乌鲁木齐地区凝灰岩骨料碱活性及抑制措施试验研究

乌鲁木齐地区建筑工程面临因使用凝灰岩骨料而发生碱骨料反应的问题。以砂浆棒快速法为基础,对乌鲁木齐地区凝灰岩骨料碱活性进行判定;进一步分析了单掺矿渣微粉、复掺粉煤灰和矿渣微粉对凝灰岩骨料碱活性的抑制效果,并与单掺粉煤灰进行比较。试验结果表明:乌鲁木齐地区凝灰岩骨料具有碱活性;随着单掺矿渣微粉、复掺粉煤灰与矿渣微粉掺量的增加,砂浆试件膨胀率降低;单掺矿渣微粉掺量达到45%,复掺粉煤灰与矿渣微粉掺量达到30%时,即可有效抑制凝灰岩骨料碱活性;在3种抑制措施中,单掺粉煤灰抑制凝灰岩骨料碱活性效果最好,复掺粉煤灰与矿渣微粉次之,单掺矿渣微粉抑制凝灰岩骨料碱活性效果较差。

Experiments on the Alkali-activity and Inhibition Measures for Tuff Aggregate in the Area of Urumqi

Due to the use of tuff aggregate ,Architectural Engineering could occur the Alkali Aggregate Reaction problem in Urumqi area .Based on the accelerated mortar bar method we determined the alkali activity of tuff aggregate in Urumqi and analyzed the inhibitory effect of the alkali activity of tuff aggregate ,when single slag or the admixture of fly ash and slag were used .Also ,the single fly ash were compared .Experimental results show that the tuff aggregate had alkali ac-tivity in the area of Urumqi ,with the increase of the content of single slag or the admixture of fly ash and slag ,the ex-pansion rate of mortar was reduced .The alkali activity of tuff aggregate could be effectively inhibited ,when the content of single slag reached 45% or fly ash and slag reached 30% .The single fly ash had the best inhibitory effect of the alkali activity of tuff aggregate in the three of measures and the admixture of fly ash and slag followed ,at last single slag was worse .