In this study, the workability and reaction mechanism of metakaolin (MK) based geopolymer blended with rice husk ash (RHA) silica fume (SF) was investigated. The prepared samples were subjected to tests including compressive strength fluidity tests. X-ray diffraction (XRD) Scanning electron microscope (SEM) employed explore phase composition microstructure geopolymers. molecular bonding informa...

A finger sphygmomanometer was compared with a mercury column sphygmomanometer for its ability to screen for hypertension. A total of 881 patients used each machine, both in initial screening and then for monitoring. The finger sphygmomanometer had a specificity of 98.5% in routine screening as compared with 97.6% for the mercury column device. Sensitivity of the finger device was 98.2%. These f...

For traditional centrifugal capillary pressure curve measurements, a short core plug is often employed. The capillary pressure is assumed to be zero at the outflow boundary of the core. The traditional experiments are time consuming. Measurement of the full capillary pressure curve often requires 7 to10 different centrifuge speeds, thus requiring one day to several days for measurement. Differe...

POROUS STONE N.P. Avdelidis, E.T. Delegou, and A. Moropoulou 1 IRT & Materials Consultancy, Volos, Greece; 2 National Technical University of Athens, Athens, Greece Abstract: In this work, infrared thermography was employed as a monitoring technique during water capillary rise tests on a choice of porous stones in the laboratory, as well as in situ on a cleaned porous stone surface of a histori...

The internal surface area of hexagonal (soluble) primary anhydrite CaSO4 produced by dehydration of gypsum decreases by about 70 % when the anhydrite is successively subjected to rehydration and dehydration at room temperature in humid air and in vacuum respectively. In the rehydration step, the hemihydrate is formed; its dehydration yields secondary anhydrite. Additional hydration-dehydration ...

In this paper, porous ceramics were prepared by controlling the composition and sintering temperature of raw materials based on slag from steel refining operations without need for a pore-forming agent. Solid-state processing included phase transformation low-density (2.10–2.90 g/cm3) to high-density pyroxene-based (3.22–3.88 g/cm3). Phase transformations densification investigated means mercur...

The durability of consolidated highly porous limestones was tested after salt and freeze–thaw cycles. Three limestone lithotypes that were commonly used in construction the Central-European region during previous centuries selected for tests. Specimens Miocene with four different types ethyl silica-based consolidants (KSE 100, KSE 300, 300 E, HV). After consolidation, samples exposed to freeze ...