商洛市丹江河砂碱活性研究

A Study of Alkali Reactivity of Sands from Danjiang River in Shangluo

骨料的碱活性影响混凝土结构的安全与耐久,对商洛市商州区段丹江及其主要支流进行全线分析,在具有代表性的河砂地点实地取样,采用人工四分法制备砂样,进行岩相鉴定,并将砂样制成胶砂试件使其处于在一定碱环境下,以不同龄期、温度、压力、湿度环境中的胶砂膨胀率为判据,测定丹江河砂试样胶砂膨胀率,并进行试验分析。结果表明,所检测的商州区段丹江河砂为非碱-硅酸反应活性骨料,商洛市商州区段丹江河砂在砂源稳定前提下不具有碱活性,但具有潜在的碱活性,需要建立长期动态的碱活性监测系统,以保证商洛市混凝土结构的安全性和耐久性。

Alkali activity of aggregate affects the safety and durability of conerete structure, analysis is done on Danjiang River in Shangzhou, Shangluo, and its main tributary with samples from representative location of the sands field, using artificial four legal sands preparation, lithofacies identification and sands made of mortar test part makes the under alkali environment, to different age, temperature, pressure and humidity environment in the mortar expansion ratio as a criterion and determination of Danjiang River sands specimen mortar expansion ratio, test and analysis. The results show that the of Danjiang River sands for non alkali silica reactivity of aggregate, Danjiang River sands of Shangzhou is stable under the premise does not have active alkali, but has the potential alkali reactivity, need to build the long-term dynamics of alkali activity monitoring system to ensure the safety and durability of the concrete structure in Shangluo.