A datum point for estimating the adsorbed water in hydrated portland cement

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Download Full-text

Calculating Portland Cement Clinker

Scientific American ◽

10.1038/scientificamerican11071908-300bsupp ◽

1908 ◽

Vol 66 (1714supp) ◽

pp. 300-300

Keyword(s):

Portland Cement ◽

Cement Clinker ◽

Portland Cement Clinker

Download Full-text

The Portland Cement Industry of the World

Scientific American ◽

10.1038/scientificamerican11051898-19108supp ◽

1898 ◽

Vol 46 (1192supp) ◽

pp. 19108-19109

Author(s):

Bernard L. Green

Keyword(s):

Portland Cement ◽

Cement Industry ◽

The World

Download Full-text

MOLECULAR HYDROGEN PRODUCTION AT RADIATION AND HETEROGENEOUS TRANSFORMATION OF WATER UNDER INFLUENCE OF GAMMA-QUANTA ON MICRO DIMENSIONAL BERYLLIUM OXIDE+ADSORBED WATER SYSTEM

Azerbaijan Chemical Journal ◽

10.32737/0005-2531-2018-2-74-79 ◽

2018 ◽

pp. 74-79

Author(s):

Y.D. Jafarov ◽

◽

N.K. Ramazanova ◽

S.R. Gadjiyeva ◽

K.T. Eyubov ◽

...

Keyword(s):

Hydrogen Production ◽

Molecular Hydrogen ◽

Water System ◽

Beryllium Oxide ◽

Adsorbed Water

Download Full-text

Development of a Capacitor Probe to Detect Subsurface Deterioration in Concrete

MRS Proceedings ◽

10.1557/proc-503-231 ◽

1997 ◽

Vol 503 ◽

Cited By ~ 2

Author(s):

B. K. Diefenderfer ◽

I. L. Al-Qadi ◽

J. J. Yoho ◽

S. M. Riad ◽

A. Loulizi

Keyword(s):

Dielectric Constant ◽

Portland Cement ◽

Electromagnetic Waves ◽

Low Cost ◽

Complex Dielectric Constant ◽

Life Cycle Costs ◽

Parallel Plates ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Set Up

ABSTRACTPortland cement concrete (PCC) structures deteriorate with age and need to be maintained or replaced. Early detection of deterioration in PCC (e.g., alkali-silica reaction, freeze/thaw damage, or chloride presence) can lead to significant reductions in maintenance costs. However, it is often too late to perform low-cost preventative maintenance by the time deterioration becomes evident. By developing techniques that would enable civil engineers to evaluate PCC structures and detect deterioration at early stages (without causing further damage), optimization of life-cycle costs of the constructed facility and minimization of disturbance to the facility users can be achieved.Nondestructive evaluation (NDE) methods are potentially one of the most useful techniques ever developed for assessing constructed facilities. They are noninvasive and can be performed rapidly. Portland cement concrete can be nondestructively evaluated by electrically characterizing its complex dielectric constant. The real part of the dielectric constant depicts the velocity of electromagnetic waves in PCC. The imaginary part, termed the “loss factor,” describes the conductivity of PCC and the attenuation of electromagnetic waves.Dielectric properties of PCC have been investigated in a laboratory setting using a parallel plate capacitor operating in the frequency range of 0.1 to 40.1MIHz. This capacitor set-up consists of two horizontal-parallel plates with an adjustable separation for insertion of a dielectric specimen (PCC). While useful in research, this approach is not practical for field implementation. A new capacitor probe has been developed which consists of two plates, located within the same horizontal plane, for placement upon the specimen to be tested. Preliminary results show that this technique is feasible and results are promising; further testing and evaluation is currently underway.

Download Full-text