تعتبر شركة Olux شركة رائدة ومتميزة على المستوى الدولي في مجال البحث والتطوير وتصنيع وبيع محطات التكسير والغربلة واسعة النطاق ومعدات الطحن الصناعية ومصانع الاستفادة.
orna o Materias Aie Science Cite this article Kadhim Z, Ibraheem A, Al-assadi M 21 Effect of Citrate Salts of i, Na and K on Some Physical Properties of rdinary Portland Ce- ment PC. J Mater Appl Sci 11: 11 Abstract The citric acid was used as a water reducer, setting time retarder and workable time extender admixture on ordinary Portland cement (OPC).
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The objectives of this study are to utilize and investigate the performance of molasses as a retarder and plasticizer for calcium sulfoaluminate (CSA) cement and examine the effects of molasses on ...
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Effect of gypsum on cement by preparing four different batches of Ordinary Portland Cement (OPC) using same quality clinker, maintaing SO3 level of cement 2 +/- 0.05 % and maintaining Blaine value ...
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cement (OPC) can be used for various application fields like rapid setting, rapid ... As retarder chemically pure citric acid (abbreviated in the figures as "Ret") was used.
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Chemical admixtures affecting these reactions to produce a delay in the process of cement paste stiffening are termed retarding admixtures or simply retarders. Hence, a retarder is added to a …
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The composite retarder consisting of 0.5 % tartaric acid and 1.0 % Na 2 CO 3 exhibited the best performance, fulfilling both the setting time and early strength requirements …
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retarder opc cement. Effects of Saccharide Set Retarders on the Hydration of, January 2010 Effects of Saccharides on Hydration of Ordinary Portland Cement and Pure Tricalcium Sili
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On the other hand, the compressive strength of concrete with a retarder is lower than that of concrete without a retarder [28]. The effects of suitable admixture dosage still need further ...
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The retarder effect of Na 2 CO 3 is attributed to the reactions between Ca 2+ dissolved from BFS and CO 3 2 ... Conversely, if the OPC concrete in Fig. 6 was used as reference, flexural strength of the AAF concrete synthesized by Diaz-Loya et …
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In this study, the early strength development of concrete based on ordinary Portland cement (OPC) and calcium sulfoaluminate (CSA) cement blends at low temperature …
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However, the performance of molasses on CSA cement is unknown though it is an effective plasticizer and retarder for OPC [39]. To this end, the main objectives of this study are as follows: (1) to evaluate the performance of molasses as plasticizer and retarder for CSA cement; (2) to examine the effect of molasses on the hydration reaction ...
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In this study, experiments were performed on the applicability of mortars and concretes based on calcium sulfoaluminate (CSA) binders to …
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In contrast, the CSA cement replacement for OPC was much lower as 10% in this study. On the other hand, the excessive amount of CSA cements in the blend may lead to uncontrollable rapid set of the binder, and thus the use of set-retarder is necessary for feasible use of CSA in OPC blends.
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Lee et al. [25] prepared 3D concrete materials by mixing 0.2% citric acid (retarder), 2% sodium sulfate (accelerator), and 17% calcium sulphoaluminate with ordinary Portland cement ...
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In this paper, use of chemical retardants, including citric acid, tartaric acid, and borax with CSA cement used alone and in combination with each other, and their effects on phase …
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In this study, experiments were performed on the applicability of mortars and concretes based on calcium sulfoaluminate (CSA) binders to facilitate the early strength development of ordinary …
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However, when using rapid-hardening cement or minerals as alternatives to OPC-based mixtures, it is necessary to consider the use of retarders and accelerators to effectively regulate and enhance the setting time and strength of the paste, in order to extend the operable time of material construction and achieve the required strength within the emergency repair …
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Although OPC (Ordinary Portland Cement) is the most commonly used concrete binder, it consumes 10-11 EJ of energy annually, and during its manufacturing process emits high amounts of carbon dioxide (Juenger et al., ... cement with no retarder was used as a control sample. All cement pastes and mortars were prepared at a w/c by mass of 0.40 ...
