《Journal of Materials in Civil Engineering》杂志刊登“混凝土坝中预测磁黄铁矿氧化的一种新的未反应核模型”

作  者：Izelman Oliveira,Sergio H. P. Cavalaro, Antonio Aguado

刊  物：《Journal of Materials in Civil Engineering》，25卷第3期(2013年3月)，372-381页

关键词：未反应核模型，磁黄铁矿，硫酸盐侵蚀，混凝土坝，膨胀

摘  要：黄铁矿和磁黄铁矿是自然界的硫化铁中最丰富的的矿物质，用来生产混凝土的骨料中可能存在这两种矿物质。在水和氧气存在的条件下，这种化合物会产生膨胀反应，可能会对混凝土造成严重的结构破坏。考虑到混凝土坝中所用的大体积材料以及周围环境对坝体变形的限制，这种反应显得尤为重要。在这种情况下，适当的修补计划的确定取决于对膨胀反应演变的预测和坝体结构变形预测。虽然描述固体颗粒与气体反应的模型可达到预测的目的，但是没有专门模拟大坝中这种反应的模型。本文介绍了一种新的动力学模型，这个模型基于磁黄铁矿氧化的未反应核模型。这种新的模型所得到的结果与直接应用未反应核模型得到的结果相比，有很大差异。通过广泛的参数研究，提出了一个简化的本构方程来估计混凝土坝中磁黄铁矿氧化的动力学行为。用这个本构方程所做的估计与不同粒径的试验中所获得的试验数据一致。

New Unreacted-Core Model to Predict Pyrrhotite Oxidation in Concrete Dams

Authors: Izelman Oliveira,Sergio H. P. Cavalaro, Antonio Aguado

Journal: Journal of Materials in Civil Engineering, Volume 25, Issue 3 (March 2013) ,372-381

Keywords: Unreacted-core model;Pyrrhotite;Sulfate attack;Concrete dam;Expansion

Abstract: Pyrites and pyrrhotites are the most abundant minerals of the iron sulfide group in nature and may be found in the aggregates used to produce concrete. In the presence of water and oxygen, such compounds generate expansive reactions that may have severe structural damages. This is especially critical in concrete dams, given the large volume of material used and the restrictions in movement imposed by the surroundings. In these cases, the definition of adequate rehabilitation programs depends on the prediction of the expansive reaction evolution and the future behavior of the structure. Although models that describe solid particle–gas reactions may be used with this purpose, none were specifically developed to simulate this phenomenon in dams. This paper introduces a new kinetic model based on the unreacted-core model for pyrrhotite oxidation. The comparison of the results obtained with this new model and with the direct application of the unreacted-core model show significant differences. Following an extensive parametric study, a simplified constitutive equation is proposed to estimate the pyrrhotite oxidation kinetics in concrete dams. The estimations performed with this constitutive equation agree with the experimental data obtained in the tests of different particle sizes.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29MT.1943-5533.0000531