Abstract:Abstract:Recently, modern techniques have been applied for analysis of the influence of polymers on microstructural properties of Portland cement, such as Thermogravimetric Analyses (TG), Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Mercury Intrusion Porosimetry (MIP). In this study, thermogravimetric analyses were used to study the influence of vinyl acetate-versatic vinylester copolymer (VA/VeoVA) in seven pastes of 28-day old Portland cement, in which distinct po… Show more
“…During the hydration, hydrophilic part of the polymer was oriented towards the water phase whereas the hydrophobic part headed towards the air phase (pores and capillaries that were not filled with water). Upon drying which was on day 28, as the water taken away, the hydrophobic particles coalesced together to form film and block the pores hence the later occurrence of pore blocking effect [2,5]. On the other hand SAE copolymer is a reactive polymer where ester linkage can form crosslink with Ca 2+ ion preventing Ca(OH) 2 from leaching [2].…”
Section: Resultsmentioning
confidence: 99%
“…All samples were drycured in the concrete laboratory with average temperature (T) of 32ºC and relative humidity (RH) of 90%. [5,6].The water in the circle could vaporized or absorbed by the samples. On specified day, the surface of the samples was scraped to extract powder of 1 gram in weight.…”
Section: Methodsmentioning
confidence: 99%
“…The polymer spheres are small and can therefore block pores and capillaries and subsequently prevent water loss by reducing shrinkage. The plastic coating on the surface has a much greater resistance to the variety of chemical attack compared to the conventional mortar [1,[3][4][5]. A similar mechanism to shrinkage cases, capillary pores are blocked and thus reducing permeability that might cause the efflorescence phenomenon.…”
The early hydration behaviour of two different polymer composites cement systems (PCCS) that hypothetically affects efflorescence has been investigated through physicochemical characterization namely Puddle Test (PT), Standard Chemical Method (SCM), Compressive Strength Test (CS), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). PCCS mortar samples were prepared with water-to-cement ratio (w/c) of 0.50. Commercially available polymer additives namely Styrene Butadiene Rubber (SBR) and Styrene Acrylic Ester (SAE) with different percentages of addition of 5%, 7% and 10% to cement were used. All samples were dried cured and tested at day 28. Efflorescence was accelerated by using PT. Its intensity, in terms of the amount of Calcium Carbonate (CaCO 3 ) precipitated on samples' surfaces, was quantified by using SEM. Results of the PCCS were then compared to the conventional cement system. Based on this study, PCCS can potentially reduce efflorescence where validation from CS, XRD analysis and SEM images showed that the evidence of the pore blocking effects of PCCS in early hydration hence can indirectly improve concrete durability and sustainability.
“…During the hydration, hydrophilic part of the polymer was oriented towards the water phase whereas the hydrophobic part headed towards the air phase (pores and capillaries that were not filled with water). Upon drying which was on day 28, as the water taken away, the hydrophobic particles coalesced together to form film and block the pores hence the later occurrence of pore blocking effect [2,5]. On the other hand SAE copolymer is a reactive polymer where ester linkage can form crosslink with Ca 2+ ion preventing Ca(OH) 2 from leaching [2].…”
Section: Resultsmentioning
confidence: 99%
“…All samples were drycured in the concrete laboratory with average temperature (T) of 32ºC and relative humidity (RH) of 90%. [5,6].The water in the circle could vaporized or absorbed by the samples. On specified day, the surface of the samples was scraped to extract powder of 1 gram in weight.…”
Section: Methodsmentioning
confidence: 99%
“…The polymer spheres are small and can therefore block pores and capillaries and subsequently prevent water loss by reducing shrinkage. The plastic coating on the surface has a much greater resistance to the variety of chemical attack compared to the conventional mortar [1,[3][4][5]. A similar mechanism to shrinkage cases, capillary pores are blocked and thus reducing permeability that might cause the efflorescence phenomenon.…”
The early hydration behaviour of two different polymer composites cement systems (PCCS) that hypothetically affects efflorescence has been investigated through physicochemical characterization namely Puddle Test (PT), Standard Chemical Method (SCM), Compressive Strength Test (CS), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). PCCS mortar samples were prepared with water-to-cement ratio (w/c) of 0.50. Commercially available polymer additives namely Styrene Butadiene Rubber (SBR) and Styrene Acrylic Ester (SAE) with different percentages of addition of 5%, 7% and 10% to cement were used. All samples were dried cured and tested at day 28. Efflorescence was accelerated by using PT. Its intensity, in terms of the amount of Calcium Carbonate (CaCO 3 ) precipitated on samples' surfaces, was quantified by using SEM. Results of the PCCS were then compared to the conventional cement system. Based on this study, PCCS can potentially reduce efflorescence where validation from CS, XRD analysis and SEM images showed that the evidence of the pore blocking effects of PCCS in early hydration hence can indirectly improve concrete durability and sustainability.
“…Bands near 1420, 870, and 710 cm −1 may be attributed to the presence of carbonate phase while the shoulder near 1116 cm −1 is related to the sulphate phase. On the other hand, band near 920 cm −1 may refer to anhydrous calcium silicate (Figure 2(b)) [12,13]. It should be stated that an identical spectrogram is identified in the cement-waste form (Figure 2(c)).…”
The current work was devoted to study the solidification of bioproducts originated from the bioremediation of mixture of solid cellulose-based radioactive waste simulates using a mushroom (Pleurotus pulmonarius), in Portland cement. The obtained solidified waste form was subjected to mechanical integrity qualification after curing periods of 28 and 90 days. Chemical performance of the cement-waste form was also evaluated in different leachant media during 540 days. The results obtained gave useful information about the mechanical, physical, and chemical performances of the final cement-waste form incorporated the radioactive bioproducts. Moreover, it indicated that cement can provide a highly durable form that ensures a long-term stability of the solidified waste material and can act as a first barrier against the release of radiocontaminants from radioactive wastes to the surrounding environment.
“…The modification with redispersible polymer powders is similar to that of latex formation except that it also involves the redispersion of the polymer powders [8][9][10][11][12][13][14][15] . In these cases, the modification is governed by both Portland cement hydration and polymer film formation processes in their binder phase [16][17][18][19][20][21][22] .…”
Fiber cement, similarly to all cementitious materials, undergoes dimensional and volumetric changes when it is exposed to dry and wet environments. When exposed to natural weathering, cement-based materials absorbs and may also release water to their surroundings via a very complex inherent pore structure. In this work initialized a few years ago, some properties of asbestos-free fiber cement composites were studied, such as density, porosity and loss or absorption of water. For the understanding of the behavior of this material, modifiers were employed in the cement matrix such as styrene-acrylic, styrene-butadiene and vinyl acetate-versatic vinylester copolymers to verify their influence on the variables described above. All composites were analyzed by mercury intrusion porosimetry (MIP). For monitoring the expansion/shrinkage movements, the specimens were exposed inside a controlled environmental chamber with constant temperature and relative humidity (RH) during the test time. The results showed no interference on hygral behavior because particular casting process of these composites but, as showed by literature, increase of toughness. Also, it was possible to verify that moisture movement within the asbestos-free fiber cement can be very complex and the variables density and porosity (pore structure) play a very important role in the expansion/shrinkage properties of these composites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.