In this article, two of the visual defects that might appear on concrete are discussed: Surface Rust Stains and Efflorescence (or Leaching) of concrete. Surface Rust Stains Rust stains are caused by corroded steel below the surface which has inadequate cover, or by corroded steel that is fully exposed due to a spall or poor …
In this article, two of the visual defects that might appear on concrete are discussed: Cracking and Honeycombing of concrete. Cracking of Concrete Cracking is frequently occur in concrete structures. There are various types of cracking that may occur. Cracks are caused by numerous diverse reasons and can be detected by a Visual Analysis. It should be …
In this article, two of the visual defects that might appear on concrete are discussed: Surface Scaling and Spalling of concrete. Surface Scaling of Concrete Scaling is a form of disintegration and is due in most part to freeze–thaw reactions which cause the concrete to flake or peel off at the exposed surface. Scaling is indicative of …
Effect of Elevated Temperature on Concrete Strength Concrete structures could be exposed to high temperatures due to different reasons, mainly during exposure to fire; another one could be when the structure or its elements are a part of industrial installations. At high temperatures, Portland cement concretes undergo important changes in their properties, due to formation …
Fiber Reinforced Plastics (FRP):Introduction-Properties Concrete structures regardless of their purpose are disintegrating. A common link for this breakdown is that steel reinforcement is being used to strengthen the flexural capacity of the structures. Reinforcing steel will corrode when contact is made with humid or salty environments. When steel corrodes, it is expanding which creates tensile …
In this article, the damage caused by freezing and thawing cycles to concrete is described. Freezing-thawing damage results from the fact that when water freezes to ice, it expands by about 9 percent. When the water in concrete freezes it produces pressure in the pores of the concrete. If the developed pressure exceeds the tensile strength of …
The concept of water-to-cement ratio (w/c) of concrete is a universally fundamental concept and is considered as the oldest law in the concrete technology. The water/cement ratio influences the durability properties of concrete in a significant way. Decreasing the w/c value would lead to a reduction in concrete porosity and accordingly, lower permeability and higher …
Corrosion of steel in concrete may cause structural damage and early failure of Reinforced Concrete structures. Besides the volume increase and cover spalling due to corrosion (Figure 1), it negatively influences, the flexural, shear, and bond strength of the corroded element. Vidal and his colleagues studied the long-term corrosion process of reinforced concrete beams stored in …