Effect of retarding superplasticizers on the properties of cement paste, mortar and concrete (original) (raw)
Related papers
EFFECT OF TYPE AND COMPOSITION OF CHEMICAL ADMIXTURE ON PROPERTIES OF PRODUCED CONCRETE
This work aims to study the effect of different types of superplastizicer. The experiment work included test on slump flow, compressive strength, splitting and modulus of rupture. Water cement ratio and cement content were maintained constant (0.45 and 350 Kg/m3) respectively. Three different admixture (polycarboxylic ether melamine formaldehyde, and of sulphonated naphthalene) have been used. Four dosage of superplastizicer were adopted (0.5, 1, 1.5, 2 and 2.5) liters for 100 Kg of cement. Based on the experimental results, superplasticizers based on Modified polycarboxylic ether are more efficient than other superplasticizers, concerning the degree of workability, compressive strength, and flexible strength Over dosage of SP found to deteriorate the properties of concrete, signs of bleeding and segregation were noticed. However, if the dosage levels of SP are lower than the optimum dosage, increase in admixture dosage may help to enhance the concrete characteristics
EFFECT OF CHEMICAL ADMIXTURES ON PROPERTIES OF CONCRETE: A METHODOLOGICAL REVIEW
International Journal of Research and Analytical Reviews (IJRAR), 2018
As we know that concrete is a mix of cement, sand, aggregate, water and additional materials such as Admixtures and Mineral additives. In these years, government and industries emphasize on high initial strength and high quality concrete in less times. Because of these reasons researchers have been focused to bring some variations in concrete components to achieve a good quality and high strength concrete. Nowadays using of chemical Admixture become more and more because everyone and every industry want to have a good quality and high strength concrete. We have different additive that we can get these factors so soon such as Mineral additives and Chemical Admixtures and in this review paper we cover Chemical Admixtures such as Plasticizer, Super Plasticizer, Retarding, Accelerating, Air Entraining and each of them has their own properties and different chemical influences on the properties of concrete like compressive strength, tensile strength, workability, water content etc.
Effect of Different Chemical Admixture on Fresh and Harden Concrete
2019
In recent decades, huge success has been achieved by using the Chemical and Mineral admixtures for concrete construction. A lot of different types of admixtures for concrete are used now adays in construction industry. The aim of this paper is to compare different type of admixture dosage for optimal use. Tests of cement’s initial setting time, consistency and compressive strength of concrete were made. Tests of cements and fresh concrete were conducted at temperature 25°C. Compressive strength was tested after 3, 7 &28 days of curing. Specimens for those tests were cured in curing vat. Examined admixtures were based on Polycarboxylate Ether (PCE) & Napthalene Formaldehyde (SNF). All of them are described as both set and hardening retarder for concrete. Admixtures +were added in maximum dosage allowed by producer. All of admixtures caused increase of initial setting time and increase of early compressive strength. The addition of super plasticizers to concrete imparts a high strengt...
Data in brief, 2018
The aim of this work is to study the influence of the admixture of superplasticizers on the physical properties of cement paste to know the initial and final time, water content and mechanical performance of concrete. In this work we have incorporated an Advanced Superplasticité for Prolonged Slump Retention (ASPPSR402) in the formulation matrix of concrete at different percentages ranging from 0.5% to 5% by weight of cement with a step of 0.5%, while partially substituting the mixing water by the last one to reduce the amount of water used. The obtained results by different prospected formulations show that the admixture of ASPPSR402 in formulations matrix significantly reduces the (Water/Cement "W/C") ratio. Subsequently, we observed that the initial and final time increases in function of the percentage of ASPPSR402. Similarly, the compressive strength at the young age, median age and long-term has been improved.
Characteristics of Concrete with Admixtures
The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2008
In recent decades, tremendous success has been achieved in the advancement of chemical admixtures for Portland cement concrete. Most efforts have centered on improving the properties of concrete with minimal investments by ready-mix suppliers and contractors in the way of specialized equipment or special skills and education of their labor forces. This approach has resulted in construction cost reductions and universally accepted ready-made remedies for unexpected problems during construction. The behavior of concrete improved with superplasticizers additives is studied.
Influence of chemical admixtures on density and slump loss of concrete
International Journal of Modern Engineering Research (IJMER)
The results of test conducted on concrete in the presence of plasticizers and super plasticizers. The objective was to observe the change in density of concrete & loss of workability under the influence of plasticizers and super plasticizers at various dosages level. The result of the treated mix was compared with the control mix (mix without admixture). Observations were made on solid phases of concrete, to note the variation in density at constant and reduce water cement ratio. From the experience and knowledge gained from this course of study both, plasticizers and superplasticizers not only improved workability at constant water cement ratio but considerably enhanced the density at reduce water-cement ratio however loss in slump observed.
Effect of admixtures on the setting times of high-strength concrete
Cement and Concrete Composites, 2000
The effect of silica fume (SF), metakaolin (MK), fly ash (FA) and ground granulated blast-furnace slag (GGBS) on the setting times of high-strength concrete has been investigated using the penetration resistance method (ASTM C 403). In addition, the effect of a shrinkage-reducing admixture (SRA) on the setting times of normal and high-strength concrete was also studied. The setting times of the high-strength concrete were generally retarded when the mineral admixtures replaced part of the cement. While the SRA was found to have negligible effect on the setting times of normal strength concrete, it exhibited a rather significant retarding effect when used in combination with superplasticiser in high-strength concrete. The inclusion of GGBS at replacement levels of 40% and greater resulted in significant retardation in setting times. In general, as replacement levels of the mineral admixtures were increased, there was greater retardation in setting times. However, for the concrete containing MK, this was only observed up to a replacement level of 10%.
Long-term performance of concrete using additives
International Journal of Microstructure and Materials Properties, 2020
The increase in global warming due to emission of greenhouse gases especially during the production of cement has become threat to the environment. The development of sustainable and economical materials has become need of the present scenario. Also, direct disposal of waste from stone industries is becoming serious issue to ecosystem and need its safe disposal. Accelerators are being used to accelerate stiffening and early age strength development of mortar/concrete. In this study, Kota stone powder (KSP) as partial substitution to cement and admixtures, i.e., calcium nitrate, triethanolamine as additives were used individually and in combination to examine their influence on strength, durability and micro-structural properties at later age. The aim of study was to check the viability of these materials in concrete under different environmental conditions; and to make sustainable concrete by reducing cement and cost. Admixtures and stone powder individually improved the properties; while, their mixture diminished concrete properties.
Influence of Chemical Admixtures on Fresh and Hardened Properties of Prolonged Mixed Concrete
Advances in Materials Science and Engineering
Effects of different chemical admixtures on fresh and hardened properties of prolonged mixed concrete and their cost-effectiveness were investigated. Influence of sand to aggregate volume ratio, cement content, and use of chilled mixing water on the properties of prolonged mixed concrete was studied as well. Different concrete mixtures were prepared using five different types of chemical admixture (one water reducer based on lignosulfonate and four superplasticizers based on sulfonated naphthalene polymer, polycarboxylic ether, second-generation polycarboxylic ether polymer, and organic polymer), varying s/a ratio (0.40 and 0.45) and cement content (340 kg/m3 and 380 kg/m3) and using chilled mixing water. Slump tests were performed at 15-minute intervals to assess the fresh performance of each prolonged mixed concrete mixture. 100 mm by 200 mm cylindrical concrete specimens were prepared and tested for compressive strength, Young’s modulus, splitting tensile strength, and ultrasonic...