共查询到20条相似文献,搜索用时 78 毫秒
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全轻页岩陶粒混凝土和钢筋之间的粘接作用较为复杂,粘接强度受钢筋类型、锚固长度、混凝土强度等因素影响,通常采用中心拉拔试验方法分析全轻页岩陶粒混凝土的粘接效果。对此,采用该方法进行了12组不同标准的全轻页岩陶粒钢筋混凝土试件粘接强度测试试验,分析了试件拉拔破坏和劈裂破坏二种破坏形态,对比了不同钢筋直径、钢筋类型和混凝土强度等级下试件的粘接强度变化,并提出了更加合理的极限粘接强度计算方式。以期促进全轻页岩陶粒混凝土的深入研究和在建筑行业的广泛应用。 相似文献
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研究铜电极与碳纤维/环氧复合材料的粘接工艺,比较铜的表面处理方法对于粘接强度和导电性的影响,并验证粘接的可靠性.首先分别用机械打磨、化学表面处理、表面电镀方法对铜片进行处理,然后通过铜粉导电胶与碳纤维/环氧复合材料粘接,测试粘接强度及电阻率,再通过湿热老化实验,对粘接的可靠性进行比较.测试结果表明,经化学表面处理的铜片与碳纤维/环氧复合材料粘接强度达到1.34 MPa,老化后强度保留率为76%;电阻率为4.19 Ω*m,老化后电阻率增加率为4.8%.从而确定化学表面处理方法得到的粘接强度和导电效果较佳. 相似文献
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进行铝合金表面处理工艺、胶粘剂粘接与硫化工艺对粘接强度影响的研究,结果表明采用化学氧化处理方法,可以使铝合金与硅橡胶的粘接强度稳定在3.0MPa以上。 相似文献
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F—4的粘接强度与温度、压力、时间、接头形状和受力情况等因素有关。本试验是通过弹簧压力圈对粘接面施加压力的方法提高粘接强度,并取得了令人满意的结果。 相似文献
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目前可用于水下粘接的EP(环氧树脂)胶粘剂用水下固化剂种类不多,主要是一些憎水类改性胺固化剂(如810和301P等)。以不同种类的水下固化剂作为试验对象,着重探讨了水下固化剂的本体黏度、相应水下EP胶粘剂的某些性能(如水下凝胶时间、水下拉伸剪切强度及水下压缩强度等)。研究结果表明:水下EP胶粘剂的适宜凝胶时间为1h左右;水膜隔离胶粘剂/被粘物的界面问题只影响拉伸剪切强度,而不影响压缩剪切强度,故水下固化剂的憎水性良好时,相应EP胶粘剂的压缩强度相对较高,但其钢/钢拉伸剪切强度会受到一定的影响;810和301P具有一定的憎水性,并且相应EP胶粘剂的水下凝胶时间均为1h左右,故不同黏度的810和301P复配可制得综合性能更好的水下EP胶粘剂。 相似文献
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采用环氧树脂-DDS固化体系作为胶接剂,探讨了各种金属表面处理方法、胶接时对胶接面施加的压力、胶层厚度等因素对胶接剪切强度的影响.结果表明,对不锈钢工件采用盐酸氧化法及草酸-硫酸氧化法进行表面处理,得到的胶接剪切强度最好;对铝合金工件采用硅酸磷酸钠法进行表面处理,得到的胶接剪切强度最高.胶接时对胶接面施加0.1~0.4Mpa的压力、胶层厚度在0.10~0.23 mm范围内时胶接效果最好.由于处理液对金属表面产生适度的化学腐蚀,改变了金属表面的物理化学性质,表现出更好的可浸润性和更强的表面吸附力,可以有效地提高胶接剪切强度. 相似文献
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介绍了一种含新型基质树脂的粘结性偶联剂的双糊剂型正畸粘合剂,其与牙釉质的剪切强度为21.2MPa。它与粉液型粘合剂相比,具有操作简便,结固时间可调,性能稳定之优点。经正畸临床426个托槽的粘结及1年左右的临床初步观察,该粘合剂性能优良,粘结效果良好。 相似文献
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Adhesive bond strength and durability were investigated for steel substrates which had been cathodically electroprimed before bonding. Lap shear and torsional impact strengths of two model epoxy adhesives were evaluated. Very poor strengths and durability were found for one adhesive, which was cured with a mixture of three amine curing agents. Scanning electron microscopy and analysis of primer susceptibility to interaction with the curing agents suggested that, for the high concentrations of curing agent in the amine-cured adhesive, chemical and physical degradation of the primer occurred during cure at elevated temperature.
