硫酸铵腐蚀混凝土性能劣化时变规律及预测

通过在5%浓度硫酸铵溶液中长期浸泡,对不同水灰比、不同浆骨比、不同粉煤灰掺量的混凝土试件进行腐蚀试验研究,得到0~120 d腐蚀龄期下试件抗压强度的劣化规律。采用灰色关联分析方法研究了不同因素对混凝土抗压强度影响的显著程度,通过构建GM(1,1)预测模型对受硫酸铵腐蚀的混凝土强度劣化规律及服役寿命进行预测。结果表明:水灰比0.4、浆骨比0.28和粉煤灰掺量10%的受腐蚀混凝土抗腐蚀性能较强,随水灰比、浆骨比和粉煤灰掺量比例增大,抗压强度降幅明显。构建的GM(1,1)预测模型具有较高的精度,运用该模型在预测受腐蚀混凝土的寿命中,粉煤灰掺量10%、水灰比0.4及浆骨比0.28的受腐蚀混凝土分别比其它影响因素相同下的受腐蚀混凝土增加247%,125%,74%。

Regularity of Compressive Strength Deterioration and Grey Prediction of Concrete Corrosion in Ammonium Sulfate Solution

Corrosion tests were carried out by immersing concretes in ammonium sulfate solution of 5% concentration. The concretes are of different material compositions of water cement ratio, paste aggregate ratio and content of fly ash. The regularity of deterioration of compressive strength of immersed concretes during 0-120 d corrosion age were obtained. The grey correlation analysis method was used to research the influence of different factors on the compressive strength of concrete, and the GM (1,1) prediction model was established to forecast the service life and strength deterioration of the concretes in ammonium sulfate solution. Results show that the concretes with water cement ratio of 0.4, paste aggregate ratio of 0.28 and fly ash content of 10% have better anti-erosion performance. Moreover, the compressive strength of concretes declines significantly with the increases in water cement ratio, paste aggregate ratio and fly ash dosage. The prediction results by the GM(1,1) model indicate that the lifetimes of concretes with water cement ratio of 0.4, paste aggregate ratio of 0.28 and fly ash content of 10% increase by 247%, 125% and 74% than those of concretes with the same influence factors, respectively.