不同硫酸钠溶液浓度对混凝土力学性能及内部结构孔隙影响研究

Study of Mechanical Properties and Internal Structural Porosity of Concrete under Different Sodium Sulphate Concentrations

为了研究不同浓度硫酸钠对混凝土力学性能及内部孔隙结构的影响,对在标准养护及在10%、15%、20%、25%四种不同浓度硫酸钠溶液浸泡7个月混凝土试件进行单轴压缩试验,并且通过核磁共振试验分析试件浸泡前后内部结构孔隙分布情况进行研究。结果表明,随着硫酸钠浓度的升高,混凝土全应力-应变曲线表现出一定的右移倾向,混凝土峰值应力、弹性模量逐渐下降,而峰值应变逐渐增大;硫酸钠浓度的增加促使混凝土孔隙数目增多,导致混凝土力学性能劣化程度提高。

In order to study the influence of different concentrations of sodium sulfate on the mechanical properties and internal pore structure of concrete,uniaxial compression tests were carried out on concrete specimens after standard curing and soaking in four different concentrations of Na_(2)SO_(4) solution of 10%,15%,20%,25%for 7 months,and the pore distribution of the internal structure of the specimens before and after immersion was analyzed by NMR test.The results show that with the increase of sodium sulfate concentration,the total stress-strain curve of concrete shows a certain right shift tendency,the peak stress and elastic modulus of concrete gradually decrease,while the peak strain increases gradually,the increase of sodium sulfate concentration makes the number of concrete pores increase,leading to the improvement of concrete mechanical properties deterioration.