The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Konstantin Sobolev - One of the best experts on this subject based on the ideXlab platform.

  • The optimization of a gypsum-based composite material
    Cement and Concrete Research, 2002
    Co-Authors: Murat Arikan, Konstantin Sobolev
    Abstract:

    Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering include controlled setting time, good workability, sag resistance, high compressive and flexural strength, perfect bond to concrete or brick, water resistance, and improved heat and noise insulation. The application of a number of chemical Admixtures and mineral additives was found to be necessary to provide the required performance for gypsum-based materials. Among the necessary chemical Admixtures are the following: a Retarding Admixture, a water-soluble polymer (MC), an air-entraining Admixture (AE), and a superplasticizer (SP). This paper describes the effect of the different Admixtures on the consistency, setting time, and the compressive strength of GBCM. It also discusses the application of the stepwise optimization (SWO) method for the evaluation of the GBCM composition.

  • The optimization of a gypsum-based composite material
    Cement and Concrete Research, 2002
    Co-Authors: Murat Arikan, Konstantin Sobolev
    Abstract:

    Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering include controlled setting time, good workability, sag resistance, high compressive and flexural strength, perfect bond to concrete or brick, water resistance, and improved heat and noise insulation. The application of a number of chemical Admixtures and mineral additives was found to be necessary to provide the required performance for gypsum-based materials. Among the necessary chemical Admixtures are the following: a Retarding Admixture, a water-soluble polymer (MC), an air-entraining Admixture (AE), and a superplasticizer (SP). This paper describes the effect of the different Admixtures on the consistency, setting time, and the compressive strength of GBCM. It also discusses the application of the stepwise optimization (SWO) method for the evaluation of the GBCM composition. © 2002 Published by Elsevier Science Ltd.

Murat Arikan - One of the best experts on this subject based on the ideXlab platform.

  • The optimization of a gypsum-based composite material
    Cement and Concrete Research, 2002
    Co-Authors: Murat Arikan, Konstantin Sobolev
    Abstract:

    Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering include controlled setting time, good workability, sag resistance, high compressive and flexural strength, perfect bond to concrete or brick, water resistance, and improved heat and noise insulation. The application of a number of chemical Admixtures and mineral additives was found to be necessary to provide the required performance for gypsum-based materials. Among the necessary chemical Admixtures are the following: a Retarding Admixture, a water-soluble polymer (MC), an air-entraining Admixture (AE), and a superplasticizer (SP). This paper describes the effect of the different Admixtures on the consistency, setting time, and the compressive strength of GBCM. It also discusses the application of the stepwise optimization (SWO) method for the evaluation of the GBCM composition.

  • The optimization of a gypsum-based composite material
    Cement and Concrete Research, 2002
    Co-Authors: Murat Arikan, Konstantin Sobolev
    Abstract:

    Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering include controlled setting time, good workability, sag resistance, high compressive and flexural strength, perfect bond to concrete or brick, water resistance, and improved heat and noise insulation. The application of a number of chemical Admixtures and mineral additives was found to be necessary to provide the required performance for gypsum-based materials. Among the necessary chemical Admixtures are the following: a Retarding Admixture, a water-soluble polymer (MC), an air-entraining Admixture (AE), and a superplasticizer (SP). This paper describes the effect of the different Admixtures on the consistency, setting time, and the compressive strength of GBCM. It also discusses the application of the stepwise optimization (SWO) method for the evaluation of the GBCM composition. © 2002 Published by Elsevier Science Ltd.

Lukáš Kalina - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Na3PO4 on the Hydration Process of Alkali-Activated Blast Furnace Slag
    Materials, 2016
    Co-Authors: Lukáš Kalina, Vlastimil Bílek, Radoslav Novotný, Miroslava Mončeková, Jiří Másilko, Jan Koplík
    Abstract:

    In recent years, the utilization of different non-traditional cements and composites has been increasing. Alkali-activated cementitious materials, especially those based on the alkali activation of blast furnace slag, have considerable potential for utilization in the building industry. However, alkali-slag cements exhibit very rapid setting times, which are too short in some circumstances, and these materials cannot be used for some applications. Therefore, it is necessary to find a suitable Retarding Admixture. It was shown that the sodium phosphate additive has a strong effect on the heat evolution during alkali activation and effectively retards the hydration reaction of alkali-activated blast furnace slag. The aim of the work is the suggestion of a reaction mechanism of retardation mainly based on Raman and X‑ray photoelectron spectroscopy.

