• Chloride Attack on Concrete Structures Cause and Prevention

    Causes of Chloride Attack on Concrete StructuresPrevention of Chloride Attack on Concrete StructuresChloride Content Limit in Concrete StructuresThe attack of chloride on concrete structures can be happened either from inside of the concrete or through the ingress of chloride from outside to the inside of concrete structures. The chlorides exist in concrete during the casting process due to the following reasons: 1. Use of seawater for the concrete mixing process 2. Use of calcium chloride as an additive to increase the setting time 3. Use of aggregates that contained chlorides w在theconstructor上查看更多信息发布日期: May 10, 2013
  • Hexavalent Chromium in Cement Manufacturing: Literature

    Jul 24, 2015· As outlined in reference BCA (2006), the directive: 1) prohibits the placing on the market or use of cement or cement preparations which contain, when hydrated, more than 2 ppm (0.0002%) of soluble Cr (VI); 2) requires that where cement or cement preparations have a soluble Cr (VI) content of 2 ppm or less, when hydrated, due to the presence of

  • Hexavalent Chromium in Portland Cement ASTM International

    Studies at a California cement plant showed that more than half of the hexavalent chromium in the cement was contributed by the grinding media in the finish mill. Attempts to reduce the chromium to its benign trivalent form with ferrous sulfate failed in full-scale trial grinds, due to oxidation of the ferrous iron.

  • Hexavalent Chromium in Cement Manufacturing: Literature Review

    Chromium in the cement can originate from: 1) raw materials or fuel, 2) magnesia-chrome kiln refractory brick, if used, 3) wear metal from raw mill grinding process, if chromium alloys are used, and 4) additions such as gypsum, pozzolans, ground granulated blast furnace slag, mineral components, and cement

  • EFFECT OF RAW MATERIALS AND REDUCTION AGENTS ON

    Chromium in the cement can originate from: 1) raw materials or fuel, 2) magnesia-chrome kiln refractory brick, if used, 3) wear metal from raw mill grinding process, if chromium alloys are used

  • The Effect on the Performance of Cement Grinding Aid

    Mar 26, 2017· certain effect of improving cement fineness and specific surface area,has a positive effect for the preparation of the composite cement grinding aid. 3.1.2 Effect of monocomponent grinding aid on compressive strength Effect of monocomponent grinding aid on compressive strength, As shown in figure 2: 32

  • Impact of ALKALY, SULPHURE and CHLORINE in Kiln operation

    As a result, C2S content is increased and C3S content is decreased in the clinker, causing a reduction in cement strengths. 4. If chloride is very high, it will first combine with all of the alkalis present forming alkali chlorides which will recirculate in the kiln and increase the probability of buildups in the preheater.

  • Health Effects of Hexavalent Chromium California

    Health Effects of Hexavalent Chromium A fact sheet by CalEPA’s Off of Environmental Health Hazard Assessment November 9, 2016 . What is hexavalent chromium Hexavalent chromium, also known as chromium 6 (Cr6), is the toxic form of the metal chromium. While some less toxic forms of chromium occur naturally in the environment

  • Hexavalent Chromium Factsheet

    Hexavalent chromium exposure occurs through . breathing it in, ingesting it in or water, or direct contact with the skin. What are the known health effects of inhaling hexavalent chromium Hexavalent chromium compounds have been shown . to cause lung cancer in humans when inhaled. The Report on Carcinogens. lists hexavalent chromium

  • Hexavalent Chromium Overview Occupational Safety and

    Hexavalent chromium [Cr(VI)] is one of the valence states (+6) of the element chromium. It is usually produced by an industrial process. Cr(VI) is known to cause cancer. In addition, it targets the respiratory system, kidneys, liver, skin and eyes. Chromium metal is added to alloy steel to increase

  • Hexavalent Chromium in Portland Cement ASTM International

    Studies at a California cement plant showed that more than half of the hexavalent chromium in the cement was contributed by the grinding media in the finish mill. Attempts to reduce the chromium to its benign trivalent form with ferrous sulfate failed in full-scale trial grinds, due to oxidation of the ferrous iron.

  • The Influence of C3A Content in Cement on the Chloride

    The present study concerns the influence of C 3 A in cement on chloride transport in reinforced concrete. Three modified cement was manufactured in the variation of the C 3 A content, ranging from 6.0 and 10.5 up to 16.9%. The setting time of fresh concrete was measured immediately after mixing, together with the temperature at the time of initial set.

  • Hexavalent Chromium in Cement Manufacturing: Literature Review

    Chromium in the cement can originate from: 1) raw materials or fuel, 2) magnesia-chrome kiln refractory brick, if used, 3) wear metal from raw mill grinding process, if chromium alloys are used, and 4) additions such as gypsum, pozzolans, ground granulated blast furnace slag, mineral components, and cement

  • Hexavalent Chromium in Cement Manufacturing: Literature

    With regard to chromium and health and safety aspects, the water-soluble compounds of chromium in cement are most relevant, specifically compounds of the form Cr (VI). Chromium in the cement can originate from: 1) raw materials or fuel, 2) magnesia-chrome kiln refractory brick, if used, 3) wear metal from raw mill grinding process, if chromium alloys are used, and 4) additions such as gypsum

  • Preparation of ultrafine fly ash by wet grinding and its

    Jul 15, 2020· 2.4.7. Immobilized chloride ratio (ICR) The capacity of cement-based materials to immobilize chloride ion was evaluated with leaching method, according to Test Code for Hydraulic Concrete (SL 352-2006, Chinese standard). 10.00 g hydrated cement powder (<0.15 mm) was immersed in 100 mL deionized water.

  • Effect of the Type of Surface Treatment and Cement on the

    The effect of a new passivation treatment, obtained by immersion of the galvanized reinforcements in a trivalent chromium salts based solution, on the chlorides induced corrosion has been investigated. To investigate also the effect of cement alkalinity on corrosion behaviour of reinforcements, concretes manufactured with three different European cements were compared.

  • The Effect on the Performance of Cement Grinding Aid

    Mar 26, 2017· certain effect of improving cement fineness and specific surface area,has a positive effect for the preparation of the composite cement grinding aid. 3.1.2 Effect of monocomponent grinding aid on compressive strength Effect of monocomponent grinding aid on compressive strength, As shown in figure 2: 32

  • Impact of ALKALY, SULPHURE and CHLORINE in Kiln operation

    As a result, C2S content is increased and C3S content is decreased in the clinker, causing a reduction in cement strengths. 4. If chloride is very high, it will first combine with all of the alkalis present forming alkali chlorides which will recirculate in the kiln and increase the probability of buildups in the preheater.

  • (PDF) A review on the existence of chrome in cement and

    Chromium in the cement can originate from: 1) raw materials or fuel, 2) magnesia-chrome kiln refractory brick, if used, 3) wear metal from raw mill grinding process, if chromium alloys are used

  • Health Effects of Hexavalent Chromium California

    Health Effects of Hexavalent Chromium A fact sheet by CalEPA’s Off of Environmental Health Hazard Assessment November 9, 2016 . What is hexavalent chromium Hexavalent chromium, also known as chromium 6 (Cr6), is the toxic form of the metal chromium. While some less toxic forms of chromium occur naturally in the environment