花岗岩骨料碱活性检验及抑制试验研究

Alkali Activity Test and Suppression Test of Granite Aggregate

对某工程用花岗岩骨料开展了碱活性检验及抑制试验研究。试验结果表明:两个料场的花岗岩骨料均评定为非活性骨料,掺入一定量的粉煤灰可有效抑制混凝土的碱-硅酸反应,且随着粉煤灰掺量的增加抑制效果得到增强;但鉴于采用混凝土棱柱体法检验花岗岩骨料碱活性时,其试件2a龄期膨胀率大于0.04%,且膨胀趋势还在发展,建议对重要部位混凝土采取一定措施来抑制碱-骨料反应,以保障混凝土的耐久性。

In this paper,alkali activity test and inhibition test of granite aggregates for a project are carried out.The test results show that the granite aggregates in both material yards are evaluated as inactive aggregates.The alkali-silica reaction of concrete can be effectively inhibited by adding a certain amount of fly ash,and the inhibiting effect will be enhanced with the increase of fly ash content.However,when the alkali activity of granite aggregates is tested by concrete prism method,the two-year age expansion rate of granite aggregates is more than 0.04%,and the expansion trend is still developing.It is suggested that certain measures be taken to restrain alkaliaggregate reaction of concrete in important parts to ensure durability of concrete.