products have different effectiveness and durability, with the SiO 2 -TiO 2 nanostructured dispersion being the most durable treatment on limestone, and the siloxane the most suitable for cementitious mortar.

show abstract

Section: Discussionsupporting

confidence: 69%

Effect of Hygrothermal Aging on Hydrophobic Treatments Applied to Building Exterior Claddings

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Currently, only the organosilicon compounds are used for hydrophobisation concrete with Portland cement. However, the disadvantage of this hydrophobic cement is that it is very expensive [21,25,26].…”

Section: Introductionmentioning

confidence: 99%

“…In many cases the admixture caused damage, e.g., greater decay of samples in the frost resistance test. Some admixtures are effective, but their selection must be confirmed by further research [20,21].…”

Section: Introductionmentioning

confidence: 99%

Hydrophobic Calcium Carbonate for Cement Surface

et al. 2017

View full text Add to dashboard Cite

This report describes a novel way to generate a highly effective hydrophobic cement surface via a carbonation route using sodium stearate. Carbonation reaction was carried out at different temperatures to investigate the hydrophobicity and morphology of the calcium carbonate formed with this process. With increasing temperatures, the particles changed from irregular shapes to more uniform rod-like structures and then aggregated to form a plate-like formation. The contact angle against water was found to increase with increasing temperature; after 90 • C there was no further increase. The maximum contact angle of 129 • was obtained at the temperature of 60 • C. It was also found that carbonation increased the micro hardness of the cement material. The micro hardness was found to be dependent on the morphology of the CaCO 3 particles. The rod like structures which caused increased mineral filler produced a material with enhanced strength. The 13 C cross polarization magic-angle spinning NMR spectra gave plausible explanation of the interaction of organic-inorganic moieties.

show abstract

“…A second, more effective class of admixtures, is based on water‐repellent hydrophobic compounds, normally consisting of fatty acids that inhibit wetting by increasing the wetting angle of liquid water . Such compounds are capable of providing decent waterproofing, but at the same time may alter both the rheological and mechanical properties . It has also been shown that the addition of nano‐SiO 2 and nano‐TiO 2 may enhance concrete permeability.…”

Section: Introductionmentioning

confidence: 99%

“…11 Such compounds are capable of providing decent waterproofing, but at the same time may alter both the rheological and mechanical properties. 12,13 It has also been shown that the addition of nano-SiO 2 and nano-TiO 2 may enhance concrete permeability. [14][15][16] In this study, we investigate the potential of a novel PCE/C-S-H nanocomposite admixture to act as a water permeability reducing agent.…”

Section: Introductionmentioning

confidence: 99%

Use of nanocomposites as permeability reducing admixtures

Valentini

Ferrari²,

Russo³

et al. 2018

J Am Ceram Soc

View full text Add to dashboard Cite

Permeability is one of the fundamental properties of concrete structures as it is strictly related to durability. Mitigation of the degradation processes induced by aggressive solutions can be achieved by controlling water penetration through the pore network. In this study, we test the potential use of nanocomposites as waterproofing agents in concrete. Macroscopic measurements show that the addition of a small amount of nanoparticles effectively reduces the extent of the water permeation front. A combination of experiments, based on X‐ray tomography, mercury intrusion porosimetry, and BET nitrogen adsorption, and of numerical simulations, are used to interpret the macroscopic observations. These investigations show that C–S–H precipitation away from cement surfaces, induced by the presence of nanoparticles, leads to a refinement of the pore network. Such a microstructural change in the cement matrix results in a net reduction in the overall concrete permeability.

show abstract

The influence of water-repellent admixtures on the behaviour and the effectiveness of Portland limestone cement mortars

Cited by 68 publications

References 26 publications

Effect of Hygrothermal Aging on Hydrophobic Treatments Applied to Building Exterior Claddings

Effect of Hygrothermal Aging on Hydrophobic Treatments Applied to Building Exterior Claddings

Hydrophobic Calcium Carbonate for Cement Surface

Use of nanocomposites as permeability reducing admixtures

Contact Info

Product

Resources

About