Experimental study and modelling of heat evolution of blended cements

Paine, Kevin; Li, Zheng; Dhir, Ravindra K.

doi:10.1680/adcr.2005.17.3.121

Cited by 21 publications

(14 citation statements)

References 10 publications

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“…The Table shows that the total heat generated increased with increasing test age. At the test ages, in line with Thomas et al [5] and Paine et al [7], the heat of hydration of fly ash binary cements were lower than that of ordinary Portland cement and they were reduced with increasing content of fly ash. This is probably due to the dilution effect as a result of reduction in the Portland cement content and amount of Ca(OH)2 available for pozzolanic reaction.…”

Section: Heat Of Hydration Of Cementsupporting

confidence: 78%

“…Fly ash, due to its availability, is a primary supplementary cementitious material in concrete [3,4]. However, while it is characterised by low water demand and improved workability [5,6], its use would reduce the heat of hydration [5,7], retard the hydration reaction [8], and reduce the early-age performance of concrete [9,10]. Comparatively, the fineness of silica fume and metakaolin would increase the heat of hydration [11,12], accelerate the hydration reaction [13] and enhance the strength development [5,[14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

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Early-age Performance of Cement Combination Concrete

Folagbade

2017

ced

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Heat of hydration up to 72 hours and compressive strength up to 7 days of Portland cement and 17 binary and ternary cements containing fly ash, silica fume, and metakaolin, at a water/cement ratio of 0.50 and addition contents of 20%, 35%, and 55%, were used to examine the early-age performance of concrete. Results revealed that early-age performance depends on the fineness, heat of hydration, and dilution effect of cement combinations. Fly ash, due to dilution effect, reduces the heat of hydration and compressive strength. Using silica fume and metakaolin with increasing content of up to 10% as binary and ternary cement components, due to their fineness and increased heat of hydration, supports the strength development. Most of the cement combinations met the standard of strength requirements for ordinary early-age performance of concrete, while only half of it satisfied the standard for high early-age performance.

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Section: Heat Of Hydration Of Cementsupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Early-age Performance of Cement Combination Concrete

Folagbade

2017

ced

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“…The slag particles can serve as nucleic sites for the cement particles, leading to the chemical activation of cement hydration. In fact, as proposed by Paine et al [28], in the hydration process of cement-slag blends, the influences of delay and acceleration effects on heat evolution are not significant and, for practical purposes, can be ignored. Therefore, the physical effects were not considered in this paper, but will be addressed in future research.…”

Section: The Simulation Of the Slag Reaction In Cement-slag Blendsmentioning

confidence: 99%

A multi-phase kinetic model to simulate hydration of slag–cement blends

Wang¹,

Lee²,

Park³

et al. 2010

Cement and Concrete Composites

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“…The fly ash or silica fume particles can serve as nucleation sites for the cement particles and promote chemical activation of the hydration process. In the case of cement-slag blends, as proposed by Paine et al (2005), the influences of delay and acceleration effects on the heat evolution of cement are not significant and for practical purposes can be ignored. In this paper, the physical effect of the addition of fly ash on cement hydration is considered through the coefficient B 20 , which is related to the initial dormant period of cement hydration and is adjusted to fit the experimental results of the temperature rise history, while all other coefficients are not changed.…”

Section: Water Withdrawal Mechanismmentioning

confidence: 99%

Heat of hydration models of cementitious materials

Wang

Lee

2012

Advances in Cement Research

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Silica fume from certain metallurgical operations, granulated slag from metal industries and fly ash from the combustion of coal are industrial by-products that have been widely used as mineral admixtures in normal-and highstrength concrete. Due to the reaction between calcium hydroxide (CH) and mineral admixtures, the hydration of concrete containing mineral admixtures is much more complex compared with that of Portland cement. In this paper, the production of CH in cement hydration and its consumption due to the reaction of mineral admixtures is considered in order to develop a numerical model that simulates the hydration of concrete containing silica fume, fly ash or slag. The heat evolution rates of these admixture-blended concrete were determined by the contribution of both cement hydration and the reaction of the mineral admixtures. The proposed model was verified with experimental data on concrete with different water/cement ratios and mineral admixture substitution ratios. IntroductionMineral admixtures (fly ash, silica fume and slag) are usually added to concrete to enhance the workability of fresh concrete, to improve resistance to thermal cracking, alkali-aggregate expansion and sulfate attack, and to enable a reduction in cement content. The utilisation of by-product mineral admixtures not only improves concrete properties but also reduces concrete cost and environmental problems (Mehta and Monteiro, 2006;Taylor, 1997).In hardening massive concrete elements, the heat of hydration gives rise to considerable thermal gradients and thermal stresses, which may cause early-age cracking. A cogent simulation of an exothermic hydration process in cement plays a crucial role in quantifying thermal stress and assessing the risk of thermal cracking in mass concrete. Tomosawa et al. (1997) proposed a hydration model to estimate the heat liberation rate during the hydration of Portland cement and the adiabatic temperature rise in concrete. In this model, the residual concentration of water is used as a parameter indicating the decline of the reaction rate towards the reaction end point. The influence of temperature on cement hydration is considered by the Arrhenius law. Based on Tomosawa's model, Park and co-workers (Park, 2001;Park et al., 2008) constructed a microstructural hydration model of Portland cement that considers the reduction in the hydration rate that occurs due to the reduction of free water and the reduction of the interfacial area of contact between the free water and the hydration products. Based on a hydration model using a finiteelement method, the temperature distribution of high-strength concrete was evaluated. Swaddiwudhipong et al. (2002) proposed a multi-constituent model of Portland cement hydration by combining the multi-component model of Kishi and Maekawa (1996) with the hydration model of Parrot and Killoh (1984). The concept of equivalent maturity is introduced explicitly to reflect the influence of temperature on the rate of hydration heat release.Compared with Portland cement, the h...

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Experimental study and modelling of heat evolution of blended cements

Cited by 21 publications

References 10 publications

Early-age Performance of Cement Combination Concrete

Early-age Performance of Cement Combination Concrete

A multi-phase kinetic model to simulate hydration of slag–cement blends

Heat of hydration models of cementitious materials

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