氧化镁膨胀剂对粉煤灰混凝土力学与耐久性能的影响研究

Study on the Effect of Magnesium Oxide Expansion Agent on Mechanics and Durability of Fly Ash Concrete

制备了粉煤灰掺量为10%、氧化镁掺量为0~10%的C40粉煤灰混凝土试件,利用室内试验方法测试了不同氧化镁掺量试件的坍落度、扩展度、抗压强度、劈裂抗拉强度、碳化深度和抗氯离子侵蚀性能,研究了氧化镁掺量对粉煤灰混凝土力学与耐久性能的影响规律。研究结果表明:粉煤灰混凝土的坍落度和扩展度随着氧化镁掺量的逐渐增大而逐渐减小;粉煤灰混凝土的抗压强度、抗拉强度、抗碳化性能和抗氯离子侵蚀性能随氧化镁掺量的增大而增大;综合分析各项性能和性价比,粉煤灰混凝土中氧化镁的最佳掺量为4%~6%。

The C40 fly ash concrete specimens were prepared with the 10% fly ash content and 0 ~ 10% magnesium oxide content.Slump,extension ratio,compressive strength,splitting tensile strength,carbonation depth and chloride ion erosion resistance of fly ash concrete were tested under the different dosage of magnesium oxide by indoor test method.The influence law of magnesium oxide content on the mechanical and durable properties of fly ash concrete was studied.The results showed that,the slump and expansion of fly ash concrete decreased with the increase of magnesium oxide content;the compressive strength,tensile strength,carbonization resistance and chloride ion corrosion resistance of fly ash concrete increased with the increase of magnesium oxide content;though comprehensive analysis of the performance and cost performance,the best content of magnesium oxide in fly ash concrete was determined as 4%~6%.