Compatibility Assessment of Commercial Cements with superplasticizers (original) (raw)
Related papers
2020
Concrete is the most common building material that is used prominently in construction industry. It can be cast in any desired shape and fashion and should be workable whether on-site or in ready mix concrete production. To achieve better performance and desired proprieties of concrete, the use of chemical admixtures is priceless choice in concrete production. While, there are common problems facing to optimize superplasticzer dosage with various types of cement to produce desirable properties of fresh and hardened concrete due to lack of practices in construction industry in our country. The purpose of this research was determining optimum Superplasticizer dosage for desired workability using Marsh Cone Test at predetermined water cement ratio. It was also analysis the effect and influences of Superplasticizer dosage on concrete properties. Slump Cone test and testing machine were used to determine such properties of concrete. The first conclusion that was drawn from the research was deciding optimum dosage on cement slurry which was prepared using different types of Super plasticizer and Cements for variable water cement ratio. Secondly, the test were carried out to see effects of Superplasticizer dosage on improvement of workability and flowablity of fresh concrete in specified doses. Also, it was also noticed changes of hardened concrete properties using mechanical tests. Using 0.45 and 0.40 water-cement ratio, optimum dosage of Superplasticizer (ODS) has found out, with respect to different Superplasticzers on different brand of cement paste mix. Secondly, it also observed the effect of superplasticzer dosage for predetermined quantity (0.5%, 1.0%, 1.5% and 2.0%) on hardened concrete strength in addition to fresh concrete characteristics. Thirdly, the demand of water reduced by 20%, 23%, 27% and 30% from total mix water using 0.5%,1.0%,1.5% and 2.0% of Superplasticizer respectively in concrete mix. Generally, Superplasticzer is playing vitally role to achieve better physical properties and quality of concrete, and resolving challenges in undesirable conditions during concrete work operations. Despite these facts, over dosage of SP were found to deteriorate the properties of concrete with indication of lower compressive strength and higher porosity due to bleeding and segregation occurrences.
Effect of Superplasticizer Dosage on Workability and Strength Characteristics of Concrete
The use of chemical admixtures in concrete is a common solution to achieve full compaction particularly where reinforcement congestion and shortage of skilled workers. The past researchers have been underscored the use of chemical admixtures imparts the desirable properties to concrete in both fresh and hardened state. This paper has been made an attempt to study the influence of superplasticizer dose of 400ml, 600ml, 800ml, 1000ml and 1200ml/100 kg of cement on performance of Concrete. The experimental tests for fresh and hardened properties of concrete for three mixes of 30 MPa grade are studied and the results are compared with normal concrete. The tests considered for study are, slump test, slump loss, flow table and compressive strength test The results show that for the constant water cement ratio, increase of superplasticizer dose in properties of concrete leads to gain of good workability. Moreover, there is also increase in compressive strength than that of normal concrete mix.
The adverse effects of elevated temperatures on the properties of the fresh concrete include increased water demand, shorter setting time and increased slump loss. Superplasticizer (SP) is important to enhance the workability and setting time of concrete under hot weather, hence, an experimental investigation was conducted to determine the effect of dosage of the mentioned admixture. Concrete mixes with SP dosages of 400, 600, 800, 1000 and 1200 ml/100kg of cement were prepared, together with two control mixes (water/cement ratio were 0.56 and 0.66 respectively). After casting, normal curing was carried out on the concrete samples. Properties such as compressive strength, porosity, water absorption, permeability and initial surface absorption were determined, besides determining the workability and setting time of the fresh concrete. Over dosage of SP were found to deteriorate the properties of concrete with indication of lower compressive strength and higher porosity. However, if the dosage levels are lower than the optimum dosage, increase in admixture dosage might help to enhance the concrete characteristics.
STUDIES ON COMPATIBILITY ISSUES OF SUPER PLASTICIZERS WITH OPC 53-S CEMENT
International Journal of Technical Innovation in Modern Engineering & Science (IJTIMES), 2019
The behaviour of the high performance concrete in fresh state can be calculated with the flow behaviour of cement paste made with required dosage of High Range Water Reducer (Super Plasticizer). To know the flow behaviour, Compatibility studies are to be done. This Paper deals with the Compatibility issues between different types of Super Plasticizer coming under PCE and SNF groups with OPC 53-S cement. The Compatibility between Super Plasticizer and OPC 53-S cement can be known by conducting three different types of tests. Flow test, Mini Slump test and Penetration tests are conducted and Compatibility studies are done. From flow test and mini slump test, the flow behaviour of the super plasticizer can be observed. And from the penetration test, the setting time of super plasticizer can be obtained. All the tests conducted above are conducted with varying w/c ratio i.e. 0.35 w/c and 0.40 w/c. The test results also show the variation of the curves with two different w/c ratios. This Paper also mentions the optimum dosage of PCE based Super Plasticizer is 0.9% with respect to the weight of the cement and SNF based Super Plasticizer is 1.0% with respect to weight ofcement.
