What Is Plasticizer In Civil?
Plasticizer us in concrete for workability, Strength, and Durability of concrete. Plasticizer in concrete for Water-reducing admixtures usually reduces the required water content for a concrete mixture by about 5 to 12 percent.
The use of water-reducing admixtures is defining as Type A in ASTM C 494. The WRA mainly affects the fresh properties of concrete.
Which is measured by the dilution indicated in ASTM C 143-90. Water-reducing admixtures that delay the initial setting time by more than three hours. It is classified as a water-reducing admixture with a debugging effect (Type D).
Commonly used water-reducing admixtures (WRA) are lignosulfonates and hydrocarboxylic acids. The use of hydro carboxylic (HC) acids as WRA requires higher water content (w/c) compared to the lignosulfonates. Rapid bleeding is a problem for concrete treated with hydro carboxylic (HC) acids.
The increase in a slump is different according to its types and dosage. The typical dosage rate is based upon the cementitious material content (millilitres per hundred kilograms). The figure below illustrates the influence of the dosage of Lignosulfonates and HC acid on a slump.
It is shown in the figure that Hydro Carboxylic (HC) acids give a higher slump compared to lignosulfonates with the same dosage.
Water-Reducing Admixtures (WRA) has been used primarily in hot weather concrete pumping, placing, and tremie.
Careful concrete placement is required, as an initial setting time of cement will take place an hour earlier.
Another benefit of using Water-Reducing Admixtures (WRA) is that higher concrete density is achieved, which makes the concrete less permeable and has higher durability.
What Is Superplasticizer In Civil?
This Superplasticizers, also known as high range water reducers, same as a plasticizer, are chemical admixtures used where well-dispersed particle suspension is required.
Their addition to mortar or concrete allows a reduction of the water to cement ratio (W/C), not affecting the workability of the mixture, and enables the production of high-performance concrete and self-consolidating concrete.
This effect drastically improves the performance of the fresh, hardening paste. Strength of concrete increases when water to cement (W/C) ratio decreases.
Their working mechanisms lack a full understanding, revealing, into certain cases, cement-superplasticizer incompatibilities.
The addition of superplasticizer in during transit is a fairly new development within the industry.
Superplasticizer added in transit through automated slump management systems, such as Verify, allows concrete producers to maintain slump until without reducing concrete quality.
Difference Between Plasticizer And Superplasticizer in Civil
|1||To achieve a higher strength by decreasing the water-cement ratio at the same workability as an admixture free mix.||Superplasticizer by Self-leveling, Self-compacting concrete and also Penetration and compaction round dense reinforcement|
|2||To achieve the same workability by decreasing the cement content so as to reduce the heat of hydration in mass concrete.||Improved durability by removing water to reduce permeability and diffusion.|
|3||To increase the workability so as to ease placing inaccessible locations||Reduced shrinkage, especially if combined with reduced cement content.|
|4||Water reduction of more than 5% but less than 12%||Water reduction of more than 6% but less than 25%|
|5||This Plasticizer called water reducer||This Superplasticizer called high range water reducer|
|6||It is an additive used to improve the plasticity of a certain substance||It is a water-reducing admixture capable of producing large water reduction or great flammability|
|7||This increases the plasticity matricidal such as water reducer in a concrete mixture||This further increases the water requirement for concrete mixture increase the strength and durability of concrete|
|8||Add plasticizer 0.1 – 0.5 % weight of cement||Add Superplasticizer 0.5 – 3% weight of cement|