Accelerators & Retarders - North America
Concrete set accelerating and retarding admixtures allow concrete producers to modify the setting time of concrete according to their specific project needs. Accelerating and retarding admixtures can be used to modify concrete set acceleration or retardation. Ideal for stabilization of long haul concrete. Allows for more uniform and predictable
The Role of Chemical Admixtures in the Formulation of Modern
Chemical admixtures constitute indispensable ingredients for the production of modern advanced concrete. In developed countries, at least 80% of the concrete produced contains one or several admixtures. They include plasticizers, superplasticizers, retarders, accelerators, stabilizers, defoamers, foamers and shrinkage reducers, to name the most
Why Add Accelerating Admixtures to Concrete - Concrete Decor
Like water reducers, retarders and plasticizers, accelerators are one of the most popular kinds of chemical admixtures, added to a concrete batch either immediately before or during mixing. Accelerators make concrete set faster, also known as increasing the rate of hydration.
Chemical Admixtures - Cement
Retarding admixtures, which slow the setting rate of concrete, are used to counteract the accelerating effect of hot weather on concrete setting. High temperatures often cause an increased rate of hardening which makes placing and finishing difficult. Retarders keep concrete workable during placement and delay the initial set of concrete.
Retarding Admixture - an overview | ScienceDirect Topics
These admixtures, when added, would delay the setting time of the cement, i.e. the setting times lengthen. Retarders reduce the solubility of the hydrating components in cement and so are solubility reducers. Gypsum retards the dissolution of the aluminate phase (C 3 A). This retards the set of the cement.
- Do superplasticizers & retarders increase workability and setting time of concrete?
- Superplasticizers (SP) and retarders are important to enhance the workability and setting time of concrete under hot weather, hence, an experimental investigation was conducted to determine the optimum dosage for the admixtures and to study the effect of over dosage of the mentioned admixtures.
- What are accelerating admixtures?
- Accelerators: An admixture which, when added to concrete, mortar, or grout, increases the rate of hydration of hydraulic cement, shortens the time of set in concrete, or increases the rate of hardening or strength development. Accelerating admixtures can be divided into groups based on their performance and application:
- What is water reducing admixture & superplasticizer?
- As one of the concrete admixtures, water reducing admixtures and superplasticizers are usually used to reduce the mixing water volume and improve the performance of the harden concrete while maintaining better workability of the fresh concrete.
- Can water reducing admixtures and superplasticizers be used in reinforced concrete?
- Water absorption, frost resistance and permeability resistance of the concrete are mainly reviewed to discuss this influence on the durability properties of the concrete. Then, some suggestions on the application of the water reducing admixtures and superplasticizers in reinforced concrete structures and projects are proposed.
- What are water reducers & retarders?
- Water reducers, retarders, and superplasticizers are admixtures for concrete, which are added in order to reduce the water content in a mixture or to slow the setting rate of the concrete while retaining the flowing properties of a concrete mixture.
- Can retarding admixtures improve concrete workability?
- The results showed that concrete maintained proper workability for a period of more than 5 hours after using the additional dose of retarding admixtures. The additional dose of retarding admixtures not only delayed the concrete setting but also improved the compressive strength of the concrete.
