Identification of Composite Cement Hydration Products by Means of X-Ray Diffraction

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

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Comparison of FT-IR, Thermal Analysis and XRD for Determination of Products of Cement Hydration

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.168-170.518 ◽

2010 ◽

Vol 168-170 ◽

pp. 518-522 ◽

Cited By ~ 6

Author(s):

Zhi Hua Ou ◽

Bao Guo Ma ◽

Shou Wei Jian

Keyword(s):

Thermal Analysis ◽

Fourier Transform ◽

Cement Hydration ◽

Hydration Products ◽

X Ray Diffraction ◽

Cement Pastes ◽

X Ray ◽

Degree Of Hydration ◽

Ft Ir

Fourier Transform Infrared Spectroscopy (FT-IR), thermal analysis and X-Ray Diffraction (XRD) are commonly performed to study the hydration products in cement pastes. The three methods were compared in this frame to detect products of cement hydration at different ages, especially at early ages (before 24h ages). The results indicate from the present experiment that CH (Calcium hydroxide) can be detected by three methods at all ages; C-S-H can be distinguished by FT-IR at all ages; ettringite may be detected by FT-IR before 24h ages and by XRD at all ages; and monosulphate can be detected by FT-IR before 24h ages. The process of cement hydration, characterized by formation and development of some hydration products, can be clearly observed by three methods. FT-IR is suggested for detecting the major hydration products before 24h ages, FT-IR and XRD are suggested for detecting the major hydration products after 24h ages, and thermal analysis is suggested for analyzing the degree of hydration quantitatively.

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Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration

Molecules ◽

10.3390/molecules26071938 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1938

Author(s):

Luís Urbano D. Tambara Júnior ◽

Janaíde C. Rocha ◽

Malik Cheriaf ◽

Pilar Padilla-Encinas ◽

Ana Fernández-Jiménez ◽

...

Keyword(s):

Cement Hydration ◽

Hydration Products ◽

Reaction Products ◽

X Ray Diffraction ◽

Calcium Sulfoaluminate Cement ◽

Hydration Kinetics ◽

Sodium Salts ◽

X Ray ◽

Calcium Sulfoaluminate ◽

Ettringite Formation

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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Application of Isothermal and Isoperibolic Calorimetry to Assess the Effect of Zinc on Hydration of Cement Blended with Slag

Materials ◽

10.3390/ma12182930 ◽

2019 ◽

Vol 12 (18) ◽

pp. 2930 ◽

Cited By ~ 2

Author(s):

Šiler ◽

Kolářová ◽

Novotný ◽

Másilko ◽

Bednárek ◽

...

Keyword(s):

Cement Hydration ◽

Raw Materials ◽

Isothermal Calorimetry ◽

Real Life ◽

Diffraction Method ◽

X Ray Diffraction ◽

X Ray ◽

Isoperibolic Calorimetry ◽

Poorly Soluble ◽

Furnace Slag

This work deals with the influence of zinc on cement hydration. The amount of zinc in cement has increased over recent years. This is mainly due to the utilization of solid waste and tires, which are widely used as a fuel in a rotary kiln. Zinc can also be introduced to cement through such secondary raw materials as slag, due to increased recycling of galvanized materials. The aim of this work was to determine the effect of zinc on the hydration of Portland cement, blended with ground blast furnace slag (GBFS). This effect was studied by isothermal and isoperibolic calorimetry. Both calorimetry methods are suitable for measurements during the first days of hydration. Isoperibolic calorimetry monitors the hydration process in real-life conditions, while isothermal calorimetry does so at a defined chosen temperature. Zinc was added to the cement in the form of two soluble salts, namely Zn(NO3)2, ZnCl2, and a poorly soluble compound, ZnO. The concentration of added zinc was chosen to be 0.05, 0.1, 0.5, and 1mass percent. The amount of GBFS replacement was 15% of cement dosage. The newly formed hydration products were identified by X-ray diffraction method (XRD).

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XRD (X-Ray Diffraction) Analysis of the Stabilized Ash

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.459.7 ◽

2013 ◽

Vol 459 ◽

pp. 7-10

Author(s):

Hai Ying Zhang ◽

Shu Zhen Li

Keyword(s):

Heavy Metals ◽

Municipal Solid Waste ◽

Solid Waste ◽

Waste Incineration ◽

Municipal Solid Waste Incineration ◽

Hydration Products ◽

X Ray Diffraction ◽

X Ray ◽

Leaching Toxicity ◽

Mineralogical Compositions

MSWI (municipal solid waste incineration) fly ash, generated in incineration process of municipal solid waste, contains lots of heavy metals, which will do harm do the environment if extracted. In this work, the ash is stabilized by cement to reduce leaching toxicity of heavy metals. Besides, mineralogical compositions of the product of different cement / ash ratios after conservation for different period were analyzed by means of XRD (X-ray diffraction). It was found that major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

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Effect and Mechanism of Sodium Fluosilicate on Setting Time of Cement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1978 ◽

2017 ◽

Vol 898 ◽

pp. 1978-1983

Author(s):

Hai Wang ◽

Qian Jin Mao ◽

Yue Gao ◽

Zi Ming Wang ◽

Su Ping Cui

Keyword(s):

Setting Time ◽

Phosphate Fertilizer ◽

Main Function ◽

Hydration Products ◽

X Ray Diffraction ◽

Coagulation Time ◽

X Ray ◽

Retarding Effect ◽

Low Solubility ◽

Sodium Fluosilicate

Sodium fluosilicate (Na2SiF6) is prepared from by-product of phosphate fertilizer production. According to a certain percentage of Na2SiF6 mixed in the cement, the influence of different dosages on the setting time of cement under different water-cement ratio was discussed, and the effect of different forms of fluoride compounds on the setting time of cement were compared. The effect and mechanism of sodium fluosilicate on the hydration products of cement were researched by using the X-ray diffraction analysis and micro electron microscope. Experimental results show that the retarding effect of sodium fluosilicate on the coagulation time had a critical effect, and beyond a certain value, it sharply decreased the setting time. The critical dosage increased with the increase of water-cecment ratio. Compared with the retarding effect of Na2SiF6、MgSiF6、NaF and CaF2 on the coagulation time of cement, Na2SiF6 was the best. The incorporation of Na2SiF6 does not change the types of the hydration products, the main function of FN is hydrolyzed with Ca2+ ions to form CaF2 with a very low solubility.

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Modification Effects of Nano-CaCO3 on Engineering Performance of Cement Grouts

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.18487 ◽

2020 ◽

Vol 20 (8) ◽

pp. 5043-5048

Author(s):

Xiang Qiu ◽

Huangbin Jiang ◽

Guijin Zhang

Keyword(s):

Yield Stress ◽

Cement Hydration ◽

Setting Time ◽

X Ray Diffraction ◽

Bleeding Rate ◽

X Ray ◽

Initial Setting Time ◽

Study Results ◽

Initial Setting ◽

Cement Grouts

Efficacy of added nano-CaCO3 (NC) on engineering performances, including fluidity, initial setting time, bleeding rate and yield stress of cement grouts was investigated in this study. Results showed that the fluidity and bleeding rate for NC-cement (NCC) composite grout first decreased with increased NC content (i.e., ratio of NC mass to cement mass) and then slightly recovered as the NC content exceeded 2%. The initial setting time was always reduced while the yield stress increased with increased NC content. The microstructure of NCC was analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the NC can promote the cement hydration, but an excess amount of NC will inhibit the cement hydration and affect the engineering performances of cement grouts. The optimum NC content for modification of cement grouts was thus 2%.

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