高强钢丝绳网片—聚合物砂浆加固RC板的抗爆性能研究

发布时间：2018-04-18 11:01

本文选题：钢丝绳网片 + 聚合物砂浆　；参考：《北京建筑大学》2017年硕士论文

【摘要】：近些年来身边发生的爆炸事件屡见不鲜,包括小区住宅内遇到的燃气管道爆炸及住宅附近发生的危险品仓库爆炸,也包括极端分子对人群密集的公共建筑进行的恐怖爆炸袭击,造成大量的人员伤亡。随着恐怖袭击爆炸事件和意外爆炸事件的不断增多,爆炸安全防护问题也显得越来越突出。钢筋混凝土(RC)板作为建筑结构中重要的受力构件,其抗爆炸冲击水平对整个建筑结构的爆炸安全具有关键作用。因此,为了提高重要建筑结构的抗爆设计水平,需要对RC板进行抗爆加固设计。当前,可以通过粘钢、包钢、粘贴FRP等加固设计方法来提高原有RC板的抗爆性能,但是由于上述加固方法中均涉及有机结构胶的使用,影响其在爆炸产生的高温环境中的应用。高强钢丝绳网片-聚合物砂浆加固技术是一种新型的加固技术,与传统的加固措施相比,有较好的耐火性、耐腐蚀性和耐久性,并且已经在建筑结构与桥梁抗震加固中得到广泛应用,但对于该项加固技术在抗爆防护领域的适用性没有相关研究。因此,探究在爆炸荷载作用下高强钢丝绳网片-聚合物砂浆加固钢筋混凝土板的抗爆性能具有重要意义。本文先通过数值模拟的方式探究了在爆炸荷载作用下高强钢丝绳网片-聚合物砂浆加固钢筋混凝土板的抗爆性能,在验证模拟结果有效性的基础上,运用有限元软件ANSYS/LS-DYNA建立了与试验相关的有限元模型,考虑的因素有炸药量的大小和单面加固及双面加固的影响,同时进一步分析了加固参数砂浆强度、砂浆厚度、钢丝绳间距对加固效果的影响,为爆炸试验做好前期准备。之后,对7块不同加固参数下钢筋混凝土板进行了爆炸试验,对比分析了加固板与未加固板的试验结果,试验考虑的加固因素有砂浆强度、钢丝绳间距、钢丝绳预应力和销钉,并从构件的破坏形态、裂缝发展、钢筋的应力应变、位移时程曲线等方面进行了比较。论文主要研究结论如下:(1)应用有限元软件LS-DYNA数值模拟了钢筋混凝土板在爆炸荷载作用下的动态性能,首先验证了所建有限元模型及所选用材料性质的合理性和有效性,然后对各项参数进行了详细地分析比较,模拟结果表明:双面加固的加固效果和抗爆性能要优于单面加固;而且还发现砂浆加固层厚度和砂浆强度对钢筋混凝土板的加固效果影响比较显著。(2)根据试验现象和数据可以看出,高强钢丝绳网片-聚合物砂浆加固钢筋混凝土板的抗爆效果非常显著,板的破坏程度明显减轻。在比例距离分别为0.94 m/kg1/3、0.84m/kg1/3、0.70 m/kg1/3的爆炸荷载作用下,板发生了整体弯曲破坏,加固板的峰值位移和残余位移均大幅减小,受力主筋的应变也明显降低,并没有发生加固层整体剥离脱落破坏。(3)通过对比分析试验结果发现,加固层中的钢丝绳间距(短边×长边)为30mm×50mm的网片要比钢丝绳间距(短边×长边)为60mm×100mm的网片有更好的抗爆加固效果,使加固层的耗能能力显著提升,有效地减轻了板在爆炸荷载下的破坏程度。(4)通过试验结果还可以发现,对钢丝绳施加预应力能够有效降低板的最大位移和板底部受拉钢筋的最大应变;增加砂浆强度能够增强钢丝绳与砂浆之间的粘结能力,使加固层的整体变形能力和刚度增强,但并不是砂浆强度越高越好,会存在刚度不协调的问题;增加销钉能够有效防止爆炸荷载作用下加固层与原混凝土板发生剥离,但对于提高原构件的抗爆性能影响不大。(5)给出了高强钢丝绳网片-聚合物砂浆加固钢筋混凝土板的抗爆加固设计建议:1)根据构件的抗爆设计水平,合理选择钢丝绳间距提高加固层的耗能能力,以达到减小原钢筋混凝土板损伤程度的目的。2)建议在RC板的跨中位置设置一些抗剪销钉,用以增加加固层与原构件的界面承载力,同时应考虑销钉的增加对原混凝土构件的损伤。3)合理选择砂浆强度,使加固层和原钢筋混凝土构件的刚度合理匹配,以达到较好的抗爆加固效果。
[Abstract]:In recent years around the explosion events including dangerous goods warehouse It is often seen., and residential gas pipeline explosion occurred near the residential area encountered in the explosion, including terrorist bombings in crowded public buildings for extremists, resulting in a large number of casualties. With terrorist bombings and accidental explosion increasing problems safety explosion becomes more and more prominent. The reinforced concrete (RC) slab is an important component in the building structure, plays a key role in the anti explosion explosion safety level of the construction of the structure. Therefore, in order to improve the level of anti explosion design of the important buildings, the need for RC plate reinforcement design method. The current. By sticking steel, Baotou Steel, paste FRP reinforcement design method to improve the antiknock performance of the original RC board, but because of the reinforcement method were involved in The use of organic and structural adhesive, which affects its application in high temperature environment. The explosion of high strength steel wire mesh and polymer mortar is a new reinforcement technology, compared with the traditional reinforcement measures, has good fire resistance, corrosion resistance and durability, and has been widely applied in seismic strengthening building structure and bridge, but there is no research on the reinforcement technology in explosion protection field applicability. Therefore, exploring under the explosive load of high strength steel wire mesh and polymer antiknock performance of reinforced concrete slabs reinforced mortar has important significance. This article first through the numerical simulation of blast loading in high strength steel wire mesh and polymer mortar antiknock performance of reinforced concrete slabs, verify the validity of the results in the simulation based on the finite element software ANSYS/LS-DYNA build The finite element model and related test, effect of explosive and the size of single and double reinforcement reinforcement