Potential application of Portland cement-calcium sulfoaluminate cement blends to avoid early age frost damage

Qin, Ling; Gao, Xiaojian; Zhang, Ailian

doi:10.1016/j.conbuildmat.2018.09.136

Cited by 68 publications

(24 citation statements)

References 39 publications

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“…Manufacture has spread to other countries in recent years, where CSA is often used as a component of blended cements for applications requiring high early-age strength [8]. C 4 A 3 $ + 2 C$H x + (38 − 2x) H → C 6 A$ 3 H 32 + 2 AH 3 x = 0, 0.5, 2 (ettringite formation) (1) According to some studies, when blended with PC, calcium sulfoaluminate cement may raise early-age mechanical strength, reduce shrinkage, control setting time, and improve frost resistance [9][10][11][12]. In CSA + PC blends, the calcium hydroxide released during PC hydration combines with C 4 A 3 $ and calcium sulfate to generate microcrystalline ettringite, which largely offsets shrinkage.…”

Section: Introductionmentioning

confidence: 99%

“…According to some studies, when blended with PC, calcium sulfoaluminate cement may raise early-age mechanical strength, reduce shrinkage, control setting time, and improve frost resistance [ 9 , 10 , 11 , 12 ]. In CSA + PC blends, the calcium hydroxide released during PC hydration combines with C 4 A 3 $ and calcium sulfate to generate microcrystalline ettringite, which largely offsets shrinkage.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration

et al. 2021

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This work analyzes the effect of the presence of 5 wt.% of solid sodium salts (Na2SO4, Na2CO3, and Na2SiO3) on calcium sulfoaluminate cement (CSA) hydration, addresses hydration kinetics; 2-, 28-, and 90-d mechanical strength, and reaction product microstructure (with X-ray diffraction (XRD), and Fourier transform infrared spectroscopy, (FTIR). The findings show that the anions affect primarily the reactions involved. Ettringite and AH3, are the majority hydration products, while monosulfates are absent in all of the samples. All three salts hasten CSA hydration and raise the amount of ettringite formed. Na2SO4 induces cracking in the ≥28-d pastes due to post-hardening gypsum and ettringite formation from the excess SO42– present. Anhydrite dissolves more rapidly in the presence of Na2CO3, prompting carbonation. Na2SiO3 raises compressive strength and exhibits strätlingite as one of its reaction products.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration

et al. 2021

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“…A large number of studies have shown that the addition of crystal seeds of hydration products to cement-based materials is an effective way to improve the early strength of cement. For example, C-S-H seeds are added to Portland cement (Qin et al 2018;Wakeel et al 1999;John et al 2018), hydroxyapatite to calcium phosphate cement (Liu et al 2016), ettringite to sulfoaluminate cement (Yu et al 2019) , and 5-phase (Mg(OH) 2 •MgCl 2 •8H 2 O) to magnesium oxychloride cement (Zhang et al 2017). In recent years, almost all reports on MOS cement show that the formation and interlocking of the 5•1•7 phase in the presence of additives which have obviously retardation effects, contributes the high strength of MOS cement.…”

Section: Introductionmentioning

confidence: 99%

Effects of 5•1•7 Phase Seed Crystal on Performance of Magnesium Oxysulfate Cement

Luo

Zhang

et al. 2019

ACT

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Magnesium oxysulfate (MOS) cement is lightweight, offers fire resistance, and has good aesthetics. Although the addition of citric acid improves the cement's late strength, the concomitant retardation of hydration of MOS by citric acid results in slow setting and low early strength. This may in return decrease the production efficiency of MOS cement products. In this study, 5•1•7 phase (5Mg(OH) 2 •MgSO 4 •7H 2 O) seed crystal (SC) is used as a modifier that works as a seed nucleus and accelerates the hydration of MOS cement in the early stages, in the absence or presence of citric acid. The effect of SC on compressive strength, setting time, and volume change is investigated in detail. X-ray diffraction, scanning electronic microscopy, hydration-heat release rate, and mercury intrusion porosimeter are performed to explain the influence mechanism of SC on the performance of the MOS cement. The results revealed that the in situ formation and growth of the new 5•1•7 phase crystals on the SC surface by the addition of SC can significantly accelerate the setting, improve the 12 h and 28 d compressive strengths, and reduce shrinkage of MOS cement without or with 0.05% citric acid.

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“…In the region of 3800-3000 cm −1 a wide band centered at 3381-3346 cm −1 is observed, whose intensity decreases when GeoSilex raw material content increases. This band can be assigned with the stretching vibration of the water molecules present in the hydrated calcium silicates formed during the hydration reaction of raw materials, WBA and G [52][53][54]. In FTIR spectra, GeoSilex percentages greater than 50 wt%, a peak centered at approximately 3640 cm-1 is also observed, which may be due to the stretching vibration of υ (OH) of unreacted Ca(OH) 2 present in the G by-product [54].…”

Section: Wba-10gmentioning

confidence: 92%

“…In the region between 1800 and 1200 cm −1 , a small band centered at 1645 cm −1 can be observed whose intensity decreases as increasing amounts of GeoSilex are incorporated. This band can be due to the bending modes of the water molecules present in the CSH gel [52][53][54]. In addition, a more intense band centered at approximately 1408-1413 cm −1 is observed.…”

Section: Wba-10gmentioning

confidence: 93%

Wood Bottom Ash and GeoSilex: A By-Product of the Acetylene Industry as Alternative Raw Materials in Calcium Silicate Units

et al. 2020

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The main objective of this research was to obtain calcium silicate units from alternative raw materials, such as the bottom ashes from the combustion of wooden boards (WBA), as a source of silica, and GeoSilex (G), a by-product with low energy and environmental costs generated in the manufacture of acetylene, as a source of lime. Once the raw materials were physically, mineralogically and chemically characterized, calcium silicate units were obtained by mixing different amounts of WBA residue (90–20 wt%) and G by-product (10–80 wt%). The mixtures were compressed at 10 MPa and cured in water for 28 days. The calcium silicate units were subjected to a wide experimental program that included the determination of physical properties (bulk density, apparent porosity and water absorption), mechanical properties (compressive strength), and thermal properties (thermal conductivity). Optimum values are obtained for calcium silicate units that contain a 1/1 WBA/G weight ratio, which have an optimal amount of SiO2 and CaO for the cementation reaction. The 50WBA-50g units have compressive strength values of 46.9 MPa and a thermal conductivity value of 0.40 W/mK. However, all calcium silicate units obtained comply with the European Standard EN 771-2: 2011 to be used as structural building materials.

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Potential application of Portland cement-calcium sulfoaluminate cement blends to avoid early age frost damage

Cited by 68 publications

References 39 publications

Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration

Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration

Effects of 5•1•7 Phase Seed Crystal on Performance of Magnesium Oxysulfate Cement

Wood Bottom Ash and GeoSilex: A By-Product of the Acetylene Industry as Alternative Raw Materials in Calcium Silicate Units

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