Special Aspects of Hydration Process of Microfine Cement

2015 ◽  
Vol 725-726 ◽  
pp. 578-583 ◽  
Author(s):  
Irina Ivanova ◽  
Andrey Pustovgar ◽  
Aleksey Eremin ◽  
Aleksey Adamtsevich
Keyword(s):  
Powder Diffraction ◽  
Isothermal Calorimetry ◽  
Mineralogical Composition ◽  
Hydration Process ◽  
Hydration Products ◽  
Cement Pastes ◽  
X Ray ◽  
Microfine Cement ◽  
Microfine Cements

The aim of the present research was to determine special features of hydration process of two commercial microfine cements compared to CEM I 42.5N cement with similar mineralogical composition. The influence of cement fineness and composition on the hydration process was investigated by isothermal calorimetry of cement pastes and quantitative X-ray powder diffraction of hydration products at 1, 3, 7, 14 and 28 days.

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

2010 ◽  
Vol 168-170 ◽  
pp. 518-522 ◽  
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.

Effect of Pair-Mineralizer on the Reaction of Alite and Calcium Langbeinite Formation

2006 ◽  
Vol 510-511 ◽  
pp. 622-625
Author(s):  
Woo Teck Kwon ◽  
Young Phil Kim ◽  
Y. Kim ◽  
Soo Ryong Kim ◽  
Seong Youl Bae
Keyword(s):  
Powder Diffraction ◽  
Calcium Silicate ◽  
Mineralogical Composition ◽  
Experimental Results ◽  
Silicate Minerals ◽  
X Ray

This paper investigates the effect of the pair-minerializer (CaSO4,-CaF2) on the reaction of alite, belite and calcium langbeinite formation with different alkali and sulfate contents. A set of clinker samples was prepared by adding laboratory grade reagents of (NH4)2SO4, CaF2 and K2CO3 to the cement raw mixes. The mineralogical composition of clinker was analyzed by X-ray powder diffraction, and the quantity of minerals was evaluated by using TOPAS software. As the experimental results, the total amount of calcium silicate minerals was rapidly increased with the addition of F and SO3 components simultaneously as pair-mineralizer with K2O more than the value which mineralizer was added separately. Also, in the case of adding K2O only to the raw mixes, the amount of alite is decreased after clinkering. However, if alkali (K2O) and pair-minerializer (CaSO4,-CaF2) were added simultaneously, the quantity of alite and calcium langbeinite mineral increased because of the formation of stable clinker minerals by the reaction of alkali (K2O) and sulfate.

Hydration of sodium phosphate-modified high alumina cement

1994 ◽  
Vol 9 (5) ◽  
pp. 1291-1298 ◽  
Author(s):  
Weiping Ma ◽  
Paul W. Brown
Keyword(s):  
Isothermal Calorimetry ◽  
High Strength ◽  
High Alumina ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Alumina Cement ◽  
X Ray ◽  
Morphological Variations ◽  
High Alumina Cement ◽  
Sodium Phosphates

High strength can be achieved in high alumina cement (HAC) through the incorporation of phosphate-based additions at levels of 10 and 20 wt. %. In order to establish the mechanism that results in higher strength, the effects of a variety of condensed sodium phosphates (NaPO3)n, (NaPO3)n · Na2O, Na5P3O10, and (NaPO3)3 were studied. The influence of these additions on the kinetics of hydration was studied using isothermal calorimetry. The phosphatic additions enhanced reactivity, but x-ray diffraction analyses did not reveal evidence of new crystalline phosphate-containing hydration products. Microstructural evolution was examined in real time using environmental SEM, and hydration products exhibiting distinct morphologies were observed. The features exhibited ranged from amorphic to polygonal shapes, plates, and fibers. These frequently formed between crystalline calcium aluminate hydrate grains and by doing so appear to provide a means to enhance the strengths of these cements. In spite of the morphological variations, companion energy dispersive x-ray analysis showed that the compositions of these products did not vary widely. Their ranges of compositions are 52-60 wt. % Al2O3, 20-26 wt. % P2O5, and 20-24 wt. % CaO.

Utilization of CFB Fly Ash in Eco-Cement: Mechanical Properties and Microstructural Analysis

2010 ◽  
Vol 150-151 ◽  
pp. 885-889 ◽  
Author(s):  
Xiao Ming Liu ◽  
Yu Li ◽  
Ling Ling Zhang ◽  
Da Qing Cang
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Circulating Fluidized Bed ◽  
Microstructural Analysis ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
X Ray ◽  
Xrd Techniques ◽  
Furnace Slag

The disposal of circulating fluidized bed (CFB) fly ash has been a serious environmental problem in the development of our society. In this work, the feasibility of recycling CFB fly ash as a blended material incorporating blast furnace slag (BFS), clinker and gypsum for the preparation of Eco-cement has been investigated. The mechanical properties of CFB fly ash based Eco-cements, including CFB fly ash–clinker system, CFB fly ash–ground BFS system, and CFB fly ash–ground BFS–clinker system, were evaluated in this paper. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to analyze the microstructural changes and the hydration products of the CFB fly ash based Eco-cement pastes. The results indicated that it is feasible to use CFB fly ash along with BFS and clinker to produce Eco-cement. The hydration products of CFB fly ash based Eco-cement are mostly ettringite and amorphous C-S-H gel, which are principally responsible for the strength and structure development of CFB fly ash based Eco-cement in the hydration process.

