Another wall that crumbled--methadone maintenance treatment in Germany

R G Newman1

  • 1Beth Israel Medical Center, New York, New York 10003, USA.

Related Concept Videos

Brick Masonry01:12

Brick Masonry

Brick masonry uses bricks as the building blocks and involves building walls from individual bricks laid in mortar. The basic building block of brick masonry is the wythe, a vertical layer of bricks with a thickness of one brick. Within a wythe, bricks can be laid in various courses or patterns, with the most common being the stretcher course, where bricks are laid with their long edge horizontal and face parallel to the wall.
For thicker walls, multiple wythes are bonded together using...
Composite Masonry Walls01:18

Composite Masonry Walls

Composite masonry walls combine multiple wythes of the same or different masonry materials to create a unified structure. These walls feature wythes that are bonded together either through mortar-filled collar joints, grouted spaces, or more commonly, with rigid metal ties and reinforcements, with the use of masonry header units being rare. Metal ties are preferred because they effectively minimize water penetration, as these walls primarily absorb moisture and then release it into the...
Masonry Cavity Walls01:26

Masonry Cavity Walls

Cavity walls feature a hollow space between the outer and inner wythes, connected only by corrosion-resistant metal ties. When water seeps through the outer wythe, it descends within this cavity, intercepted by flashing and eventually exiting through weep holes. To enhance moisture resistance, the inner wythe's cavity side often receives damp-proofing, doubling as an air barrier. The cavity can also house insulation to mitigate heat transfer.
Maintaining a clean cavity during construction is...
Masonry Curtain Walls01:20

Masonry Curtain Walls

Masonry curtain walls employ brick or stone veneers supported by the building's structure to form an external cladding system that is both aesthetically appealing and functional. These walls are erected through two principal techniques, first by traditional layering of masonry units and second by using prefabricated panels. Traditional construction relies on steel shelf angles attached to the spandrel beam for support, with high-bond mortars ensuring secure attachment of masonry veneer units.
Expansion and Contraction in Masonry Walls01:19

Expansion and Contraction in Masonry Walls

Masonry walls are subject to slight expansion and contraction due to variations in temperature and moisture. Thermal movement in masonry is relatively straightforward to measure and plan for. On the other hand, moisture movement poses more of a challenge. New clay masonry units typically absorb water and expand over time under normal environmental conditions. Conversely, new concrete masonry units tend to shrink as they lose the excess moisture acquired during their production process.
To...
Mortar Joint Deterioration in Masonry01:13

Mortar Joint Deterioration in Masonry

Mortar joint deterioration is a significant concern in masonry structures, with water accumulation in the joints leading to damage from freeze-thaw cycles. The repeated expansion of water during freezing and its melting during thawing develop and propagate cracks in the masonry joints. Eventually, this leads to the spalling of mortar from the joints, loosening masonry units and weakening the structure. The deteriorated mortar joints are also vulnerable to moisture intrusion into the walls.
The...