Superplasticizers | Sika Hong Kong
SikaPlast 18 - Multi-purpose superplasticizing and set retarding admixture Sika ViscoCrete-860NT - Superplasticizer for low to mid-range concrete admixture Sika ViscoCrete 1000NT - Superplasticizer and workability enhancing admixture Sika ViscoCrete 3390-Superplasticizer with retarder for mid to high-range concrete admixture
Sika Retarder-22 | Concrete Admixture
Sika Retarder-22 is a phosphate based liquid admixture that slows the cement hydration; delaying the initial set in direct proportion to the dosage used. After the planned delay in initial set, hardening develops at an accelerated rate. Suitable for use in tropical and hot climatic conditions. Safety: Sika Retarder-22 merely retards and
Retarding Admixture - an overview | ScienceDirect Topics
These admixtures influence both the dispersion of the cement in the presence of water, and the hydration rate of single cement phases, becoming the most used water-reducing/ retarding admixtures in the concrete industry (Danner et al., 2015). The source of the admixture is lignin, a biopolymer contained at 20–30 wt% in wood (Plank, 2004).
Use of Water Reducers, Retarders, and Superplasticizer
The use of WRA is defined as Type A in ASTM C 494. WRA affects mainly the fresh properties of concrete by reducing the amount of water used by 5% to 12% while maintaining a certain level of consistency, measured by the slump as prescribed in ASTM C 143-90. The use of WRA may accelerate or retard the initial setting time of concrete.
15 Types of Admixtures Used in Concrete - The Constructor
Commonly used retarding admixture is calcium sulphate or gypsum. Starch, cellulose products, common sugar, salts of acids are some other retarders. Most of water reducing admixtures are also acts as retarding admixtures and they are called as retarding plasticizers. Fig 2: Retarding Admixture (Gypsum) 3. Accelerating Admixtures
- 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.
- Can super plasticizer and retarder improve concrete workability?
- Alsadey (2013) investigated the effects of super plasticizer and retarder on the properties of concrete with a specific strength of 30 MPa. The results showed that the workability of concrete could be improved by adding a super plasticizer and a retarder. ... ...
- Can retardant admixtures be used on ready-mix concrete?
- The additional dose of retarding admixtures not only delayed the concrete setting but also improved the compressive strength of the concrete. This implies that the use of an additional dose of retardant admixtures specifically tailored for ready-mix concrete is an effective option to avoid the return of ready-mixed fresh concrete. ...
- What is the consumption of plasticizers in ready-mixed concrete?
- Consumption of plasticizers, when they are added to ready-mixed concrete depends on the workability of the concrete when it arrives at the work site, and on its desired final workability.
- 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.
