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The paper gives coverage on approach to the optimization of selection process of constituents for high performance concrete (HPC) and mortars. There is shown the example selection of cement, mineral and chemical admixtures, as the most costly and influential on concrete, from the point of their maximum efficiency, measured by flowability and compressive strength increasing indexes. Method combines models for determination of activity indexes with simple stochastic equations obtained at mathematical treatment of experimental results.
W artykule przedstawiono sprawozdanie na temat podejścia do optymalizacji procesu selekcji składników do betonu wysokowartościowego (BWW) oraz zapraw. Pokazany jest wybrany przykład stosunku cementu, minerałów i chemicznych domieszki, jako najbardziej kosztownych i wpływowych na beton, od punktu maksymalnej aktywności, mierzonej przez wzrostem indeksów zdolności do płynięcia i do wytrzymałości na ściskanie. Metoda łączy w sobie modele do oznaczania aktywności indeksów z prostymi równaniami stochastycznymi uzyskanymi przy obliczeniu wyników eksperymentalnych.
The aim of this paper was to characterize the structure of fragments of ceramic vessels found in the Early Iron Age strongholds from 7th and 5th century B.C. at Starosiedle in Poland and at Biehla in Germany. This research was done in collaboration between material scientists from the Technical University of Warsaw and archaeologists from the Institute of Archaeology and Ethnology of the Polish Academy of Science (PAN). The main idea of our work is to adapt the methodology employed to characterize structure and properties commonly used in materials science and engineering to ancient pottery. In this paper preliminary results and examples of the application of fractography to the study of ancient pottery are presented. Selected ceramic fragments were examined by light and scanning electron microscopy. The fractographic examinations of vessel fractures permitted the identification of the shape, color, and admixture distribution in the sam- ples. It also enabled us to observe the structure of the ceramic matrix and in particular cracks and delaminations (Fig. 1÷3). Observations combined with the point analysis of the chemical composition performed with the help of a scanning electron microscope supplemented the examinations of the kind and structure of the admixtures (Fig. 4÷6). In conclusion, our investigations have demonstrated that the application of materials engineering techniques to the study of prehistoric pottery is beneficial for both archaeology and materials and engineering science as both sides can profit from the different point of view offered by the other. For the archaeologists, the results of materials science techniques for the examination of ancient pottery will permit establishing the relations between ceramic structure and the manufacturing techniques. On this basis, conclusions can be reached about the development of pottery technology in the context of the contemporary social and cultural background. For the materials and engineering scientists this collaboration allows them to study materials which have been affected by their deposition context for thousands of years, and thus offers them the chance to predict the effects of long-term storage in particular context for modern materials.
This publication contains the results of research conducted in 1997 on Hans Glacier in chosen points. The research included mineral particles of diameter bigger than 1um. The average sections of the particles and their average volumes were calculated Particle size distribution were also made. Based on the research it was found that there were considerable difference in particle size distribution of particles ind different points of the glacier.
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