长江下游疏浚特细砂碱矿渣混凝土动态力学特性试验研究

Experimental study on dynamic mechanical properties of dredged super fine sand and alkali slag concrete in the lower reaches of the Yangtze River

使用长江下游疏浚砂替代混凝土中的细骨料制备长江下游疏浚特细砂碱矿渣混凝土,通过直径为φ75 mm的分离式霍普金森杆开展动态冲击压缩性能试验,研究了5种不同疏浚砂掺量的混凝土动态力学性能,结果表明:长江下游疏浚砂碱矿渣混凝土属于应变率敏感型材料,随着应变率增加,峰值应力增大;动态强度相比静态强度有明显提高,50 s^(-1)为材料的应变率敏感值,且CEB规范中的DIF模型与材料拟合良好,可以使用其对材料动态峰值应力进行分析预测;同一应变率下,动态压缩强度随着疏浚砂掺量增加先上升后降低,仅从5组试验数据来看50%是最佳掺量。

Using dredged sand in the lower reaches of the Yangtze River to replace fine aggregate in concrete,the ultra-fine sand-alkali slag concrete in the lower reaches of the Yangtze River is prepared,the results show that the alkali-activated slag concrete in the lower reaches of the Yangtze River belongs to the strain rate sensitive material,and the peak stress increases with the increase of strain rate.The dynamic strength is obviously higher than the static strength,and 50 s^(-1) is the strain rate sensitive value of the material,and the DIF model in CEB specification can be used to analyze and predict the dynamic peak stress of the material,the dynamic compressive strength first increases and then decreases with the increase of the content of dredged sand.Only 50%is the best content according to the 5 groups of experimental data.