What Is Green Concrete Technology?
What Is Green Concrete Technology?
Green concrete is defined as concrete that uses waste material as at least one of its components. Its production process does not lead to environmental destruction, and it has high performance and life cycle sustainability.
Researchers have made various efforts to develop some alternatives capable of significantly reducing high energy consumption and environmental impacts during the cement fabrication process, such as implementing the concept of industrial ecology and green chemistry, as well as nanoengineering, which studies the behavior of the structure and organization of cement nanoparticles in the mix to achieve higher performance.
What Is Segregation In Concrete Technology?
Segregation in concrete is a type of particle segregation in concrete applications in which particulate solids tend to separate due to variations in particle size, density, form, and other qualities.
It is described as separating concrete aggregates (breaking apart of cohesion) in a concrete mass. It causes honeycombing, a decrease in density, and, eventually, a loss of hardened concrete strength.
The influence of aggregate segregation on the mechanical and transport behavior of concrete has been the subject of both modelings as well as experimental inquiry.
What Is Shotcrete In Concrete Technology?
Shotcrete, also called (trademark) Gunite, is concretely applied by spraying. Shotcrete is a combination of aggregate and Portland cement transported by compressed air to the nozzle of a spray cannon, where it is mixed with water.
After spraying the wet mixture in place, it may be sculpted or troweled practically immediately. Shotcrete is often placed on a framework of reinforcing bars and steel mesh for structural purposes.
Shotcrete is used for a range of decorative concrete constructions, including fake rock walls, zoo enclosures, canopy roofs, refractory linings, pools, and dams since it can assume any shape, is easily colored, and may be sculptured after application.
It is occasionally used in digging to bind the tunnel walls together to avoid leaks and fragmentation.
What Are Accelerators In Concrete Technology?
A cement accelerator is a type of additive used in concrete, mortar, rendering, and screeds. The inclusion of an accelerator shortens the setting time and hence the cure period, allowing concrete to be poured in the winter with less chance of frost damage.
Concrete is harmed if it does not reach 500 pounds per square inch (3.4 MPa) strength before freezing.
Calcium nitrate (CA(NO3)2), calcium nitrite (CA(NO2)2), calcium formate (CA(HCOO)2), and aluminum compounds are common substances utilized for acceleration nowadays.
Calcium chloride (CACl2), the most efficient and least-priced accelerator, was once widely used.
However, because chloride anions are extremely corrosive to steel reinforcement bars (rebars), their usage is no longer advised and, in many countries, illegal.
What Is NDT In Concrete Technology?
Non-destructive testing methods are used to analyze the strength of concrete as well as other features such as reinforcement corrosion, permeability, cracking, and void structure. This form of testing is essential for assessing both new and existing structures.
The primary uses for novel structures are mostly utilized to determine material quality. Existing structure testing is frequently associated with an evaluation of structural integrity.
Non-Destructive Testing Advantages
Non-destructive testing can also be used as the first step to more intrusive methods such as:
- Measuring precast, cast-in-place, or in-situ construction features
- Evaluating the suitability of the given material and components.
- Identifying and classifying cracks, cavities, honeycombing, and other flaws in a concrete structure.
- Determining the homogeneity of the concrete prior to core cutting, load testing, or other more costly or disruptive tests.
- Monitoring strength growth as it relates to formwork removal, curing cessation, and load application.
- Identifying the place, quantity, and condition of reinforcement
- Confirming or identifying suspected concrete degradation caused by variables such as overloading, fatigue, external or internal chemical assault or change, fire, explosion, or environmental impacts.
- Evaluating the probable durability of concrete while monitoring long-term property changes.
What Is ASR In Concrete Technology?
The chemical interaction between alkali cations and hydroxyl ions in the pore solution of hydrated cement paste and certain reactive silica phases found in concrete aggregates is known as the alkali-silica reaction (ASR).
The alkali-silica reaction (ASR) has the potential to be an extremely disruptive reaction in concrete.
Higher pH alkalis, such as sodium and potassium hydroxides, react with silica, generally inside aggregates, to produce a gel. This gel has a high capacity for absorbing water from the pore solution, producing concrete expansion and disturbance.
Some greywacke aggregates have been discovered to be particularly prone to ASR. The primary source of alkalis is generally Portland cement or other external sources.
