Cement thermal analysis

The action of heat on these cements is complex (Abdelrazig Sharp, 1988). The principal sequence based on XRD and thermal analysis is shown in Figure 6.10. 

Bayne, S. C. Greener, E. H. (1985). ZnO cements phase identification by thermal analysis. Dental Materials, 1, 165-9. 

El-Tahawi, H. M. Craig, R. G. (1971). Thermal analysis of zinc oxide-eugenol cement. Journal of Dental Research, 50, 430-5. 

This book contains papers from the Fourth International Conference on Computational Methods and Experiments in Materials Characterisation which brought researchers who use computational methods, those who perform experiments, and of course those who do both, in all areas of materials characterisation, to discuss their recent results and ideas, in order to foster the multidisciplinary approach that has become necessary for the study of complex phenomena. The papers in the book cover the follow topics Advances in Composites Ceramics and Advanced Materials Alloys Cements Biomaterials Thin Films and Coatings Imaging and Image Analysis Thermal Analysis New Methods Surface Chemistry Nano Materials Damage Mechanics Fatigue and Fracture Innovative Computational Techniques Computational Models and Experiments Mechanical Characterisation and Testing. 

A comprehensive study on the formation of cement catalytic systems was performed by X-ray diffraction, thermal analysis, electronic diffuse-reflectance spectroscopy and IR-spectroscopy. Table 1 presents characteristics of some of the investigated catalytic systems. 

Ramachandran, V. S., Differential Thermal Analysis in Cement Chemistry, Chemical Publishing Co., New York, 1969. 

Figure 5 Thermal analysis curve for high alumina cement...

The Thermal Methods Group of the Royal Society of Chemistry, which was founded in 1965, has a tradition of education in thermal analysis dating back to its first residential thermal analysis school held at the Cement and Concrete Research Association in 1968. The Group has continued to be at the forefront of thermal education through the organisation of schools, specialist meetings and both national and international conferences. 

Abstract, The fundamentals of the emanation thermal analysis are described and sample preparation for different inert gas operations are considered and discussed. The mechanisms of releasing inert gases from solids are exposed in relation to the measurements of the diffusion of gases in solid samples. Thus, the applications to ceramics investigation, surface roughness and defects of powders are described. Applications for glasses, clay minerals and cements are discussed from our own experimental work. The corrosion on materials can be also investigated with this method. 

Palon, M.T., and Majling, J. (1996) Effect of sulfate, calcium and aluminum ions upon the hydration of sulfoaluminate belite cement. Journal of Thermal Analysis 46,549-556. 

Goswami, G Padhy, B.P., and Panda. J.D. (1989) Thermal analysis of spurrite from a rotary cement lain. J. Therm. Anal, 35 (4), 1129-1136. 

Fig. 17.3 Differential thermal analysis (DTA) of concrete sample ground to <80 mesh. Area of cement peak is proportional to amount of cement in sample...

Musa, N.M., 2014. Thermal analysis of cement paste partially replaced with neem seed husk ash. International Journal of Scientific and Engineering Research 5 (1). ISSN 2229-5518. 

The performance of concrete depends on the quality of the ingredients, their proportions, placement, and exposure conditions. For example, the quality of the raw materials used for the manufacture of clinker, the calcining conditions, the fineness and particle size of the cement, the relative proportions of the cement phases, and the amount of mixing water influence the physico-chemical behavior of the hardened cement paste in concrete. In addition, the cementtype, nature of fine and coarse aggregates, water, temperature of mixing, admixture, and the environment will determine the physical, chemical, and durability aspects of concrete. Thermal analysis techniques are widely applied to investigate the physico-chemical behaviors of cement compounds, cement, and concrete subjected to various conditions. 

Feldman, R. F., and Ramachandran, V. S., Differentiation of Interlayer and Absorbed Water in Hydrated Portland Cement of Thermal Analysis, Cem. Conor. Res., 1 607-620(1971)... 

In the production of sulfoaluminate cement from raw materials such as limestone, bauxite, and anhydrite, DTA has been used to monitor the reactions that take place when these mixes are heated to a temperature of 1025°C. By applying DTA and XRD it was found that the dehydration and decomposition of bauxite occurs at 530 C. At about 900 C calcium carbonate is decomposed to CaO and it reacts with a-Si02to form C2AS. At a higher temperature, C2AS reacts with CaS04 to form calcium sulfoaluminate and Thermal analysis has also been applied to... 

