Early Hydration Heat of Calcium Sulfoaluminate Cement with Influences of Supplementary Cementitious Materials and Water to Binder Ratio

Zhang, Jun; Ke, Guoju; Liu, Yuzhang

doi:10.3390/ma14030642

Cited by 29 publications

(21 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main differences are in the number of exothermic peaks, their values and the occurring time. The several heat flow peaks in CSA cement are reported in other tests [19,46,47], and the results from the presented study confirm this tendency.…”

Section: (Opc)supporting

confidence: 88%

“…The reaction is usually characterized by a high heat evolution in the first several minutes from adding water to the cement, due to dissolution and C 3 A reaction with gypsum, resulting in ettringite. After that, the reaction slows down for up to several hours (induction phase), to restart with alite hydration, followed by the belite and C 3 A hydration [46,48]. In the case of CSA cement, the main constituents of the CSA clinker are ye'elimite and gypsum, with low amounts of belite present.…”

Section: (Opc)mentioning

confidence: 99%

“…In the case of CSA cement, the main constituents of the CSA clinker are ye'elimite and gypsum, with low amounts of belite present. The process of hydration of CSA cement is swift and results mostly in the production of ettringite (AFt), monosulphate (AFm), crystalline aluminum hydroxide (AH 3 ) and stratlingite (C 2 ASH 8 ), with small amounts C-S-H phase appearing late in hydration process due to belite reaction [46]. This results in a significantly faster start of the reaction than in the case of OPC, a short induction phase and high hydration peaks [18,20,25].…”

Section: (Opc)mentioning

confidence: 99%

See 2 more Smart Citations

Thermal Properties of Calcium Sulphoaluminate Cement as an Alternative to Ordinary Portland Cement

2021

View full text Add to dashboard Cite

This paper presents the results of research into the heat of hydration and activation energy of calcium sulphoaluminate (CSA) cement in terms of the dependence on curing temperature and water/cement ratio. Cement pastes with water/cement ratios in the range of 0.3–0.6 were tested by isothermal calorimetry at 20 °C, 35 °C and 50 °C, with the evolved hydration heat and its rate monitored for 168 h from mixing water with cement. Reference pastes with ordinary Portland cement (OPC) were also tested in the same range. The apparent activation energy of CSA and OPC was determined based on the results of the measurements. CSA pastes exhibited complex thermal behaviour that differed significantly from the thermal behaviour of ordinary Portland cement. The results show that both the w/c ratio and elevated temperature have a meaningful effect on the heat emission and the hydration process of CSA cement pastes. The determined apparent activation energy of CSA revealed its substantial variability and dependence, both on the w/c ratio and the curing temperature.

show abstract

Section: (Opc)supporting

confidence: 88%

Section: (Opc)mentioning

confidence: 99%

Section: (Opc)mentioning

confidence: 99%

See 1 more Smart Citation

Thermal Properties of Calcium Sulphoaluminate Cement as an Alternative to Ordinary Portland Cement

2021

View full text Add to dashboard Cite

show abstract

“…It is particularly important in the case of prefabricated elements, where the time of installation into the structure is sometimes counted not in days but even in hours after their formation [47][48][49]. On the other hand, besides mechanical tests, the study of hydration heat and shrinkage of the cement matrix are the basic tests to determine the influence of additives and admixtures-that is, internal factors-on the properties of the cement composite at a very early age [62,63].…”

Section: Significance Of the Studymentioning

confidence: 99%

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

Szóstak

Golewski

2021

Materials

View full text Add to dashboard Cite

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.

show abstract

“…In addition, the sulphate content and type affect the kinetic of silicates in general [20,21], and belite in particular [18,22], by retarding their hydration with the increase in sulphate dissolution. The decrease of water-to-cement (w/c) ratio is a positive strategy to enhance mechanical strengths [23,24] but its effect on hydration kinetics is still not fully understood, especially the effect on phase assemblage and microstructural development [25]. Moreover, the relationship among the complex phase assemblage, the microstructure and the mechanical properties is still a challenge in common systems [26,27], and even more in BYF.…”

Section: Introductionmentioning

confidence: 99%

Effect of Boron and Water-to-Cement Ratio on the Performances of Laboratory Prepared Belite-Ye’elimite-Ferrite (BYF) Cements

et al. 2021

View full text Add to dashboard Cite

The effect of superplasticiser, borax and the water-to-cement ratio on BYF hydration and mechanical strengths has been studied. Two laboratory-scale BYF cements—st-BYF (with β-C2S and orthorhombic C4A3S¯) and borax-activated B-BYF (with α’H-C2S and pseudo-cubic C4A3S¯)—have been used, and both show similar particle size distribution. The addition of superplasticiser and externally added borax to BYF pastes has been optimised through rheological measurements. Optimised superplasticiser contents (0.3, 0.4 and 0.1 wt % for st-BYF, B-BYF and st-BYF with externally added 0.25 wt % B2O3, respectively) result in low viscosities yielding homogeneous mortars. The calorimetric study revealed that st-BYF is more reactive than B-BYF, as the values of heat released are 300–370 J/g and 190–210 J/g, respectively, after 7 days of hydration; this fact is independent of the water-to-cement ratio. These findings agree with the higher degree of hydration at 28 days of β-C2S in st-BYF (from 45 to 60%) than α’H-C2S in B-BYF (~20 to 30%). The phase assemblage evolution has been determined by LXRPD coupled with the Rietveld method and MAS-NMR. The formation of stratlingite is favoured by increasing the w/c ratio in both systems. Finally, the optimisation of fresh BYF pastes jointly with the reduction of water-to-cement ratio to 0.40 have allowed the achieving of mortars with compressive strengths over 40 MPa at 7 days in all systems. Moreover, the st-BYF mortar, where borax was externally added, achieved more than 70 MPa after 28 days. The main conclusion of this work does not support Lafarge’s approach of adding boron/borax to the raw meal of BYF cements. This procedure stabilises the alpha belite polymorph, but its reactivity, in these systems, is lower and the associated mechanical strengths poorer.

show abstract

Early Hydration Heat of Calcium Sulfoaluminate Cement with Influences of Supplementary Cementitious Materials and Water to Binder Ratio

Cited by 29 publications

References 28 publications

Thermal Properties of Calcium Sulphoaluminate Cement as an Alternative to Ordinary Portland Cement

Thermal Properties of Calcium Sulphoaluminate Cement as an Alternative to Ordinary Portland Cement

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

Effect of Boron and Water-to-Cement Ratio on the Performances of Laboratory Prepared Belite-Ye’elimite-Ferrite (BYF) Cements

Contact Info

Product

Resources

About