Introduction. Calcium chloride, a chemical compound with the formula CaCl 2, is a salt that is widely known for its myriad of applications across various industries. It is an ionic compound comprised of calcium ions (Ca 2+) and chloride ions (Cl – ). This material is noteworthy for its hygroscopic nature, which means it can absorb water from ...
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Experimental results showed that adding 1.5% PAC increased compressive strength by 77.0%, 53.8%, and 19.4% at 3, 7, and 28 days. Resistance to chloride migration, water permeation, capillary water ...
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This study investigates chloride binding in blended cement pastes exposed to 0.5 M NaCl solutions (with and without pH adjustment) using X-ray diffraction and energy-dispersive X-ray spectroscopy image analysis (edxia).The aim is to better understand the effects of the binder type, the water-to-binder ratio and the pH on the chemical binding in …
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The binding of chloride ions to the hydration products together with the microstructure of cementitious materials affect the activity of the chloride ions at the …
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The leaching of calcium in cement hydrates, particularly in harsh environments, significantly affects the durability of cement-based materials. …
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Flake calcium chloride may be added up to 2% by weight of slag cement concrete in cold weather. As regards ... Slag cement should not be used in the concrete projects of …
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The replacement of Portland cement (PC) by fly ash (FA) or slag will cause low early age strength development of concrete. However, the addition of chemical additives can eliminate the well-known ...
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In this paper, the chloride penetration of slag-based geopolymer concrete (SGPC-M) exposed in the spray/splash zone of marine environment for 4 years was compared with the ordinary Portland Cement concrete (OPC-M) exposed in the same environment for 6 years period. It would be ideal for comparing the concrete samples …
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The important point in chloride permeability is the chloride binding capacity of the cement. Through studies, it is known that C 3 A binds chloride. ... Among the hydrates of slag cement, the content of calcium hydroxide is small and alkalinity is low, so the …
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The AAS binder consists of two components: ground granulated blast furnace slag (slag) and alkaline activator. The slag was sourced from a company in Hubei Province and has a specific surface of 530 m 2 /kg and a specific gravity of 2810 kg/m 3.The oxide components of slag, as determined using a PANalytical Axios, is listed in Table 1.The …
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Chloride-induced corrosion is one of the main reasons for durability degradation of reinforced concrete structures. The transport of chloride ions in concrete is directly related to the corrosion ...
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Calcium hydroxide is typically added to concrete during the mixing stage, as it helps with setting and hardening. This type of calcium is also highly alkaline, making it useful in controlling the pH level of the concrete. Calcium carbonate, on the other hand, is a fine powder that can be added after the concrete has been mixed and poured.
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Adding cementing agents such as lime, cement and industrial byproducts like fly ash and slag, with soil results in improved geotechnical properties. However, during the past few decades, a number of cases have been reported where sulfate-rich soils stabilized by cement or lime underwent a significant amount of heave leading to …
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Concrete systems exposed to deicers are damaged in physical and chemical ways. In mitigating the damage from CaCl 2 deicers, the usage of ground slag …
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Steel–concrete interface. The importance of the steel–concrete interface for C crit was already mentioned in a publication by Bäumel as early as in 1959 [2]. The author presented a schematic sketch of the interfacial zone and pointed out the protecting character of calcium hydroxide directly surrounding the steel.
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The rapid chloride conductivity test [39], [40], [41] was used to test the efficacy of resistance of the concretes to chloride ion penetration. This test measures the ionic flux across a concrete disc specimen (68 ± 2 mm diameter and 25 ± 2 mm thickness) due to a 10 V potential difference (see Fig. 1).The 10 V potential difference was obtained …
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In Portland cement system, large amount of research has verified the importance of alumina enriched supplementary cementitious materials (SCMs) in improving the chloride binding capacity, because the additionally provided aluminate in SCMs can react with calcium hydroxide to form Friedel's salt, therefore more free chlorides can be …
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Flake calcium chloride may be added up to 2% by weight of slag cement concrete in cold weather. As regards ... Slag cement should not be used in the concrete projects of which the impermeability is very important. 6 Good Heat Durability. Slag cement has good heat durability that can be used to prepare heat-resistant concrete because it contains ...
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Abstract. An improved hydration model of slag-blended cements, taking into account new insights, is used to estimate and quantify the hydration products of slag-blended cements. Individual chloride binding isotherms are used to correlate these amounts of hydration products with the amount of bound chlorides. A number of …
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With respect to heat evolution, calcium chloride has been observed to advance the peak corresponding to the maximum heat liberation from 8 h to 3 h as calcium chloride dosage increased from 0% to 2% [17].Chen et al. [27] reported that calcium chloride enhances both the main hydration peak and the exothermic shoulder of …
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The proposed model considers the porosity of concrete, chloride binding and electrochemical coupling between multi-species. • The influence mechanism of relevant factors on both chloride penetration and reinforcement corrosion onset is discussed. • Slag content is proved to be the most important influencing factor on chloride transport in ...
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It is obvious that, the calcium leaching process of cement-based materials is the fastest in the mixed solution, followed by ammonium chloride solution, and the minimum in sodium chloride solution. The leaching process characterized by the tested average porosity is consistent with that from the tested leaching depth.
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T05:01:34+00:00 Calcium Chloride in Portland Cement Concrete If dry calcium chloride is used, it should be added free of lumps to the aggregates in the mixer drum during mixing, or to the mixed concrete just before discharge Concentrated calcium chloride should not come into direct contact with dry cement as it may cause flash set …
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Slag cement is a hydraulic binder that, like portland cement, reacts with water to form cementitious material (calcium-silicate hydrate or CSH). It also, similar to a pozzolan, …
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The use of slag cement usually improves workability and decreases water demand. ... several authors have investigated the effect of sodium nitrate and calcium nitrate in admixed concrete, which is an effective corrosion inhibitor [162,163,186 ... Chloride contaminated cement mortar(3% of NaCl (wt%)) Sodiumpyro phosphate: 0%-- …
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The tri-calcium aluminate (C3A) phase of the ordinary portland cement (OPC) plays a dominant role in binding the chloride ions, but little quantitative information is …
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The concrete with 6% calcium stearate had a higher chloride concentration than the concrete with 4% calcium stearate, because high dose of calcium stearate introduced more air bubbles and caused a less dense microstructure of the concrete. The addition of 4% calcium stearate was appropriate for improving the chloride resistance …
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The authors declare that there are no conflicts of interests regarding the publication of the article titled "Hydration mechanism of calcium chloride modified coal gasification slag-based backfill materials". Acknowledgments. This research was supported by the National Natural Science Foundation of China (Nos. 52222404, 52074212, …
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slag-blended cement are in between hydrated PC and calcium silicate hydrate (C-S-H) with Ca/Si of 1.0. A two-layer surface complexation model was used to predict chloride …
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1. ABSTRACT Four concrete mixtures with water/cement ratios 0.5 and 0.6 have been investigated. The permeability of chloride ions was measured using the potentiometric titration. Total and soluble ...
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