碱激发剂对不同掺量粉煤灰UHPC的影响

在UHPC材料中,通过在粉煤灰0%、20%、30%、40%的掺量下掺入不同碱激发剂(氢氧化钙、氢氧化钠、硫酸钠、硫酸钙、碳酸钠、水玻璃)测试砂浆浆体流动性、经时损失和胶砂试件抗压强度、抗折强度。结果表明:在UHPC材料中,随着粉煤灰掺量的增加,流动性改善明显,对抗压抗折强度影响较大;在粉煤灰掺量较小时,碱激发剂效果不明显,随着粉煤灰掺量的增加,碱激发剂的效果逐渐凸显出来;在粉煤灰掺量为30%、40%时,硫酸钙为最为突出的碱激发剂。

Effect of alkali activator on UHPC with different fly ash contents

In UHPC materials, the fluidity, time-consuming loss, compressive strength and flexural strength of mortar specimens were tested by adding different alkali activators (calcium hydroxide, sodium hydroxide, sodium sulfate, calcium sulfate, sodium carbonate, sodium silicate) at the content of 0%, 20%, 30% and 40% fly ash. The results show that in UHPC materials, with the increase of fly ash content, the fluidity improves obviously, which has a great influence on the compressive and flexural strength; when the fly ash content is small, the effect of alkali activator is not obvious; with the increase of fly ash content, the effect of alkali activator is gradually prominent; when the fly ash content is 30% or 40%, calcium sulfate is the most prominent alkali activator.