Site hosted by Build your free website today!

Construction deterioration & building durability glossary

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

Sandstones usually can be identified by their coarse, granular, sandy texture. They are sedimentary rocks that consist of consolidated sand grains (mainly quartz and feldspar) cemented together with a variety of minerals (silicates, iron oxides, limonite, calcite and clays). These cementing materials make one sandstone behave very differently from another. Sandstones containing silica are quite hard, strong and decay resistant, whereas those containing calcite resemble limestone in their susceptibility to acid damage, and those containing clay absorb water and deteriorate more easily. Because they have a granular texture throughout, sandstone surfaces stay matte even when worked. Most sandstones have a tendency to absorb moisture and do not withstand frost action well, so they should not be used as foundation stones and should be protected from excessive moisture.

(Reg U.S. Pat Off., SCPI (BIA)): Structural Clay Research (trademark Of the Structural Clay Products Institute, BIA). "SCR acoustile" (Reg U.S. Pat Off., SCPI (BIA) Pat. No 3,001,6O2): A side-construction two-celled facing tile, having a perforated face backed with glass wool for acoustical purposes.
"SCR brick" (Reg U.S. Pat Off., SCPI (BIA)): Brick whose nominal dimensions are 6 by 2 2/3 by 12 in. (Reg U.S. Pat Off., SCPI (BIA)):
"SCR building panel" (Reg U S. Pat Off., SCPI (BIA) Pat. No. 3,248,836): Prefabricated, structural ceramic panels, approximately 2 1/2 in. thick.
"SCR insulated cavity wall" (Reg U.S. Pat Off., SCPI (BIA)): Any cavity wall containing insulation which meets rigid criteria established by the Structural Clay Products Institute (BIA).
"SCR masonry process" (Reg. U.S. Pat Off., SCPI (BIA)): A construction aid providing greater efficiency, better workmanship and increased production in masonry construction. It utilizes story poles, marked lines and adjustable scaffolding.

Purification stage where smaller solids settle out of partially-treated water, and microorganisms are further broken down by algae and sunlight. After secondary treatment, water is often chlorinated as a last step before it is released from the plant.

Water used by industry and households. Sewage typically contains everything from soap to solid waste, and must be purified before it can be safely returned to the ecosystem.

Clay which has been subjected to high pressures until it has hardened.

shearing strength
Capacity of an object or soil to resist shearing stresses

shelf life
The length of time that a given item can remain in a saleable condition on a supplier's shelf; this is highly relevant for most sealants as they degrade in time even when stored in sealed, unopened containers.

Vertical joints filled by shoving a brick against the next brick when it is being laid in a bed of mortar.

Function: noun
Date: 1800
1. decrease in size which may result in cracking, stresses, strain
2. if scratches or substrate imperfections have not been properly filled, they will show up as the paint shrinks into them.
3. decrease in wood dimensions due to water loss the wood cell walls. Shrinkage across the grain of wood occurs when the moisture content falls below the fiber saturation point (28-30 percent). Below the fiber saturation point, shrinkage is generally proportional to moisture content. Shrinkage is expressed as a percentage of the green wood dimensions
4. a: decrease in volume of a soil (or fill) material through the reduction of voids by mechanical compaction, superimposed loads, or natural consolidation; b: settling or reduction in volume of earthen fills, cement slurries, or concrete on setting; c: decrease in volume of clayey soil or sediment due to reduction of void volume, principally by drying.
5 cracking due to drying

shrinkage crack
A crack produced in fine-grained sediment or rock by the loss of contained water during drying or dehydration; e.g., a desiccation crack or a mud crack. AGI

shrinkage index
The numerical difference between the plastic and shrinkage limits. ASCE

Ratio of the effective height of a member to its effective thickness.

Vertical joints filled, after units are laid, by "throwing" mortar in with the edge of a trowel. (Generally, not recommended.)

A masonry unit of normal face dimensions, having a nominal 2 in. thickness.

The underside of a beam, lintel or arch.

Clay products which have been fired at low temperature ranges, producing relatively high absorptions and low compressive strengths.

A perforated wall used as a sunshade.

A stretcher set on end with face showing on the wall surface.

A small fragment removed from the face of a masonry unit by a blow or by action of the elements.

Any structure or part thereof which contains a flue or flues for the discharge of gases.

A marked pole for measuring masonry coursing during construction.

A masonry unit laid with its greatest dimension horizontal and its face parallel to the wall face.

The procedure of spreading enough mortar on a bed to lay several masonry units.

Any mortar joint which has been finished with a trowel.

See Initial Rate of Absorption.

Sound Transmission Control

Stack effect
results from the difference in air temperature between indoor and outdoor air during the heating season. Warm air, being lighter than cold air, rises in a building, creating a suction at the base and exerting an outward pressure at the top. The higher the building, the greater the pressure difference across the walls and roof. The suction is greatest at the base, decreasing as the building rises to a neutral pressure plane somewhere between the ground floor and the roof. Above the neutral pressure plane the pressure becomes positive (active outwards) and increases with height, reaching its highest value at the roof. The quantity of air entering the building below the neutral pressure plane is equal to the quantity of air leaving the building above that level

Structural Integrity
The component must itself be capable of resisting the imposed load or must be supported by one that can. It must be capable of resisting the strongest loads or combinations acting directly or indirectly on it without rupturing or detaching itself away from its supported and supporting elements, or fail in creep. The component must be sufficiently rigid to resist displacement.

Back to glossary index.

Back to Environmental loads and construction degradation article.