一种新型轻质泡沫混凝土挤入行为的试验研究

Experimental Study of Squeeze Behavior for a Kind of New Lightweight Foamed Concrete

轻质泡沫混凝土是一种很重要的拦阻飞机/车辆等运动的新型阻滞材料。为了研究其挤入特性,利用CSS4410电子万能试验机和Dynatup9250落锤试验机,针对不同相对密度的轻质泡沫混凝土,在挤入速度从2×10-5 m/s到7.8m/s范围内的力学特征、破坏形式、减速度特性和抗压强度模型进行了系统研究。结果表明:此材料抗挤入阻力随挤入速度和材料相对密度增加而显著增加;挤入过程为材料脆性压溃/压实界面在弹性区的运动过程;挤入前端材料压溃/压实体积随挤入深度增加而增大且头部更尖锐;抗挤入过载加速度值与材料相对密度呈二次幂关系。故为保障人员及飞机等安全,应尽可能采用低相对密度材料。

Lightweight foamed concrete is a kind of new and important runway arresting material for airplanes and other vehicles. To understand its squeeze property, CSS4410 electric universal testing machine and Dynatup9250 drop-hammer testing machine were used. At different squeeze speed ranging from 2×10 5m/s to 7.8m/s, its squeeze mechanic characteristics, failure mode, deceleration property and anti-squeeze strength model were systematically studied respectively for lightweight foamed concrete with different relative densities. Results show that the anti-squeeze resistance of this material increases with squeeze speed and material relative density increase; material squeeze is a process of brittle material crushing/ solidification boundary moving in elastic region; crushing/ solidification volume during squeeze increases with squeeze depth increasing and its head shape becomes more sharp; anti-squeeze deceleration of this material has second power relationship with material relative density. So in order to ensure the safety of crew members, passenger and airplane, lower relative density lightweight foamed concrete should be adopted as far as possible.