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Construction deterioration & building durability glossary


Article & glossary hosted by A. Sebastian Engineering and Investigation Services

EBM
See Engineered Brick Masonry.

ECCENTRICITY
The normal distance between the centroidal axis of a member and the parallel resultant load.
e1/e2: Ratio of virtual eccentricities occurring at the ends of a column or wall under design. The absolute value is always less than or equal to 1.0.

EFFECTIVE HEIGHT
The height of a member to be assumed for calculating the slenderness ratio.

EFFECTIVE THICKNESS
The thickness of a member to be assumed for calculating the slenderness ratio.

EFFLORESCENCE
A powder or stain sometimes found on the surface of masonry, Because mortar must be wet to render it plastic for bricklaying, brickwork becomes damp in the course of construction. As it subsequently dries, the moisture, in which the various salts derived from mortar and bricks have been dissolved, moves to the wall surface to evaporate, leaving a deposit of salts, usually as a white coating on the bricks resulting from deposition of water-soluble salts.

electromagnetic vulnerability
The characteristics of a system that cause it to suffer a definite degradation (incapability to perform the designated mission) as a result of having been subjected to a certain level of electromagnetic effects. Also called EMV

empowerment
Act by which an employee, contractor or consultant is given the necessary freedom to make full use of his knowledge, energies and judgement to provide better service. It necessarily involves freedom of and responsibility for decision-making.
FR "habilitation", fem. noun; "empouvoirement" being a term to be avoided

engineered brick masonry
Masonry which is designed by structural analysis methods.

Engineered wood
Relatively new term that means just what it says: wood products that are engineered. Plywood is considered to be the original engineered wood product and has been used for structural applications since the 1940s. Since then, other products have been developed which fit into the engineered wood family: glulam, OSB, and wood I-joists are some that are represented by APA and EWS.
Glued engineered wood products, including plywood, oriented strand board (OSB), glued laminated timber (glulam), wood I-joists and structural composite lumber, are manufactured by bonding together wood strands, veneers, lumber or other wood fiber to form a larger, more efficient composite structural unit. These products are extremely resource efficient because they utilize more of the available resource with minimal waste. In addition, in many cases, they are produced using faster growing and often underutilized wood species from managed forests and tree farms, thus reducing the industry's reliance on so-called "old growth" forests.
At the same time, glued engineered wood products meet marketplace needs for products with superior and consistent performance characteristics. For example, glulam beams and wood I-joists, "engineered" to exacting standards, can carry greater loads over longer spans than is possible with an equivalent size of solid sawn wood.

What is engineered wood?

Definitions vary, but engineered wood is generally understood to include a wide range of products manufactured by bonding together wood strands, veneers, lumber or other forms of wood fiber to produce a larger and integral composite unit.

Structural engineered wood products are "engineered" by virtue of possessing design values that are confirmed by methods other than simple visual grading.

APA divides structural engineered wood products into four general categories: 1) wood structural panels, including plywood, oriented strand board, and composite panels; 2) glued laminated timber (glulam); 3) structural composite lumber (SCL), including primarily laminated veneer lumber (LVL) but also parallel strand lumber and oriented strand lumber; and 4) wood I-joists.

A number of factors have contributed to what is emerging as a new era for engineered wood products, including changing resource supplies, manufacturing innovations, environmental considerations, superior performance, and industry standardization. All of these considerations suggest that engineered wood products will occupy an increasingly important place in the building materials market of the future.

environmental services
Various combinations of scientific, technical, and advisory activities (including modification processes, i.e., the influence of manmade and natural factors) required to acquire, produce, and supply information on the past, present, and future states of space, atmospheric, oceanographic, and terrestrial surroundings for use in planning and decisionmaking processes, or to modify those surroundings.

ex·po·sure/ik-'spO-zh&r/
Function: noun
Date: 17th century
The condition of being unprotected, especially from severe weather or generally, the condition of being subject to some effect or influence.


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