  • Effect of Phosphates on the Hydration Process of Alkali Activated Materials
    Materials Science Forum, 2016
    Co-Authors: Lukáš Kalina, Vlastimil Bílek, Kateřina Komosná, Radoslav Novotný, Jakub Tkacz
    Abstract:

    The study deals with the one of the important feature of alkali activated blast furnace slag which is very rapid initial setting. Therefore, the influence of the Retarding agents such as phosphates was tested. It is shown that phosphates decreases the hydration heat evolution and retards the hydration reaction of alkali activated slag effectively. The mechanism of retardation is studied through the microcalorimeter and electron microscopy equipped with energy dispersive analyzer (SEM-EDS). The optimal dosage of suitable Retarding Admixture in the means of mechanical properties has been determined.

Moses Tanimola - One of the best experts on this subject based on the ideXlab platform.

  • Effects of a Locally Sourced Water Reducing/Retarding Admixture on Concrete
    2020
    Co-Authors: Ayorinde Oladiran, Moses Tanimola
    Abstract:

    The results of experiments to determine the effects of a water reducing/Retarding Admixture locally sourced from orange tree leaves on concrete are presented in this paper. The Admixture was added to the concrete mix in percentages of 1, 2, 5, 10 and 15 by weight of cement. The results showed that the workability of the mix improved while the water cement ratio reduced gradually as the Admixture content was increased from 1% to 15%. Cube crushing tests performed showed that the 28th day compressive strengths of the concrete increased considerably as the Admixture content increased from 1% to2% up to 5% beyond that of the control. Thereafter, the compressive strengths dropped at 10% and 15% Admixture contents. The percentage increase in compressive strengths of the concrete with 1%, 2% and 5% Admixture contents were 6.58%, 14.07% and 23.53% respectively above that of the control. Ke ywords: water reducing, Retarding, Admixture, workability, crushing tests, compressive strengths

  • effects of a locally sourced water reducing Retarding Admixture on concrete
    2012
    Co-Authors: Ayorinde Oladiran, Moses Tanimola
    Abstract:

    The results of experiments to determine the effects of a water reducing/Retarding Admixture locally sourced from orange tree leaves on concrete are presented in this paper. The Admixture was added to the concrete mix in percentages of 1, 2, 5, 10 and 15 by weight of cement. The results showed that the workability of the mix improved while the water cement ratio reduced gradually as the Admixture content was increased from 1% to 15%. Cube crushing tests performed showed that the 28th day compressive strengths of the concrete increased considerably as the Admixture content increased from 1% to2% up to 5% beyond that of the control. Thereafter, the compressive strengths dropped at 10% and 15% Admixture contents. The percentage increase in compressive strengths of the concrete with 1%, 2% and 5% Admixture contents were 6.58%, 14.07% and 23.53% respectively above that of the control. Ke ywords: water reducing, Retarding, Admixture, workability, crushing tests, compressive strengths

Elena Crotti - One of the best experts on this subject based on the ideXlab platform.

  • CSA-based Portland-free binders to manufacture sustainable concretes for jointless slabs on ground
    Construction and Building Materials, 2018
    Co-Authors: Luigi Coppola, Denny Coffetti, Elena Crotti, Tommaso Pastore
    Abstract:

    Abstract The paper is aimed to the evaluation of the influence of water/binder ratio, tartaric acid dosage and curing condition on rheological, elastic and physical properties of sustainable shrinkage-compensating concretes manufactured with calcium sulphoaluminate cement (CSA), anhydrite ( C S ¯ ) and supplementary cementitious materials (SCMs)/lime (CH) compound in place of ordinary Portland cement (OPC). Results indicated that tartaric acid-based set-Retarding Admixture governs the behavior of concrete both in fresh and hardened state. In addition, according to Abram’s model, results evidenced the water/binder ratio as a key factor in strength gain. Moreover, tartaric acid allows the production of shrinkage-compensating Portland-free concretes particularly indicated for slabs on ground. Finally, by replacing OPC with SCMs and lime, it is possible to obtain, both for CO2-emissions and energy consumption, a reduction up to 60% at equal strength class respect to an OPC-based concrete.

  • Use of tartaric acid for the production of sustainable Portland-free CSA-based mortars
    Construction and Building Materials, 2018
    Co-Authors: Luigi Coppola, Denny Coffetti, Elena Crotti
    Abstract:

    Abstract The purpose of the study is to evaluate the effect of a tartaric acid-based set Retarding Admixture on rheological, elastic and physical performances of sustainable mortars manufactured with calcium sulfoaluminate, anhydrite and Supplementary Cementitious Materials replacing totally OPC. Experimental results indicated that the tartaric acid acts as superplasticizer and it is effective to extend the pot-life of mortars up to about 2 h. On the other hand, the set-Retarding Admixture provides a strong retardation of binder hydration resulting in a reduction of initial expansion and compressive strength at early ages. However, this Retarding effect disappears at long ages.