For the second adhesive, which was cured with a single imidazole catalyst, excellent strength and durability were obtained, with no evidence of primer degradation. Surprisingly, for this adhesive, strengths to primed steel were up to 88% higher than to cleaned (i.e., degreased) bare steel. The concurrent improvements in environmental durability over bare steel, as assessed by water immersion and salt spray accelerated exposures, were attributed to the more favourable surface energetics of the adhesive/primer interface. 相似文献
For the second adhesive, which was cured with a single imidazole catalyst, excellent strength and durability were obtained, with no evidence of primer degradation. Surprisingly, for this adhesive, strengths to primed steel were up to 88% higher than to cleaned (i.e., degreased) bare steel. The concurrent improvements in environmental durability over bare steel, as assessed by water immersion and salt spray accelerated exposures, were attributed to the more favourable surface energetics of the adhesive/primer interface. 相似文献
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以正硅酸乙酯(TEOS)为无机前驱体,γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)为偶联剂,HCl为催化剂,采用溶胶-凝胶(Sol-Gel)法制得了硅溶胶,并以此硅溶胶对自制的紫外光固化环氧丙烯酸酯(EA)胶黏剂进行改性。通过傅立叶红外光谱(FT-IR)表征了EA的结构,通过热分析以及力学性能测试表征了此复合胶黏剂的热性能以及力学性能。结果表明:硅溶胶的加入显著地提高了环氧丙烯酸酯胶黏剂的耐高低温性能以及热稳定性,当硅溶胶的固体质量为体系总质量的40%时,复合胶黏剂在-196℃、室温、100℃的拉伸剪切强度分别提高了600%、320%、400%;热分解温度提高了50℃。 相似文献
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聚氨酯胶粘剂在NaCl水溶液中的耐久性机理研究 总被引:1,自引:0,他引:1
采用拉伸实验方法测试了聚氨酯胶粘剂胶接试样在盐溶液中浸泡前后的拉伸剪切强度,并考察了水、NaCl水溶液的温度、NaCl的含量以及应力对胶粘剂粘接强度的影响。利用红外谱图分析了浸泡前后胶粘剂化学结构的变化。实验结果表明:聚氨酯胶粘剂的粘接强度在NaCl水溶液中的下降速率比在蒸馏水中的下降速率慢。温度的作用主要表现为在浸泡初期能加速聚氨酯胶粘剂的降解和粘接强度下降,但是在浸泡中后期,则其作用变小。聚氨酯胶粘剂粘接强度的下降趋势在浸泡初期随NaCl含量的增加而减缓,在浸泡中后期,其结果刚好相反。胶粘剂的粘接强度随载荷的增加而急剧下降。 相似文献
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Shraddha Jagatap Abbas Razavykia Belingardi Giovanni 《Journal of Adhesion Science and Technology》2019,33(7):715-735
This study investigates the effect of five independently-controlled process variables and variable combinations on the shear strength of autoclave-bonded film adhesive joints. Studied variables include the cure temperature, cure pressure and their respective ramp rates, as well as the duration of cure time. A full factorial design of experiment (DoE) at two levels for each variable is conducted with 3 replicas of each test. Test coupons are made of two layers of polycarbonate lexan that are autoclave-bonded using aliphatic polyether film adhesive (Huntsman PE399). Two set of test joints are used for generating test data on shear strength and failure mode. Bonded joints in the first set are tested prior to any environmental cycling, in order to generate baseline data on joint shear strength and failure mode. However, samples from the second set of autoclave-bonded joints were heat-cycled, in an environmental chamber at high relative humidity, prior to testing for shear strength. Test data on shear strength and failure mode is statistically analyzed using ANOVA. 相似文献