Influence of Nano-SiO2 and Nano-TiO2 on Early Hydration of Calcium Sulfoaluminate Cement

2014 ◽  
Vol 599 ◽  
pp. 39-45 ◽  
Author(s):  
Bao Guo Ma ◽  
Hai Nan Li ◽  
Yan Chao Zhu ◽  
Lei Han ◽  
Xiang Guo Li
Keyword(s):  
Isothermal Calorimetry ◽  
Sem Analysis ◽  
Cement Stone ◽  
X Ray Diffraction ◽  
Calcium Sulfoaluminate Cement ◽  
Early Hydration ◽  
Cement Pastes ◽  
X Ray ◽  
Calcium Sulfoaluminate ◽  
The Difference

Calcium sulfoaluminate (CSA) cements were currently receiving a lot of attention because their manufacture produced less CO2 than ordinary Portland cement (OPC). However, it was essential to understand all parameters which might affect the hydration process. This work dealt with the effect of two nanostructured materials, such as nanoSiO2 (NS) and nanoTiO2 (NT), on the properties of CSA pastes during early hydration. Isothermal calorimetry, X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were used to analyze the pastes. Results indicated that the influence of NS and NT on the early hydration of CSA showed different: when NS and NT were added by 5% (mass fraction), the early hydration of CSA cement can be significantly promoted by NS, and slightly accelerated by NT. X-ray diffraction and SEM analysis results showed that both of NS and NT can improve the microstructure of the cement pastes, which made the cement stone more uniform and dense. For the difference, during cement hydration, except for nucleation function, NS had a high pozzolanic activity. Whereas,the effect of NT on microstructure of hardened CSA-cement was mainly due to its seeding effect.

X-ray powder diffraction of mineral pigments and medicines from the 17th century pharmacy (Spezieria) Santa Maria della Scala in Rome, Italy

2018 ◽  
Vol 33 (4) ◽  
pp. 270-278
Author(s):  
Giovanni Cavallo ◽  
Maria Luisa Vázquez de Ágredos Pascual
Keyword(s):  
Powder Diffraction ◽  
Mineralogical Composition ◽  
17Th Century ◽  
Inorganic Materials ◽  
Research Project ◽  
X Ray ◽  
Santa Maria ◽  
Material Preparation ◽  
Inorganic Fraction

The pharmacy (spezieria) Santa Maria della Scala was founded in Rome by the Discalced Carmelites Order in the 17th century, and during the 18th and 19th centuries it became the official supplier of medicines for Vatican Popes. The laboratory and the cases of this spezieria still preserve glass jars with organic and inorganic materials, which were presumably used for medicine and artistic material preparation, whose composition is unknown to date. A research project was initiated with the aim to study the stored materials and the role that the pharmacy played in regional, national and international contexts. In this manuscript, the compounds were analysed through X-ray powder diffraction with the scope to derive the quantitative mineralogical composition of the inorganic fraction, their possible use in pharmacopoeias and as mineral pigments. Most of the analysed samples are salts (sulphates, chlorides, carbonates, phosphates, borates, sulphides), sulphates being the predominant class; oxides were also detected.

scholarly journals Effect of the water/binder ratio on the hydration process of Portland cement pastes with silica fume and metakaolin

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Mara Monaliza Linhares Pereira ◽  
Ana Luiza Rocha de Souza ◽  
Valdirene Maria Silva Capuzzo ◽  
Rodrigo de Melo Lameiras
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Hydration Process ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
X Ray ◽  
Binder Ratio ◽  
Water Binder Ratio ◽  
Mineralogical Phases

abstract: The microstructure of cement pastes is important to understand the effect of some parameters in the hydration process. In this context, this study had as objective to evaluate the effect of different water/binder (w/b) ratios in the hydration process of cementitious pastes produced with and without incorporation of silica fume and metakaolin. The pastes were obtained with water/binder ratios of 0.3, 0.4 e 0.5, with replacement, by weight, of Portland cement for silica fume and metakaolin, in the contents of 10% and 20%, respectively. It was performed the X-ray diffraction test of the pastes in the ages of 1, 3, 7, and 28 days, to evaluate the hydration evolution of the cementitious materials. According to the results obtained, it was observed that the cementitious pastes presented similar mineralogical phases, except for the pastes containing metakaolin due to the formation of new aluminate phases. With the increase of the water/binder ratio, the pozzolanic reactions and hydration occurred in greater proportion, standing out the metakaolin with greater reactivity.