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Generally the initial setting time of cement (OPC) is 30 min. ... • The retarder was used as an admixture in concrete at hot weather condition to extend the initial setting time of concrete. • This thesis was carried out by using the gypsum and …
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They found that the wear resistance of MPC concrete was better than that of OPC concrete under the same strength. Hence, MPC can be used as a road repair or tunnel spraying material. ... to be less than 2.09%. In addition, the volume stability of MPC is affected by many factors, including the M/P ratio, retarder content, water-cement ratio, and ...
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Calcium sulfoaluminate cement (CSA) blended with ordinary Portland cement (OPC) can be used for various application fields like rapid setting, rapid hardening or expansive cements.
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When mixed with Portland cement, PG is a good cement retarder, and a binder can be made by mixing PG with cement clinker [14,15]. Show abstract Phosphogypsum (PG) is a solid waste product that is generated in the phosphoric acid manufacturing process, most of which is currently sent to landfills rather than reused.
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In a different study, Abalaka [11] reported that the initial and final setting time increased with increase in the quantity of sugar.A continuous decrease in the initial and final setting time was recorded at a sugar content of 0.08% and more. Zhang et al. [12] investigated the effect of aliphatic sugar alcohols and sucrose on the setting time of ordinary Portland cement …
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Hypothesis 1: CSA will require reduced curing periods compared to OPC. • Extended curing in RH is not required for CSA cement mixes beyond 3 days. o Samples cured for 2- 3 days reached similar compressive strengths, slightly lower amount of hydration products and slight increases in drying shrinkage.
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• In depth understanding of cement and SCMs hydration mechanisms and in depth understanding of interactions mechanisms of cement x admixtures (molecular level) • Ability to design …
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Compressive strengths of OPC paste (0% retarder, w/c = 0.4) and CSA2 cement paste cubes with dosages of retarder varying from 0 to 3%, w/c = 0.4. The effect of citric acid …
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Thus for M-40 Grade of concrete with OPC per cu.m of concrete on the basis of saturated and surface dry aggregates. Water = 150 kg/m 3 OPC = 375 kg/m 3 Fine Aggregate (sand) ... Specific gravity of Retarder Superplasticizer = 1.15; Addition of …
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OPC cement (type I), modified cement (type III and type IV), and PCC cement to see how the compressive strength of concrete develops over time with testing periods of 3 days, 7 days, 14 days, and 28 days. The research method used is an experimental study aimed at obtaining a comparison of compressive strength of concrete using OPC and PCC cement.
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Request PDF | A plant investigation into the use of treated phosphogypsum as a set-retarder in OPC and an OPC/FLY ash blend | This investigation describes the successful substitution of ...
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For the OPC samples that were treated with a surface retarder, growth is mostly concentrated on the cement part of the surface, not the aggregate. This holds especially true for the samples with the regular limestone aggregate, …
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The above results show that sodium gluconate is not only a good retarder but also a good water reducer. Its retardation on the setting times is attributed mainly to delaying the hydration of C 3 S in the Portland cement. Perez [9] hypothesized that sodium gluconate would rather adsorb directly onto C 3 S dissolution sites than chelate with Ca 2+ or silica to block its …
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design, raw materials, climatic conditions and concrete requirements. Trial mixes must be performed to establish the exact dosage rate required. Compatibility Sika® Retarder-22 may be combined with all types of Portland cement (OPC and SRC), concretes containing pozzolanic materials such as GGBS, PFA, mi-cro-silica and the following Sika products:
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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. ... Sika® Retarder-22 may be combined with all types of Portland cement (OPC and SRC), concretes containing pozzolanic materials such as GGBS, PFA, micro-silica and the following Sika products:
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The primary advantage of CSA cements is that concrete made with CSA instead of portland cement often achieves compressive strengths of in excess of 5000 psi in 24 hours; with CSA's, it's possible to achieve 28 day strength in 24 hours. …
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Phosphonates are widely used components of retarder and dispersant formulations in concrete and mortar. In this study, 11 different phosphonate retarders were analyzed for their retarding performance in ordinary Portland …
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This study explores a novel application of VC as a retarder for calcium sulfoaluminate cement (CSA). CSA has gained significant research interest for its potential as a low-carbon alternative of ordinary Portland cement (OPC). However, CSA sets very fast, leaving very limited processing time. Experimental studies carried out in this study show ...
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