Thermal analysis data on the hydration of dicalcium silicate are sparse because it is time consuming to follow the reaction of this phase which is very slow. The characteristic products obtained during its hydration are not much different from those formed in C3S hydration. Also, the major strength development that occurs in cement in the first 28 days (a period of practical significance) is mainly due to the tricalcium silicate phase. TG, DTG, and DTA investigations of C2S were carried out by Tamas.t The sensitivity of the instrument had to be increased substantially to detect the peaks due to the decomposition of calcium hydroxide and calcium carbonate, especially at earlier times. In Fig. 21, the DTA, DTG, and TG curves of C2S hydrated for 21 days and 200 days are given. A comparison of these peaks with those obtained from C3S pastes shows substantial differences in the intensity value of the peaks. The 200 day C2S sample shows a weight loss of 4%, whereas C3S hydrated for 21 days indicates a loss of 13%. 

Kalousek, et al., in an extensive work on the thermal analysis of cements concluded that both low and high aluminate sulfate forms ultimately disappear and are incorporated into the C-S-H gel. 

The potentiality of the emanation thermal analysis for the investigation of the hydration of cement and cement compounds has been discussed by Balek.t This technique is based on the measurement of radioactive gases released from the hydrating phase. The amount of gas released depends on the physico-chemical processes taking place in the solid. A quantitative estimation of the rate of hydration of cement and C3S at early stages has been obtained. 

Bhatty, J. L, Review of Application of Thermal Analysis to Cement-Admixture Systems, ThermochimicaActa, 189 313-350 (1991)... 

Balek, V., The Hydration of Cement Investigated by Emanation Thermal Analysis, Thermochimica Acta, 72 147-158 (1984)... 

Bensted, J., Some Instrumental Investigation of Portland Cement Hydration-Part II Differential Thermal Analysis (DTA), II Cemento, 76 117-126 (1979)... 

Ramachandran, V. S., Thermal Analysis of Cement Components Hydrated in the Presence of Calcium Carbonate, ThermochimicaActa, 127 385-394 (1988)... 

Thermal analysis techniques have been applied widely for the investigation of the role of admixtures, espeeially that related to the hydration of cement and cement components. AppUcation of thermal analysis permits determination of the heat of reaction, mechanism of reaction, kinetics of reactions, compatibility of admixtures with cements, prediction of some properties, durability problems, material characterization and selection, development of new admixtures, quick assessment of some physical properties, etc. In some instances, they 5deld results that are not possible to obtain with the use of other teehniques. 

One of the limitations to the wider use of calcium chloride in reinforced concrete is that, if present in larger amounts, it promotes corrosion of the reinforcement unless suitable precautions are taken. The use of calcium chloride is banned in many countries. There is, hence, a continuing attempt to find an alternative to calcium chloride, one equally effective and economical, but without its limitations. A number of organic and inorganic compoimds including aluminates, sulfates, formates, thiosulfates, nitrates, silicates, alkali hydroxides, carbonates, halides, nitrites, calcium salts of acetic acid, propionic acid, butyric acid, oxalic acid and lactic acid, urea, glyoxal, triethanolamine, and formaldehyde have been suggested. However, practical experience and research on these admixtures are limited. The effect of these compounds on the hydration of individual cement compoimds and cement has been widely studied by thermal analysis techniques. 

Zivica, V., Stabilization of Copper Refining Waste in Cement Matrix Using Thermal Analysis,/. Therm. Analysis, A6 6 -6 l (19%)... 

Milestone, N. B., Identification of Concrete Admixtures by Differential Thermal Analysis, Cement Concr. Res., 14 207-214 (1984)... 

The main methods of investigating the effect of supplementary materials and other additions on cement hydration include XRD, SEM, NMR, Mossbauer spectroscopy, IR, and thermal analysis. Poorly crystallized products that form in these materials are advantageously investigated by TG, DTG, DTA, DSC, and conduction calorimetry. Thermal methods have also been suggested for characterization of the supplementary and other materials. 

---