钢筋混凝土板震塌碎片特性试验

Test of the Fragments Characteristics of Reinforced Concrete Slab Caused by Spalling

为研究钢筋混凝土板震塌碎片速度、质量和毁伤特性,对三种厚度靶板开展了14炮次爆炸试验,通过图像捕捉法获取了碎片初始速度,依据量纲分析,建立了速度与震塌系数的定量关系。对试验结果统计分析发现,有限厚度板(≤300 mm)无论发生何种破坏类型(震塌、贯穿、冲切),产生的单个碎片质量均以60 g以下为主,其中30 g以下碎片主要为单粒石子,30~60 g碎片以砂石胶结体为主,且震塌系数越小,单粒碎片尺度越小、质量越小。对等效模拟物的毁伤状态分析表明,混凝土类单粒碎片无法对25 mm厚松木板形成有效贯穿,松木板的损伤主要表现为冲击伤,板表面呈现较多冲击压痕。由于碎片自身强度有限,部分碎片对目标撞击过程中易出现碎裂或者粉碎,从而导致无法继续侵入。虽然单粒碎片无法侵入松木板,但其数量较多、单位面积上密度较大,易对人员造成大面积表皮伤。碎片束(碎片云)对目标物的持续冲击时间可达200~500 ms,可使目标产生损伤累积,最终导致目标物严重损毁或者人员伤亡。

In order to study the velocity,mass and damage characteristics of reinforced concrete slab,fourteen blast tests were carried out on three thickness targets.The initial velocity of fragments was obtained by image capture,based on the dimensional analysis,the quantitative relationship with the collapse coefficient was established.Statistical analysis of test results show that no matter what failure mode occurs to the target with limited thickness(≤300 mm),the mass of single fragment produced is mainly less than 60 g,of which the fragment below 30 g is mainly single stone,and the fragment between 30 g and 60 g is mainly sand-stone cement.The sma-ller the collapse coefficient is,the smaller the scale and the mass of the single fragment is.The damage state analysis of the equivalent simulant show that the single concrete fragment can’t penetrate the 25 mm thick plank effectively.The damage of wood board is mainly impact damage and marks on the board surface.Due to the limited strength of the fragments themselves,some fragments are likely splintering or smash in the process of impact on the target,which makes it impossible to continue to penetration.Although a single piece of fragment can’t penetrate into the board,it has a large number and a large density per unit area,which is easy to cause a large area of skin injury to personnel.The sustained impact times of fragment’s ejection on the target can be as long as 200~500 ms,which can cause damage accumulation the target and eventually lead to serious damage of the target or casualties.