Quantitative X-Ray Diffraction Analysis of Anhydrous and Hydrated Portland Cement – Part 1: Manual Methods

2015 ◽  
Vol 1087 ◽  
pp. 493-497 ◽  
Author(s):  
Duong D. Nguyen ◽  
Liam Devlin ◽  
Pramod Koshy ◽  
Charles C. Sorrell
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Internal Standard ◽  
Mineralogical Composition ◽  
Xrd Analysis ◽  
Internal Standard Method ◽  
X Ray Diffraction ◽  
Accurate Analysis ◽  
Cement Pastes ◽  
X Ray

Portland cement is one of most important construction and building materials and its properties depend strongly on the mineralogical composition. Consequently, accurate analysis of the mineralogical composition of anhydrous Portland cement is crucial for both product quality control and optimisation of performance following initial hydration. In the latter sense, analysis of the mineralogical composition of hydrated Portland cement paste is critical to understand (1) the mechanism and kinetics of hydration of unmodified pastes and those modified with additives and (2) the resultant properties of cement pastes, mortars, and concretes. Such analyses typically are undertaken by quantitative X-ray diffraction (XRD).The present work reviews current practices in quantitative XRD analysis of anhydrous and hydrated Portland cement. To this end, Part 1 of this two-part work briefly mentions the point-counting method and the Bogue calculation method. The more commonly applied internal standard method and reference intensity ratio (RIR) method are discussed in more detail.

Artefacts from Ban Chiang, Thailand: pottery with hematite-red geometric patterns

2020 ◽  
Vol 235 (11) ◽  
pp. 559-568
Author(s):  
Ulrich Bismayer ◽  
Sutham Srilomsak ◽  
Yaowapa Treekamol ◽  
Waraporn Tanthanuch ◽  
Kanokwalee Suriyatham
Keyword(s):  
Ftir Spectroscopy ◽  
Bronze Age ◽  
Iron Age ◽  
Powder Diffraction ◽  
Mineralogical Composition ◽  
Optical Reflectance ◽  
Thin Sections ◽  
X Ray ◽  
Geometric Patterns ◽  
Ban Chiang

AbstractBan Chiang () is an extensively studied archeological site in Northeast Thailand, Udon Thani Province, which became a UNESCO world heritage in 1992. Depending on their production period ceramic artefacts show characteristic patterns at the surface which may be interpreted as iconographic motifs for the site. Two ceramic samples, excavated in 2003, from different periods were re-investigated, previously studied by Tanthanuch W., Pattanasiriwisawa W., Somphon W., Srilomsak S. Synchrotron studies of Ban Chiang ancient pottery. Suranaree J. Sci Technol. 2011, 18, 15–28 who focussed on thermal firing and redox-conditions. Shards selected for this study were sample 5412-S6E15 dated from Bronze Age (ca. 1000–300 BC) with yellow-brown, paint-free surface and a younger sample 8027 from Iron Age (ca. 300 BC–200 AD) with red painted design carrying pictorial patterns typical for the Ban Chiang ceramics. The surface material and colour of both shards was studied in detail using optical reflectance, FTIR spectroscopy and X-ray powder diffraction. Thin sections were used to determine the thickness of the red paint and the elemental composition of the surface using an electron microprobe. Chemical composition of sample 5412-S6E15 consists as oxides of elements mainly of SiO2 and Al2O3 (representing ca. 59 and 20 wt. %) and that of the red colour of the youngest sample 8027 consists mainly of SiO2, Al2O3 and Fe2O3 (representing ca. 52, 13 and 13 wt. %), the average composition adjacent to the red painted area has ca. 72 wt. % SiO2, ca. 10 wt. % Al2O3 and only 2 wt. % Fe2O3. X-ray powder diffraction, FTIR spectroscopy and optical reflectance measurements confirm hematite in the mineralogical composition of the red pigment of shard 8027.

Similarities and Differences in Shale, Aggregate Mixes and Concrete Containing Fly Ash

1988 ◽  
Vol 136 ◽  
Author(s):  
Petros E. Zenieris ◽  
Joakim G. Laguros
Keyword(s):  
Fly Ash ◽  
Maximum Level ◽  
Hydration Process ◽  
Strength Development ◽  
Chemical Agent ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Practical Result ◽  
X Ray ◽  
The Matrix

ABSTRACTFly ash technology has been very effective in providing stability in roadway base courses composed either of shale or aggregate materials, and also in partly replacing Portland cement in concrete. X-ray diffractometry and scanning electron microscopy observations indicate that there are certain similarities among these three types of mixes concerning the hydration process; on the other hand, there is evidence of distinct differences in the hydration products which are found to act either as a filler, a chemical agent, or both. Fly ash suppresses the intensity of the clay minerals in shale, speeds up the hydration process in concrete and acts partly as a filler in aggregate mixes. The net practical result is strength development which varies not only in terms of the maximum level attained, but also in regard to its rate. The conversion of ettringite to monosulfoaluminate proceeds at a rate which is considered high in concrete, moderate in aggregate mixes, and moderate to low in shale. X-ray diffraction analyses help to identify other dissimilarities in the minerals produced. The modification which takes place in the fabric and the matrix of the mixes is morphologically the same; in contrast, the growth of crystallites at the “particle”/fly ash interface is explicitly different. Preliminary quantification of matrix changes resulting from new hydration products is also explored.

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