cement concrete sem
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- cement concrete sem
Sample preparation and SEM imaging of cement samples4.1. Cement sample preparation and freeze–thaw tests. The cement paste samples were prepared by following the ASTM C305-06 standard. The w/c ratios of 0.47 and 0.45 were used. The cement paste samples were fabricated using a straw as a mold with an inner diameter of …
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Concrete Experts International offers services on scanning electron microscopy on concrete and related materials such as aggregates for concrete production, cement, metals and fibers. A scanning electron microscope equipped with energy dispersive X-ray analysis (SEM- EDX) is an important supplement to the optical microscope when …
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Download scientific diagram | SEM of CH and CSH, Mix 50 from publication: An investigation of nano silica in the cement hydration process | With the advent of nano technology, materials have been ...
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PDF | This research reports on the experimental study on Sustainable High Performance Concrete and its microstructural …
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Backscatter SEM image of an area around a sand grain in a well-mixed three-day-old w:c 0.50 concrete. An approximate boundary at 30 μm from the sand grain is superimposed on the figure. ... It has been established that such bad mixing produces concrete in which all of the cement paste has a high content of coarse pores [6]. To …
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The diffusion mechanisms of CO 2 gas in concrete were analysed through the scanning electron microscopy (SEM) observations. Experimental results showed that, under the same carbonation age, the increase of carbonation depth was found to be high when concrete samples were exposed to low CO 2 concentrations (i.e. 2–20%); and low …
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Fig. 5. Effect of dolomite limestone fine powder specific surface on cement concrete compression strength at 7 days age When limestone content is optimal (25 % of binder weight), strength gain is higher than in the reference sample (0% additives) by 56 %. ... SEM microstructure of concrete: (а) without dolomite limestone, 7 days age at à ...
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Pore structure characterization of hardened cement paste is important to concrete mechanical and transport properties. Hence, we apply indirect methods (NS, MIP, and NMR) and direct methods (XCT, …
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SEM images from crack walls after re-cracking. In addition, most of the investigations on self-healing were carried out in the laboratory, the in-situ studies are much far from satisfactory. ... oil well cement, concrete-filled steel tubes, etc. Table 4 summarizes some applications of MgO expansive cement. Although the light-burnt MEA ...
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This paper offers a brief review of the present use of scanning electron microscopy (SEM) in concrete studies, from the perspective of how research in …
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Microbial calcite-precipitation is used as a smart and eco-friendly approach to produce bio-based durable concrete. • SEM, EDAX & DTA verified that the addition of B. pasteurii & B. sphaericus into mortar induced calcite bio-precipitation.. Bacterial mortar had high restoration for load deflection & stiffer with less deformation than control, confirming …
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cement paste. 150 µm field width. Summary The application of scanning electron microscopy enhances our ability to characterize cement and concrete microstructure, and will aid in evaluating the influences of supplementary cementing materials, evaluating concrete durability problems, and in the prediction of service life. SEM and X-ray imaging
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Fig. 1, taken from [2] is one of the first secondary electron SEM images published, and shows the characteristic fibrous structures found in open porous areas on fracture surfaces of young Portland cement pastes. Practically identical images were subsequently published by many authors, including Diamond [1] and Scrivener [7].In Fig. …
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This section covers the scanning electron microscopy and image processing techniques used to obtain starting 2-D images of cement-based materials (cement powder, fly ash, etc.) dispersed in an epoxy resin. (4a) SEM/X-Ray Imaging of Cement-Based Materials (4b) SEM Analysis and Computer Modelling of Hydration of Portland Cement …
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Use of the scanning electron microscope (SEM) with X-ray microanalysis allows study of clinker and cements; permitting measuring bulk phase abundance and …
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Abstract. This paper offers a brief review of the present use of scanning electron microscopy (SEM) in concrete studies, from the perspective of how research in materials science is translated into applications in construction engineering. It describes the scope of present use of the method, and attempts a prospective for the near future in ...
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Fig. 2 shows the crystal of CH, the product of cement hydration and the reactants of pozzolanic reaction, which has a laminar morphology in (a) and supported by EDX analysis in (b) [1], [5].The fly ash particles in the concrete mix react slowly with CH to form C–S–H gels, and the process goes on for years [2], [6], [7], [8]. Fig. 3 shows the …
به خواندن ادامه دهیدCement is one of the essential constituents in the manufacture of concrete; the most widely used building material in the world. ... (C-S-H) phase measured by the SEM-EDS analysis on the hydrated cement paste at 2 days is also higher than the theoretical value of 1.7 used in the equations of cement hydration. This difference can be due to the ...
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1 day agoThe cement industry is setting ambitious targets to reduce emissions and transition to a low-carbon future. There are a number of promising new technologies, …
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Due to the small dimensions of interfacial transition zone (ITZ) in concrete, the measurement of ITZ is subjected to difficulties of deformation measuring at macro-scale and loading at micro-scale. This work presents a coupled strategy between the scanning electron microscope (SEM) technology and the digital image correlation (DIC) method to …
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The surface microstructure of the cement is investigated by SEM, EDX, and micro-Raman after embedding in geopolymer or immersion in the activation solution of a geopolymer for various durations. It is found that immersion …
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2.1 Control Concrete (CC). Control concrete of M40 grade was designed to achieve a 28-day compressive strength of 40 MPa at a water–cement ratio of 0.43. The CC mix included 400 kg/m 3 of cement, 735 kg/m 3 of river sand and total water content of 172 kg/m 3.The coarse aggregate of size varying from 20 to 12 mm was used and the total …
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Waste-rubberized ceramsite concrete is an improvised building material that is suitable for lightweight wall panels, which can significantly reduce the bulk density of buildings. In this study, the effects of different water–cement ratios on the mechanical properties, water absorption, ultrasonic velocity, and sulfate corrosion resistance of …
به خواندن ادامه دهیدMaterials, like geopolymer concrete, zero-waste, and circular economy paradigm, can be used to safeguard finite natural resources, lower CO2 emissions, and manage climate change. It completely replaces Portland cement with waste industrial products such as slag, metakaolin, silica fume, coal ash, and fly ash which is available; it …
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Two cement paste samples with different water-to-cement (W/C) ratios are cured for five curing durations. Multiple SEM images of the samples are taken, cropped, and labeled to generate a dataset for training and validation of a deep learning model. Thereafter, the trained model is used to segment unhydrated regions.
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On the one hand, the increase in the carbonation products leads to expansion stress in the small pores. When the cement and concrete materials are subjected to an external tensile stress, the expansion stress intensifies and damages the cement concrete structure [24]. The above SEM results also show that under the …
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Studies of cement concrete microstructure were facilitated by the use of a scanning electron microscope (SEM). Imaging of polished sections provides high-magnification, high resolution (less than ...
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Indeed, cement hydration is a 3-dimensional process, and the SEM images captures information on a cross section of the samples. Nevertheless, the hydration degree was calculated based on volume fraction of the cement particles, which can be obtained by measuring the area fraction on a polished plane section and this is a classical application ...
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Abstract. Scanning electron microscopy (SEM) is a widely used method for the analysis of concrete micro structure. To quantitatively analyze the SEM images with …
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The characterisation of cement paste microstructure is an important step towards understanding durability mechanisms in cementitious materials. Scanning …
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