纤维粉煤灰改良膨胀土无侧限抗压强度试验

摘要

The effectiveness of basalt fiber-fly ash as an additive in reinforcing expansive soils was evaluated.A serious of unconfined compressive strength test was carried out to study the influence of alkali-activator,fiber content,fly ash content and curing time on the bearing capacity of expansive soil.The results showed that for the three kind of alkali activator(Na2CO3,Na2SiO3 and NaOH),Na2SiO3 had a better alkali activation effect;adding fiber and fly ash could both improve the bearing capacity of expansive soil.Moreover,the improving effect was better when added together.The addition of fibers greatly improved the fracture toughness of soil and the strength of reinforced soil grows with curing age.%为研究碱激发粉煤灰、玄武岩纤维对膨胀土的改良效果,开展无侧限抗压强度试验,分析了碱激发剂的类型及掺量、纤维和粉煤灰掺量以及养护龄期对改良土强度的影响.研究结果表明:Na2 CO3、Na2 SiO3、NaOH 3种碱激发剂中,Na2 SiO3的激发效果较好;单掺纤维或粉煤灰均能够提高土体的强度,纤维粉煤灰共同改良的膨胀土强度高于相同掺量下的单掺纤维和单掺粉煤灰改良土强度;纤维的加入改善了粉煤灰土样的脆性破坏模式;随着养护龄期的增长,改良土的强度逐渐提高.