Week 2: Material Research

CONCRETE

Concrete is made out of mixing cement, sand and gravel together. The lifespan of concrete will depend on the design life, the environmental and service conditions, and preventative maintenance practices. Design life would roughly be around 50-70 years. Concrete is widely used for making architectural structures, foundations, brick/block walls, pavements, bridges/overpasses, highways, runways, parking structures, dams, pools/reservoirs, pipes, footings for gates, fences and poles and even boats. Concrete can be damaged by fire, aggregate expansion, sea water effects, bacterial corrosion, calcium leaching, physical damage and chemical damage.

GLASS

Glass is an amorphous solid material that exhibits a glass transition. Glass are typically brittle and can be optically transparent. The glass used for windows and drinking vessels are soda-line glass which are made out of 75% Silicon dioxide, sodium oxide from soda ash and lime.

Glasses often corrode when they are exposed for prolonged times to moisture e.g. due to weather. Additionally, many compounds can either directly corrode the glass or act as an accelerator to the process. These compounds, such as sulfur- and nitrogen-containing compounds, can originate from air. Other compounds, such as alkalis, can leached out of concrete.  Corrosion can be often recognized by a haze or by iridescent opalescent layers on the glass.

MARBLE

Marble is a non-foliated metamorphic rock composed of re-crystallized carbonate minerals, most commonly calcite or dolomite. Marble is commonly used for sculpture and building materials.

Marble is susceptible to chemical weathering. Marble holds up better than limestone in both acid and unpolluted rainwater, but it will show signs of weathering in time. Water enters small holes in the marble at this point, worsening the weathering. This phenomenon is known as surface flaking.
Weathering is the natural breakdown of rocks into smaller particle sizes and different forms. Since marble is a metamorphic rock, the properties of marble and limestone are similar