Utilization of fly ash cenosphere to study mechanical and thermal properties of lightweight concrete

Beddu, Salmia; Ahmad, Megat Mohamad Hamdan Megat; Mohamad, Daud; Ameen, Muhamed Imran bin Noorul; Itam, Zarina; Kamal, Nur Liyana Mohd; Basri, N. A. N.

doi:10.3934/matersci.2020.6.911

Cited by 20 publications

(13 citation statements)

References 22 publications

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“…In numerous previous works a negative effect on the early strength, e.g., [35][36][37][38][39][40][41] and physical properties, e.g., [42][43][44][45] gain of concrete composites with FA was described. This unfavorable characteristic of this waste unfortunately limits its application in certain branches of the concrete industry [46].…”

Section: Introductionmentioning

confidence: 99%

Rheology of Cement Pastes with Siliceous Fly Ash and the CSH Nano-Admixture

Szóstak

Golewski

2021

Materials

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The use of fly ash in cement composites adversely affects its mechanical properties during the first days of mixture curing. Modern technology, in the form of an admixture containing the hydrated calcium silicates, allows to accelerate the hardening and binding process of concrete. In this paper, studies on the influence of the admixture on properties of concretes with the ordinary Portland cements (OPC) containing the addition of siliceous fly ash (FA) have been carried out. As part of the experimental research, the authors conducted a series of studies for cement pastes modified with the addition of FA and the CSH nano-admixture (NA). In order to compare the mixtures, the following tests of cement pastes were carried out: the compressive and flexural strength, heat of hydration, SEM and rheological shrinkage. The mechanical parameters were tested after 4, 8, 12 and 24 h. The hydration heat test and microstructure analysis were carried out during the first 24 h of the concrete curing. All tests were carried out on the standard samples. On the basis of the heat of hydration test, much higher hydration heat was found in mixtures modified with the NA. During the shrinkage test, a positive effect of the NA was observed—the shrinkage during the first 28 days of mixture curing was lower than in the reference samples. The application of the CSH nano-admixture to cement pastes with the addition of FA has brought positive effects. Apart from a significant increase in strength in the first 24 h of mixture curing, a reduction in the rheological shrinkage was observed. The admixture can be successfully used in the ash concretes, in which a higher early strength is required.

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Section: Introductionmentioning

confidence: 99%

Rheology of Cement Pastes with Siliceous Fly Ash and the CSH Nano-Admixture

Szóstak

Golewski

2021

Materials

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“…It is due to properties of cenosphere that have lower density as compared to water. Hence, lower density contributed to lower conductivity in concrete [7].…”

Section: Thermal Conductivitymentioning

confidence: 95%

Thermal Properties of Concrete Containing Cenosphere and Phase Change Materials

Beddu

Basri

Mohamad

et al. 2021

Lecture Notes in Civil Engineering

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“…Thanks to the proposed compositions of concrete and paste mixtures, it was possible to determine the NA’s influence on the properties of unmodified composites as well as mixtures in which some OPC content was substituted by FA. The FA content was assumed at the level of 20% because, as shown in previous studies, such a content of the modifier has a positive effect on numerous mechanical parameters and the structure of composites with an altered binder composition [ 75 , 76 , 77 , 78 , 79 , 80 ].…”

Section: Materials and Experimental Methodologymentioning

confidence: 99%

Application of the C-S-H Phase Nucleating Agents to Improve the Performance of Sustainable Concrete Composites Containing Fly Ash for Use in the Precast Concrete Industry

Golewski

Szóstak

2021

Materials

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Siliceous fly ash (FA) is the main additive to currently produced concretes. The utilization of this industrial waste carries an evident pro-ecological factor. In addition, such actions have a positive effect on the structure and mechanical parameters of mature concrete. Unfortunately, the problem of using FA as a Portland cement replacement is that it significantly reduces the performance of concretes in the early stages of their curing. This limits the possibility of using this type of concrete, e.g., in prefabrication, where it is required to obtain high-strength composites after short periods of curing. In order to minimize these negative effects, this research was undertaken to increase the early strength of concretes with FA through the application of a specifically formulated chemical nano-admixture (NA) in the form of seeds of the C-S-H phase. The NA was used to accelerate the strength growth in concretes. Therefore, this paper presents results of tests of modified concretes both with the addition of FA and with innovative NA. The analyses were carried out based on the results of the macroscopic and microstructural tests in five time periods, i.e., after 4, 8, 12, 24 and 72 h. The results of tests carried out with the use of NA clearly indicate the possibility of using FA in a wide range of management areas in sustainable concrete prefabrication.

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Utilization of fly ash cenosphere to study mechanical and thermal properties of lightweight concrete

Abstract: Acknowledgments are due to representatives of government ministries and agencies as well as many others from a variety of organizations, for their essential contributions to each chapter of this book. Many of these bodies are specifically cited within the relevant parts of this report.

Cited by 20 publications

References 22 publications

Rheology of Cement Pastes with Siliceous Fly Ash and the CSH Nano-Admixture

Rheology of Cement Pastes with Siliceous Fly Ash and the CSH Nano-Admixture

Thermal Properties of Concrete Containing Cenosphere and Phase Change Materials

Application of the C-S-H Phase Nucleating Agents to Improve the Performance of Sustainable Concrete Composites Containing Fly Ash for Use in the Precast Concrete Industry

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