矿粉掺量对胶粉轻骨料混凝土力学性能的影响

Effect of Mineral Powder Content on Mechanical Properties of Rubber Powder Lightweight Aggregate Concrete

以掺入3%(质量分数) 20目的胶粉轻骨料混凝土为研究对象,研究矿粉掺量分别为0%、5%、10%、15%、20%、25%、30%胶粉轻骨料混凝土的力学性能。通过环境扫描电镜(ESEM)、核磁共振检测(NMR)及气泡间距仪来测定其孔隙特征、微观形貌,同时结合宏观力学实验,探讨矿粉掺量对其力学性能的影响。试验结果表明:矿粉掺量为15%时胶粉轻骨料混凝土的力学性能最佳;矿粉的掺入可以改善胶粉轻骨料混凝土的孔隙结构,当掺量为15%时孔隙度、渗透率较基准组分别降低了51. 9%、99. 3%,100μm以上的气泡弦长频率降低至16. 5%,当掺量大于15%时,孔隙度、渗透率逐渐增加,100μm以上的气泡弦长频率增加至30. 6%。

3%(mass fraction)of 20 mesh rubber powder lightweight aggregate concrete was taken as the research object,study on the mechanical properties of rubber powder lightweight aggregate concrete with 0%,5%,10%,15%,20%,25%and 30%mineral powder content.Determination of pore characteristics and micromorphology by environmental scanning electron microscopy(ESEM),nuclear magnetic resonance(NMR)and bubble spacing,at the same time,combined with macroscopic mechanical experiments,the influence of mineral powder content on its mechanical properties was discussed.The results show that the best mechanical properties of rubber powder lightweight aggregate concrete when the content of mineral powder is 15%;the incorporation of mineral powder can improve the pore structure of rubber-based lightweight aggregate concrete.When the dosage is 15%,the porosity and permeability are reduced by 51.9%and 99.3%,respectively,and the chord length of the bubble above 100μm is reduced to 16.5%.When the dosage is more than 15%,the porosity and permeability are gradually reduced,the frequency of the chord length of the bubble above 100 jjim is increased to 30.6%.