EFFECTS OF CHEMICALS AS SUPERPLASTICIZER ON VARIOUS PROPERTIES OF THE CONCRETE
International Journal of Creative Research Thoughts (IJCRT), 2020
The second most consumed material on earth is concrete, after water. So we need to look for ways to reduce the use of water in concrete in most economic way possible. We also want concrete to gain its ultimate strength earlier to reduce the overall requirement of water. Plasticizers and Superplasticizers are used to reduce the water requirement in the concrete. The use of these admixtures not only reduces the water content of the concrete but also gives higher early strengths and higher ultimate strengths. The available Plasticizers and Superplasticizers in the market are costly and hence cannot be used for smaller project as they will make the project uneconomical. This project work is conducted to find better alternatives to these available costly Superplasticizers. This report is about the project work which includes the study of effect of chemicals as Superplasticizers on various properties of the concrete. The study of different chemicals used as Superplasticizers for concrete and their comparison with the normal concrete. There are two different chemicals taken for the project work. The chemicals are added in different proportions of 0.25%, 0.5%, 0.75% and 1% of the weight of cement. The concrete cubes of M25 grade were prepared. The normal cubes and the cubes with the chemical admixture were tested. Then the behavior of the concrete is noticed to checks how the changes made in the properties with the addition of the different proportion of the chemicals. The reduction in water content is also checked with the addition of the different proportion of the chemical admixtures. The properties like consistency, initial setting time, slump cone test, water absorption test and compressive strength tests were tested. The project work also include the study of the properties of the chemicals used for the project work .It comprises of different tests for different building material such as sand, aggregates (coarse & fine aggregates), concrete and cement used for the completion of the project. The aim of the project is to find a better substitute to the costly super plasticizers available in the market and make the each project economical.
Superplasticizer compatibility with cement properties -A study
, Materials Today: Proceedings, 2022
Portland cement has been the conventional building material down through the ages. But with passing decades materials other than cement were being added to the cementitious system from outside to improve or modify its mix properties. The role of these materials was of varying degrees starting from water reducing to viscosity modifying to shrinkage reducing to being pozzolanic to reducers or accelerators. The existing literature survey suggests that a very high range water reducer or Superplasticizers can make a cementitious mix flowable at a low water-cement ratio without segregation and bleeding-the most basic principle of a fresh cementitious mix. Portland cement without admixtures in contact with water tends to flocculate resulting in agglomeration of particles in the mix thus making the system non-lubricating. Our paper discusses the various effects of Superplasticizers on the properties of cementitious mixes and the contribution of its constituent mineral phases. More recently, a new type of Superplasticizers based on 4th generation polymers are preferred in terms of lower slump loss at a low water-cement ratio. Our paper reports the addition of high performing superplasticizer-Poly Carboxylate Ether in cement composites as per Indian Standards has resulted in a denser cementitious matrix and higher strength gain at longer terms compared to normal superplasticizers.
Strength and Workability Characteristics of Concrete by Using Different Super Plasticizers
International Journal of Materials Engineering, 2012
Concrete, a composite material made with cement, aggregates, admixtures or super plasticizers and water comprises in quantity the largest of all man-made materials. Although aggregates make up three fourths of the volume of concrete, the active constituent of concrete is cement paste. The properties and performance of concrete are largely determined by the properties of the cement paste. Super plasticizers in concrete confer some beneficial effects such as acceleration, retardation, air entrainment, water reduction, plasticity etc., and these effects are due to their action on cement. The scientists are mainly concentrating to develop the specialized concretes, to enhance the service life of the buildings, and to provide satisfactory performance under aggressive environments. In the present experimental investigation M 30 concrete is used as control mixture with four different super plasticizers namely SNP (Sulphonated Naphthalene Polymer) 1, SNP 2, SNP 3 and SNP 4. Strength of modified concrete is compared with the normal concrete i.e. without super plasticizer. The results show that the significant improvement in the strength and workability of modified concrete.
Influence of Superplasticizer on Strength of Concrete
This paper outlines an experimental study that measures the effects of superplasticizer admixture on proprieties of concrete. However, Superplasticizers are the most important admixtures enhancing concrete performance. The development of new superplasticizers during the last decades has determined the most important progress in the field of concrete structures. 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. Concrete mixes with SP dosages of 600, 800, 1000 and 1200 ml/100kg of cement were prepared, together with one control mixes. After casting, normal curing was carried out on the concrete samples. Properties such as compressive strength were determined, besides determining the workability of the fresh concrete. However, compressive strength is improved by dosage 1.0 % of SP after 28 days curing is 55 N/mm 2 , which is higher than that of control concrete, the optimum amount of admixture must be 1 %. Over dosage of SP found to deteriorate the properties of concrete with indication of lower compressive strength. However, if the dosage levels are lower than the optimum dosage, increase in admixture dosage might help to enhance the concrete characteristics.
Compatibility of superplasticizers with different cements
Construction and Building materials, 2000
The incompatibility between cement and chemical admixtures has increased over the last decade. Specifications calling for the use of admixtures in concrete often results in strange occurrences, i.e. rapid set, retardation, accelerated stiffening, etc. This paper presents the observations of a study on the effect of different superplasticizers with respect to the setting behavior and Ž . compressive strength. The hydration behavior of different cements at different time intervals 1, 3, 7, 28 and 360 days in the Ž . presence of superplasticizers has also been analyzed by differential thermal analysis DTA . The 33 grade ordinary Portland Ž . cement has shown retardation with naphthalene-based superplasticizer at the recommended dose 2% of manufacturer, where as 43 grade OPC has shown retardation with blended polymer-based superplasticizer. Portland Slag Cement and 53 grade OPC has been found to be compatible with all the superplasticizers studied in the present investigation. ᮊ