This is the updated description for what used to be known as ‘high-alumina cement’ or HAC. The problem with this cement is that it is subject to what is known as ‘conversion’. This is an additional chemical change (following the initial hydrates formation) in the calcium alumino-hydrates, promoted under conditions of high humidity and temperature.
Non destructive testing of concrete can be defined as the test method used to examine the properties of concrete used in the actual structure. These test methods can also be said as in-situ tests or in-place tests. Traditionally these tests are said to be as the non-destructive test although some minor damage to the structure may be involved. An important feature of non-destructive test is that the place where test is done can be used for re-testing.
Workability is one of the physical parameters of concrete which affects the strength and durability as well as the cost of labor and appearance of the finished product.
The property of fresh concrete which is indicated by the amount of useful internal work required to fully compact the concrete without bleeding or segregation in the finished product.
Curing is a procedure that is adopted to promote the hardening of concrete under conditions of humidity and temperature which are conducive to the progressive and proper setting of the constituent cement.
Curing has a major influence on the properties of hardened concrete such as durability, strength, water-tightness...
Strength can be defined as ability to resist change. One of the most valuable properties of the concrete is its strength. Strength is most important parameter that gives the picture of overall quality of concrete. Strength of concrete usually directly related to cement paste.
Many factors influence the rate at which the strength of concrete increases after mixing.
Cement can be defined as the bonding material having cohesive & adhesive properties which makes it capable to unite the different construction materials and form the compacted assembly.
Ordinary/Normal Portland cement is one of the most widely used type of Portland Cement.
- Syed Ahmad Amin Shah
- Engineering Materials
Joints fillers are the strips of some compressible material which is used to fill the expansion joints in different structure. Joint filling is an important process in many structures such as Buildings, Masonry Walls.
A concrete made from a mixture of lime, sand, and gravel is said to be as lime concrete. It was widely used before the lime was replaced by Portland cement.
When lime is mixed with water, lime slowly turns into the mineral portlandite (dense) in the reaction CaO + H2O = Ca (OH)2.
Accelerating Admixture — an admixture that causes an increase in the rate of hydration of the hydraulic cement and thus shortens the time of setting, increases the rate of strength development, or both.
ACI 207.5R-89 defines roller compacted concrete (RCC) as concrete compacted by roller compaction.
The concrete mixture in its unhardened state must support a roller while being compacted. Thus RCC differs from conventional concrete principally in its consistency requirement.
A mixture of asphalt cement, water and emulsifying agent (free flowing liquid at ordinary temperature).
When emulsified asphalt is exposed to the air alone or mixed with aggregate.....
Something that is mixed or blended from two or more ingredients or elements before being used. This term is used usually for concrete in civil engineering.
The initial application of binder to an absorbent highway surface prior to the construction of a wearing coat.
Aggregate is a granular material, such as sand, gravel, crushed stone, crushed hydraulic-cement concrete, or iron blast-furnace slag, used with a hydraulic cementing medium to produce either concrete or mortar.