Influence of superplasticizers on the rheology and stability
The influence of superplasticizers on the rheological properties and dynamic stability of cement and reference limestone pastes were examined at room temperature. The pastes were initially formulated to exhibit nearly identical rheological parameters and bleeding–segregation characteristics, with w/c = 0.50 for the limestone and 0.55 for the
Thermal Stability of HPEG-Type Polycarboxylate Superplasticizers
The comprehensive analysis of superplasticizers has proven their quite high thermal stability. During heating up to 250°С and thermal degradation of polycarboxylate ethers, there is no emission of explosive and toxic gases. ALSO AVAILABLE IN: New and Archived Symposium Volumes - Digital Subscription
Effects of superplasticizers on the stability and morphology
The stability of hydration products of C 3 A with gypsum was investigated. The changes of ettringite crystallization were investigated by XRD and SEM. The bonding state was investigated via XPS. The changes of stabilities of ettringite vary in the presence of superplasticizers because of the formation of morphologies.
Al-Neshawy, Fahim; Punkki, Jouni Stability of air-entrainment
and superplasticizers after 5 and 60 min [6]. 2. LABORATORY TESTING As a part of Robust Air-project at Aalto University, concrete tests with different types of AEAs and PCE- superplasticizers are carried out and the stability of entrained air is investigated. The aim of the project is to clarify the factors affecting the stability of the air
Superplasticizer: Types, Advantages & Disadvantages
1. Superplasticizers reduces the water content. 2. It reduces the cement content. 3. Also, increases the workability of concrete. 4. It reduces the permeability of concrete. 5. They are easy to placement. 6. Increased long terms. 7. It develops the early strength. Disadvantages of Superplasticizer: 1.
- Are superplasticizers essential components of modern concrete?
- Conclusions Superplasticizers are essential components of modern concrete, allowing the production of highly durable structures with reduced environmental impact. Their working mechanisms rely on their molecular structures and physical–chemical interactions taking place between them and the surface of cement particles.
- Which superplasticizer admixture is better?
- Based on the findings, out of three superplasticizers, PC—based admixture showed a better improvement in strength aspects compared to other mix. Compressive strength of UHPC (a) SNF admixture (b) SMF admixture (c) PC admixture
- What is a superplasticizer used for?
- Superplasticizers are used to increase the fluidity of concrete without adding excess water. These molecules physically separate the cement particles by opposing their attractive forces with steric and/or electrostatic forces, as explained in Chapter 11 (Gelardi and Flatt, 2016). As a result, the concrete is easier to place.
- What is the maximum tensile strength of a superplasticizer?
- The maximum split tensile strength at 28 days of testing for all cases was found to be 29.09 MPa—SNF based, 30.72 MPa—SMF based, and 31.23 MPa—PC-based admixture, respectively, at 1.5% of dosage (Fig. 6). Therefore, the effect of superplasticizers mainly influences the workability of concrete rather mechanical properties.
- What are the effects of superplasticizers on ettringite?
- Ettringite is the main hydration product of aluminate minerals. The effects of superplasticizers on the morphology and stability of ettringite are related to the thermal stability of self-stressing cement, as well as fluidity, setting time, strength development, and durability of concrete , .
- How do superplasticizers affect the workability of concrete?
- Superplasticizers directly influence the workability of concrete, and certain factors are considered such as type of admixture, time of addition, addition sequence, mixing time, dosage, w/b ratio, and amount/nature of binder. The dosage between 0.6 to 2% by weight of cement resulted in minimal retardation.
