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Freeze-thaw cycles used. Figure 2. Sketch of the slices for different tests obtained from a cylindrical specimen.
Source publication
This work relates the curing conditions of concrete with the damage caused by rapid freeze-thaw cycles (ASTM C 666). The “potential” durability of concrete after testing is also studied. In countries with a continental climate, the curing of concrete in summer is performed under high-temperature and low-humidity conditions, and during the winter th...
Contexts in source publication
Context 1
... the case of the tests after freeze-thaw cycles, four sam- ples were obtained and tested; these were extracted at different distances from the circumferential face of the specimen in the radial direction. Figure 2 shows a sketch of the specimen with the slices for the various tests. ...
Context 2
... oxygen permeability tests were conducted according to RILEM-TC 116-PCD (35) and CEMBUREAU (36) recommendations. Tests were performed with two cylindrical slides (φ 150 mm 50 mm in thickness) cut from the bottom and upper parts of the specimen (see Figure 2). The flow of oxygen through concrete slides was measured at steady state against the test pressure and the material saturation rate. ...
Context 3
... Figure 20 reveals that the existence or otherwise of the air-entraining admixture categorically separated the results into two groups: with no admixture the mean was lower than 1, indica- ting the existence of damage, and the confidence interval was wide (this denoted the possible secondary effect of other variables in this case). With the admixture, the mean was clearly higher than 1, with a narrow confidence interval, revea- ling a lack of damage and the non-intervention of other variables when the admixture was present. ...
Context 4
... In an analogous sense, according to Figure 22 better performance was observed in the 45-MPa concrete. This was also reflected in both the mean value found for the categorical group and the breadth of the confidence interval. ...
Context 5
... The durability characteristics of concrete expo- sed to freeze-thaw cycles are related to its pore microstructure. The pore volume, radius and Figure 20. Graph of error-bar at 95% confidence for concrete with and without air-entraining. ...
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Citations
... 20,50,62 Looking at the results after carbonation, a drop in the cumulative porosity can be observed in both fly ash and calcined clay mix, which is usually seen in OPC samples. 59 These results are in contrast with the research regarding ternary blends of calcined clay cements due to the low kaolinite content. 35 The reduction is visible in the microporosity-as seen in figure 6B, where peeks between 0.01-0.1 μm reduce significantly-as well as in the mezzo and macro porosity. ...
With the decrease in availability of common supplementary cementitious materials (SCMs) such as fly ash in Europe, the search for appropriate SCMs should be dealt with locally. A combination of abundant low-grade calcined clay and limestone powder has proven relatively inexpensive to produce while maintaining satisfying performance compared to existing cements. In this study, ternary cement mixtures containing 45 % ordinary portland cement and 55 % SCMs-limestone powder with either low-grade calcined clay or high-volume fly ash (HVFA), were compared in terms of freeze-thaw resistance, water permeability, carbonation, and compressive strength of concrete according to European standards. The main aim of the study was the evaluation of potential durability challenges of local limestone and calcined clay (LC 3) binder and the possibility of its utilization as an ecological alternative to HVFA blends fitted for general application. The results suggest a similar performance of both binders in terms of compressive strength, carbonation, and freezing and thawing resistance, though the water penetration resistance seems to increase with the LC 3 binder. The reduced water-permeable porosity of this binder, measured by mercury porosimetry, could influence the diffusivity of concrete, especially after carbonation.
... However, the researchers point out that it is necessary to be careful when conducting research on concretes that have a short production time. During freeze and thaw cycles, young concretes can complete hydration, which can lead to erroneous interpretation of the data obtained [11]. ...
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