factors, and further analysis of the strength parameters of mortar mortar thickness, wire rope spacing on the reinforcement effect, do the preliminary preparation for the test. After the explosion, the 7 blocks of reinforced concrete plate parameters for the explosion test, comparison and analysis of the test results and the unreinforced plate reinforcement, reinforcement factor test takes into consideration the strength of mortar, steel wire rope spacing, wire rope and prestressed pin and cracks from the failure pattern, component development, stress and strain of steel, displacement and other aspects of the comparison. The main conclusions are as follows: (1) using finite element software LS-DYNA to simulate the dynamic performance of the reinforced concrete slab under explosion load, we proved that the finite element model and the The material properties of rationality and validity, then the parameters were discussed in detail, the simulation results show that the double reinforcement reinforcement effect and the antiknock performance is better than the single reinforcement; and also found that the mortar reinforcement effect of layer thickness and mortar strength of a reinforced concrete slab is obvious. (2) according to the experimental phenomena and the data can be seen, high-strength steel wire mesh and polymer mortar anti explosion effect of reinforced concrete plate is very significant, the extent of damage in the explosion load was reduced. In the distance ratio were 0.94 m/kg1/3,0.84m/kg1/ 3,0.70 m/kg1/3, the whole plate bending failure, strengthening peak displacement and residual displacement of the plate were greatly reduced, strain reinforcement was also decreased, and no reinforcement layer of whole peel off failure. (3) through the comparison and analysis of test results, and Solid layer of wire rope spacing (short side long edge * 30MM * 50mm) as compared to the wire rope spacing (short side long edge * 60MM * 100mm) network has better reinforcement effect, the reinforcement layer energy dissipation capacity significantly improved, effectively reduce the plate under blast load the extent of damage. (4) can also be found from the test results of prestressed steel wire rope can effectively reduce the maximum displacement and the maximum strain at the bottom of the plate plate tensile reinforcement; to increase the strength of mortar can enhance the bonding ability between rope and mortar, the overall deformation ability of reinforcement layer and stiffness enhancement, but not the strength of mortar is good, there will be no stiffness coordination problem; increase the pin can effectively prevent the blast loading reinforcement layer and the original concrete plate debonding, but has little effect to improve the antiknock performance of the original component. (5) presented high strength steel wire Design suggestions of mesh reinforced concrete slabs strengthened with polymer mortar reinforcement: 1) according to the level of anti explosion design components, reasonable selection of wire rope reinforcement layer spacing increased energy dissipation capacity, so as to reduce the damage degree of the original reinforced concrete slab to.2) suggest some shear pins are arranged on the RC board of the cross position with in order to increase the reinforcement layer and the original component interface capacity, should also consider the damage of the original pin.3 concrete) reasonable choice of mortar strength, the reinforcement layer and the original reinforced concrete member stiffness matching, to achieve better reinforcement effect.

【学位授予单位】：北京建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU375.2;TU352.13

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