Initial Evaluation of White Thermal Control Paints Incorporating Lithium Silicate Chemistry

For a concrete pavement, the permeation specifications for the surface have a crucial influence on its durability. In this accelerated laboratory research, a surface treatment that combines lithium silicate chemistry with a reactive silicon catalyst was tested to typify the product longevity under traffic and against salt scaling. River gravel and limestone aggregates were used in two different mixture designs. Abrasion testing was conducted according to ASTM standards in which mass loss was recorded at different time intervals. A modification was employed using a diluted deicer simulated by 4 wt.% CaCl2 solution during 15 cycles of freeze/thaw testing. A model was proposed to relate the abrasion efficiency against load cycles of a treated surface to represent the longevity of a concrete pavement. Based on the abrasion coefficient and the texture wavelength of the pavement, it is shown that the life cycle under abrasion of a concrete pavement can be modeled. During the experimental procedures, the untreated concrete specimens were used as the control sample. Results from the abrasion and freeze/thaw testing of treated specimens indicated a lower level of cumulative loss damage, which confirms the benefits of using such products to extend the service life of a concrete pavement surface. The results of modeling indicated an increase of 14% of the ultimate load application to failure for the treated specimens, which indicates an increase in longevity of the pavement. Moreover, when exposed to freeze/thaw cycles, a limestone concrete showed less damage compared with the river gravel concrete mixture.

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Scanning-probe microscope analysis of optical thin films: A new analytical tool in a manufacturing environment

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173078 ◽

1994 ◽

Vol 52 ◽

pp. 1068-1069

Author(s):

S. P. Sapers ◽

R. Clark ◽

P. Somerville

Keyword(s):

Thin Film ◽

Thin Films ◽

Thermal Control ◽

Scanning Probe Microscope ◽

Scanning Probe ◽

List Type ◽

Manufacturing Environment ◽

Physical Measurements ◽

Probe Microscope

OCLI is a leading manufacturer of thin films for optical and thermal control applications. The determination of thin film and substrate topography can be a powerful way to obtain information for deposition process design and control, and about the final thin film device properties. At OCLI we use a scanning probe microscope (SPM) in the analytical lab to obtain qualitative and quantitative data about thin film and substrate surfaces for applications in production and research and development. This manufacturing environment requires a rapid response, and a large degree of flexibility, which poses special challenges for this emerging technology. The types of information the SPM provides can be broken into three categories:(1)Imaging of surface topography for visualization purposes, especially for samples that are not SEM compatible due to size or material constraints;(2)Examination of sample surface features to make physical measurements such as surface roughness, lateral feature spacing, grain size, and surface area;(3)Determination of physical properties such as surface compliance, i.e. “hardness”, surface frictional forces, surface electrical properties.

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