Role of cement content in specifications for concrete durability: cement type influences

Dhir, R. K.; McCarthy, M. J.; Zhou, S.; Tittle, P. A. J.

doi:10.1680/stbu.157.2.113.36479

Cited by 8 publications

(14 citation statements)

References 7 publications

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“…The carbonation resistance of these lime-pozzolan concretes is lower than that of the CEMI-based concretes investigated by Dhir et al (2001) [29]. By extrapolation of tests results presented by Dhir, a comparable CEMI concrete (with a carboniferous limestone aggregate and a water content of 240kg/m 3 ) at a w/b 0.65, might be expected to carbonate around 20mm in 20 weeks at 4% CO 2 exposure (where 1 week ≈ 1 years natural exposure).…”

Section: Figure 5: Measured Carbonation Resistancementioning

confidence: 70%

“…The relative humidity of the chamber was maintained around 60% using a tray of saturated sodium bromide solution [27]. When analysing the results it was conservatively assumed that 1 week in the carbonation chamber was equivalent to 1 year of exposure to the atmosphere, in line with the work of others [28] & [29]. At 14 day intervals a 50 mm slice of the specimen was sampled using a bolster and chisel.…”

Section: Accelerated Carbonationmentioning

confidence: 99%

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Structural and durability properties of hydraulic lime–pozzolan concretes

Grist

Paine

Heath

et al. 2015

Cement and Concrete Composites

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Section: Figure 5: Measured Carbonation Resistancementioning

confidence: 70%

Section: Accelerated Carbonationmentioning

confidence: 99%

Structural and durability properties of hydraulic lime–pozzolan concretes

Grist

Paine

Heath

et al. 2015

Cement and Concrete Composites

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“…At the same time there are two influences: cement quantity and w/c ratio. Based on the findings of Dhir et al (2004Dhir et al ( , 2006 it can be concluded that the influence of higher cement quantity on strength reduction for HSCs with low w/c ratios is relatively small. Thus, in the case of concretes H-2 and H-3 the compressive strength of the first concrete is larger than that of the second owing to the dominating influence of the w/c ratio.…”

Section: Resultsmentioning

confidence: 96%

“…Since, over a given period of time, more cement means more hydration products, as long as sufficient water is available, the early strength of the concrete containing more cement will be greater than that containing less cement. On the other hand, Dhir et al (2004Dhir et al ( , 2006 found that 28 day compressive strength of concrete at a given w/c ratio drops by increasing the cement quantity. They distinguished concretes with w/c ratios of 0 .…”

Section: Resultsmentioning

confidence: 99%

“…Several parameters, among which the most important are the type and quantity of cement, the w/c ratio (water/(Portland cement + addition) ratio) (Aïtcin, 1998) and curing temperature of hardening concrete (Abdel-Jawad, 2006), affect the process of hydration and the quantity of heat released. However, the elements with the greatest influence on the engineering properties of concrete are the w/c ratio, the cement type and the coarse aggregate type, with cement content generally being a second-order effect (Dhir et al, 2004(Dhir et al, , 2006.…”

Section: Introductionmentioning

confidence: 99%

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The effect of constituent materials on the time development of the compressive strength of high-strength concrete

Saje

Lopatič

2010

Magazine of Concrete Research

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The effect of the constituent materials of different types of high-strength concretes, and the other characteristics of concrete mix, on the development of compressive strength has been studied. The measured values of the compressive strengths of concretes made using different types of cement and types of aggregate, as well as w/c ratios (water/ (Portland cement + addition) ratios) and amounts of silica fume, have been compared and analysed. This investigation was performed with the emphasis on the early stages of maturing of such concretes. The results of measurements of compressive strength are shown from the initiation of the hardening process up to an age of 360 days. In the case of concretes containing cement with a high specific surface area and a predominant amount of alite, as well as in the case of concretes containing no silica fume or only a small amount of it, compressive strength increased rapidly in the early stage of hardening, whereas later its rate of increase was, in the majority of cases, practically insignificant. IntroductionIt is well known that, during the long duration of the hydration process, the compressive strength of concrete changes. An adequate knowledge of the time development of both mechanical and rheological properties of concretes is therefore indispensable in designing, as well as constructing, concrete structures. Models used to anticipate compressive strength are typically developed on the basis of experimental research, thorough analysis of the obtained results and constitute as such a base for designing and predicting the behaviour of structures. Adequate understanding of the compressive strength development of a concrete during its early stage will help in accelerating the construction process, determining the safe time for form stripping and for post-tensioning of prestressed concrete or the proper time to conduct any construction activity.The hydration of cement, which is attributable to the exothermic chemical reaction of cement with water, results in the formation of hydrated cement paste, which is the most essential element contributing to the strength of concrete. Several parameters, among which the most important are the type and quantity of cement, the w/c ratio (water/(Portland cement + addition) ratio) (Aïtcin, 1998) and curing temperature of hardening concrete (Abdel-Jawad, 2006), affect the process of hydration and the quantity of heat released. However, the elements with the greatest influence on the engineering properties of concrete are the w/c ratio, the cement type and the coarse aggregate type, with cement content generally being a second-order effect (Dhir et al.

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Genetic prediction of cement mortar mechanical properties with different cement strength class after freezing and thawing cycles

Ghaemi‐Fard

Eskandari‐Naddaf

Ebrahimi

2018

Structural Concrete

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This study predicts the mechanical properties of cement mortars. It focuses specifically on cement strength classes of 32.5, 42.5, and 52.5 MPa, respectively. To this end, a total of 270 specimens using 54 mix designs were constructed and subjected to freezing and thawing cycles (FTCs) at −18 and 18 °C. Then, mechanical properties such as compressive and flexural strength and porosity of the specimens after 0, 50, 100, 150, and 200 cycles were obtained. Afterward, genetic expression programming (GEP) was used to predict the obtained results and to represent nonlinear relationships between the mechanical properties, freezing and thawing cycle, and cement strength class. The experimental data was used for training and testing of two GEP approach models. The results show that the strength of mortar reduces with increase in FTC. On other hand, a close correlation was observed between the predicted and experimental values when cement strength class and number of cycle were considered as independent input parameters. This fact indicates the significance of the aforementioned parameters along with the other parameters such as water to cement ratio, sand to cement ratio, and weight of cement on the accuracy of the prediction.

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Role of cement content in specifications for concrete durability: cement type influences

Cited by 8 publications

References 7 publications

Structural and durability properties of hydraulic lime–pozzolan concretes

Structural and durability properties of hydraulic lime–pozzolan concretes

The effect of constituent materials on the time development of the compressive strength of high-strength concrete

Genetic prediction of cement mortar mechanical properties with different cement strength class after freezing and thawing cycles

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