【摘 要】
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Numerous industrial by-products have potential for use as alternative supplementary cementitious materials (ASCMs) in concrete.The objective of the present study is to define the reactivity and the im
【机 构】
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Université Paris-Est, Ifsttar, 14-20 Bd Newton, 77447 Marne-la-Vallée cedex 2, France
【出 处】
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The 14th International Congress on the Chemistry of Cement (
论文部分内容阅读
Numerous industrial by-products have potential for use as alternative supplementary cementitious materials (ASCMs) in concrete.The objective of the present study is to define the reactivity and the impact on reinforcement corrosion of three ASCMs: glass powder, biomass fly ashes, and calcined sewage sludge.The first results, based on chemical tests and thermodynamic analysis have highlighted the behavior of these ASCMs and led to the design of concretes which exhibit good mechanical properties with a replacement of Portland cement of 15 or 20%.It can be highlighted that the main parameter considering the mechanical properties is the water to binder ratio;here 0.40 and 0.55 ratios are studied.The second part of the study deals with chloride and carbon dioxide transfer properties of the concretes.Due to its pozzolanic reactivity, glass powder significantly increases carbonation process but limits chloride penetration in concrete.Regarding biomass fly ashes and calcined sewage sludge, both showing low pozzolanic reactivity, the properties of concretes as regard to chloride penetration and carbonation decrease slightly although the mechanical properties are close to those of the reference concrete made with only Ordinary Portland Cement.These results confirm that mechanical properties are not an appropriate indicator to evaluate the transfer properties of concretes.The third part of the study focuses on the electrochemical properties of steel in reinforced mortars prepared with ASCMs.The results of these last tests show that the steel passivation is not affected by the presence of ASCMs.A new accelerated test which would allow to follow both the chloride transfer properties of concrete, carbonated or not, and the initiation of steel corrosion is proposed for the future studies.
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