Anastasia Capotosto, Giacomo Russo, Alessandro Tarantino
Lime stabilization is a widely recognized improvement technique for reusing fine-grained soils unsuitable for earthwork constructions. After adding lime to an unsaturated soil, the two types of reactions take place, short term effects due to change in pore water chemistry and long-term effects due to pozzolanic reactions. In the last decades, attention has mainly been given to the mechanical long-term effects induced by pozzolanic reactions. On the other hand, short-term mechanicals effects have received little attention. The aim of this work is to investigate microstructural changes in the...
TC4 International Workshop on Metrology for Geotechnics 2016
· TC4
· 2016
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Marta Di Sante
It is widely known that lime treatment of clayey soils enhances mechanical and hydraulic characteristics of soils. In soil-lime systems, this improvement is due to a sequence of chemical processes that results in reaction products detectable at meso- and micro-scale. Therefore the contribution of experimental techniques such as Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Mercury Intrusion Porosimetry turns out to be essential to analyze the results of geotechnical tests and to understand the behaviour of soil-lime mixtures. After a brief review of literature on the...
TC4 International Workshop on Metrology for Geotechnics 2016
· TC4
· 2016
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George E. Christidis
Smectitic clays display remarkable properties when dispersed in water due to their surface charge. This charge stems from various substitutions in their crystal structure both in tetrahedral and octahedral sites, which yield layer charge. Although the layer charge has been linked to several water-rock properties of smectitic clays namely cation exchange capacity, swelling and viscosity, it is a microscopic property referring to the unit cell i.e. at atomic level. In contrast smectite-water properties are macroscopic and refer to smectite particles. Therefore recently we introduced the term...
TC4 International Workshop on Metrology for Geotechnics 2016
· TC4
· 2016
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Dimitri Deneele
Composed of discrete particles and particle groups, a soil mass or a reconstituted soil mass should be considered as a continuum for analysis and design. Even with the development of numerous techniques of investigations, the link between the macroscopic behavior and the particle arrangement in soils is still under debate owing the complexity of the system, the different levels of investigations. However the shape of the particles, the particle arrangements, the strength of the particles or the water content of a soil govern the soil microstructure or fabric and the macroscopic properties as...
TC4 International Workshop on Metrology for Geotechnics 2016
· TC4
· 2016
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Colin A. Taylor, Adam J. Crewe, George Mylonakis
We are at the maturity convergence point of a set of actuation, control, instrumentation and data analysis technologies that make it feasible to construct laboratory experimental rigs that will allow us to address key controlling uncertainties in SFSI assessment and design, which can only be addressed by testing at, or near to, prototype scale. This paper will explore the process of innovation that must be established in order to integrate these enabling technologies and thereby create novel test facilities that offer new, high value, capabilities.
TC4 International Workshop on Metrology for Geotechnics 2016
· TC4
· 2016
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Jian-Qiang Hu, Yong-Guo Zhang, Huan-Qinqin Zhu, Shi-Zhao Yang
Catalytic thermometric titrition has been developed for the determination of the acidity of oils. The amounts of oil, concentration and delivery rate of titrant, volumes and types of thermometric indicator were investigated. The results show that mixture of acetone and chloroform used as indicator exhibits strongly exothermic effects to reflect end point obviously. The method is fast, easy to use, accurate, and highly reproducible to measure lower acidity in non-coloured and coloured oils.
XXI IMEKO World Congress
· TC24
· 2015
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Adel B. Shehata, Essam A. Kishar, Randa N. Yamani
Matrix certified reference materials are versatile tools to support quality, correctness and credibility of measurement results. CRMs are used to provide the traceability of the measurement results to the SI unit. Seven low alloy steel certified reference materials were developed by the national institute of standards (NIS), Egypt. Homogeneity and stability were studied by x-ray fluorescence spectrometer. The characterization of RMs was performed using independent chemical methods as gravimetric methods, x-ray fluorescence spectrometry, optical emission spectrometer and atomic absorption...
XXI IMEKO World Congress
· TC24
· 2015
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A. A. Mikhal, Z. L. Warsza
AC impedance model of a liquid conductivity has been developed to assess the influence of magnetic vector potential. It has been proved that the field in a liquid conductor is quasi-static. Approximation error, even taken for very concentrated solutions (e.g. sea water), does not exceed 0.01 ppm. The calculation of resistance of the four-electrode cell is given with the account of Ampere's circuit law. Two types of errors are defined: DC error due to finite thickness of electrodes, and AC error due to presence of displacement currents when using an impedance model.
XXI IMEKO World Congress
· TC24
· 2015
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Alessia Demichelis, Guido Sassi, Maria Paola Sassi
Accurate VOC mixtures at ppb level are needed both for the atmospheric monitoring both for the clean room industries. Research is developing a compact diffusion generator of trace mixtures to be installed on-site. To assure the required accuracy, vials with a low and calibrated diffusion rate DR are necessary. In this paper glass vials were realized, the uncertainty budget of DR was evaluated and experimentally validated. A DR accuracy better than 3% at 200 ng/min release rate was obtained.
XXI IMEKO World Congress
· TC24
· 2015
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Petri Österberg, Martti Heinonen, Maija Ojanen-Saloranta, Anssi Mäkynen
This article compares the performance of a microwave based moisture measurement instrument against the conventional moisture measurement reference method Loss-on-Drying (LoD). Six different biomaterials were measured at three moisture content levels with both measurement methods. After instrument calibrations, the difference and variation of the measurement results and the repeatability of the instruments for parallel samples were estimated. Good agreement between the measurement methods was achieved with careful microwave instrument calibration.
XXI IMEKO World Congress
· TC24
· 2015
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