Temperature-dependent late hydration of calcium aluminate cement in a mix with calcite – Potential of G-factor quantification combined with GEMS-predicted phase content

This article presents the results of research on the wastes of sanitary ceramics as an aggregate to concretes. The case of high temperature load was taken into account. Six concrete mixes were designed on Portland and calcium aluminate cement with various content of aerating admixture. Only the ground waste ceramics were used as an aggregate from one of the Polish sanitary ceramics plants. The abrasion test by Boehme blade of the designed concrete was conducted within the frame of study and compression strength tests on the cylindrical samples were performed as well. Some samples were initially annealed at 400 or 800 °C prior to strength tests. In order to determine the impact of annealing on the phase content and the concrete sample structure, the analyses on phase content (XRD—X-ray diffraction) and scanning electron microscopy (SEM) were conducted. The tests on compression strength demonstrated that there is considerable resistance of concrete containing ceramic aggregate and calcium aluminate cement to high temperatures. Abrasion tests confirmed that selected mixes have a high resistance to abrasion and they can be applied as a concrete coating. The possibility of ceramic cullet use as an aggregate to special concretes has been confirmed by the conducted research on specific features. Taking into consideration the available literature, the article presents widely conducted research in the area of the internal structure of concrete designed on the basis of recycled ceramic aggregate, the phase content of individual components, and basic mechanical tests both in normal temperatures and under thermal stress.

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In-situ XRD study of the temperature-dependent early hydration of calcium aluminate cement in a mix with calcite

Cement and Concrete Research ◽

10.1016/j.cemconres.2020.106160 ◽

2020 ◽

Vol 136 ◽

pp. 106160 ◽

Cited By ~ 1

Author(s):

J. Goergens ◽

T. Manninger ◽

F. Goetz-Neunhoeffer

Keyword(s):

Calcium Aluminate ◽

Calcium Aluminate Cement ◽

Temperature Dependent ◽

Early Hydration ◽

In Situ Xrd ◽

Xrd Study ◽

Aluminate Cement

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Physicochemical, Mineralogical, and Mechanical Properties of Calcium Aluminate Cement Concrete Exposed to Elevated Temperatures

Materials ◽

10.3390/ma14143855 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3855

Author(s):

Amirmohamad Abolhasani ◽

Bijan Samali ◽

Fatemeh Aslani

Keyword(s):

Temperature Rise ◽

Calcium Aluminate ◽

Elevated Temperatures ◽

Ultrasonic Pulse Velocity ◽

Pulse Velocity ◽

Calcium Aluminate Cement ◽

Cement Concrete ◽

Sem Images ◽

Strength Deterioration ◽

Aluminate Cement

One commonly used cement type for thermal applications is CAC containing 38–40% alumina, although the postheated behavior of this cement subjected to elevated temperature has not been studied yet. Here, through extensive experimentation, the postheated mineralogical and physicochemical features of calcium aluminate cement concrete (CACC) were examined via DTA/TGA, X-ray diffraction (XRD), and scanning electron microscopy (SEM) imaging and the variation in the concrete physical features and the compressive strength deterioration with temperature rise were examined through ultrasonic pulse velocity (UPV) values. In addition, other mechanical features that were addressed were the residual tensile strength and elastic modulus. According to the XRD test results, with the temperature rise, the dehydration of the C3AH6 structure occurred, which, in turn, led to the crystallization of the monocalcium dialuminate (CA2) and alumina (Al2O3) structures. The SEM images indicated specific variations in morphology that corresponded to concrete deterioration due to heat.

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