Huang Weibo, Zhang Rui, Wang Xu, Lyu Ping, Ju Jiahui, Gao Fuyin, Yan Shuai
School of Civil Engineering, Qingdao University of Technology, Qingdao 266520, China.
Qingdao Shamu Advanced Material Co., Ltd., Qingdao 266000, China.
Polymers (Basel). 2022 Aug 24;14(17):3458. doi: 10.3390/polym14173458.
In order to further study the blast mitigation performance of polyurea and to investigate the protection mechanism and damage characteristics of polyurea-protected structures under contact explosion loads, based on earlier work, this paper investigated the response and energy absorption performance of polyurea under various frequency loads. Qtech T26 blast mitigation polyurea (T26 polyurea) was adopted to protect the reinforced concrete (RC) slab and damage analysis of the post-explosion specimens was carried out at micro and macro levels. The response and energy absorption capacity of the material towards different frequency loads were investigated by dynamic mechanical analysis (DMA). Protective performance of T26 polyurea on RC slab was examined with a 10 kg TNT contact explosion test. Scanning electron microscopy (SEM) was employed to analyze the microscopic fracture morphology of the typical areas of the coating after the explosion. The chemical structure changes of the blast-face coating before and after the explosion were compared by Fourier transform infrared spectroscopy (FTIR). The results show that the glass transition region of T26 polyurea is -40 °C to 10 °C, which is a large temperature range, and the microphase separation of T26 polyurea is low. It is significantly influenced by the ambient temperature and loading frequency. The energy absorption of T26 polyurea is realized through the interaction between the hard and soft segments. When the frequency is between 10 Hz and 10 Hz, the loss factor of T26 polyurea is between 0.20 and 0.31, which exhibits a good energy dissipation performance. In the contact explosion of 10 kg TNT, the fragmentation rate of the coated specimen decreased significantly compared with that of the unprotected specimen, realizing the zero fragmentation protection effect on the back-blast face. The maximum deformation area and the main energy absorption area of T26 polyurea under contact explosion is the ring area outside the longitudinal deformation area. The chemical structure of T26 polyurea changed significantly after the explosion; typically the N-H bonds, etc., were broken and the percentage of hydrogen bonding was reduced. T26 polyurea has realized the protection effect of zero fragmentation of large-equivalent contact explosion, which has a high application value for blast mitigation and blast-fragmentation prevention in actual engineering.
为了进一步研究聚脲的抗爆性能，探究聚脲防护结构在接触爆炸载荷作用下的防护机理及损伤特性，本文在前期工作的基础上，研究了聚脲在不同频率载荷作用下的响应及能量吸收性能。采用Qtech T26抗爆聚脲（T26聚脲）对钢筋混凝土（RC）板进行防护，并对爆炸后试件进行微观和宏观层面的损伤分析。通过动态力学分析（DMA）研究了该材料对不同频率载荷的响应及能量吸收能力。采用10 kg TNT接触爆炸试验考察T26聚脲对RC板的防护性能。利用扫描电子显微镜（SEM）分析爆炸后涂层典型区域的微观断裂形貌。通过傅里叶变换红外光谱（FTIR）比较爆炸前后爆轰面涂层的化学结构变化。结果表明，T26聚脲的玻璃化转变区域为-40℃至10℃，温度范围较大，且T26聚脲的微相分离程度较低。其受环境温度和加载频率影响显著。T26聚脲的能量吸收是通过硬段和软段之间的相互作用实现的。当频率在10 Hz至10 Hz之间时，T26聚脲的损耗因子在0.20至0.31之间，表现出良好的能量耗散性能。在10 kg TNT接触爆炸中，涂覆试件的破碎率与未防护试件相比显著降低，实现了对背爆面的零破碎防护效果。T26聚脲在接触爆炸下的最大变形区域和主要能量吸收区域为纵向变形区域外侧的环形区域。爆炸后T26聚脲的化学结构发生了显著变化；典型的N-H键等发生断裂，氢键百分比降低。T26聚脲实现了大当量接触爆炸零破碎的防护效果，在实际工程中的抗爆和防碎片方面具有较高的应用价值。
