共查询到19条相似文献,搜索用时 125 毫秒
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基于市场上现有的商业化原材料,通过改变硬质聚氨酯泡沫配方中多元醇的类型,寻找最佳阻燃性能的配方.选取常规高羟值聚酯多元醇A、常规低羟值聚酯多元醇B、含氮聚酯多元醇C、含溴和氯阻燃聚醚多元醇D、含溴阻燃聚醚多元醇E作为硬质聚氨酯泡沫配方中的多元醇组分,通过测定泡沫氧指数等阻燃性能,来研究多元醇对硬质聚氨酯泡沫阻燃性能的影响.结果 表明:由于含氮聚酯多元醇C结构中含有三(2-羟乙基)异氰脲酸酯基团,同时具有氮和异氰脲酸酯的阻燃特性,因此其制得的硬质聚氨酯泡沫氧指数达到27.5%,阻燃性能最佳,同时具有环保、低毒的优点. 相似文献
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《新型建筑材料》2017,(8)
研究了稀释剂、固化剂、消泡剂、硅微粉及硅烷偶联剂用量对制备的改性环氧基混凝土裂缝注浆料粘度、抗压强度、抗弯性能、粘结剪切强度及正拉粘结强度的影响。结果表明,当m(环氧树脂E-44)∶m(固化剂593)∶m(稀释剂501)∶m(稀释剂692)∶m(KH-550)∶m(消泡剂B-313)∶m(硅微粉)=100∶31∶10∶15∶1.5∶0.5∶30时,制备的环氧注浆料的综合性能最优。其粘度为1450 m Pa·s,适用期为65 min,7 d抗压强度为64 MPa,7 d抗弯强度为35 MPa,呈非碎裂破坏;7 d钢对钢粘结剪切强度为14 MPa,7 d钢对混凝土正拉粘结强度为3.6 MPa,呈混凝土内聚破坏,符合GB/T 50728—2011《工程结构加固材料安全性鉴定技术规范》对改性环氧基混凝土裂缝注浆料的性能要求。 相似文献
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同步注浆是盾构施工的必备及关键工序,同步注浆材料性能的好坏直接影响隧道周围地层位移和地表沉降。选用水泥、河砂、粉煤灰、膨润土、缓凝剂和抗水分散剂等作为原材料,探讨了水泥、缓凝剂和抗水分散剂等原材料对浆液凝结时间、流动度、抗压强度和抗水分散性能等指标的影响规律及同步注浆浆液配合比的优化方向。试验结果表明:水泥是影响凝结时间和抗压强度的主要因素,掺入复合缓凝剂的注浆材料凝结时间可调,且浆液流动度经时损失小;掺入抗水分散剂的注浆材料具备优良的抗水分散性能,从而可以保证了地层中浆液的完整性,充分填充盾尾间间隙。 相似文献
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新型抗水分散和抗水溶蚀双液注浆材料的设计与应用 总被引:1,自引:0,他引:1
结合水泥-水玻璃双液注浆材料快速胶凝、抗水分散性能好和碱激发硅铝质胶凝材料耐久性好的特点,提出了抗水分散和抗水溶蚀双液注浆材料的理想结构模型和设计方法。选择含C3S、C2S和高活性硅铝质成分的物质作原料,加入定量的水混合均匀成A液,然后与水玻璃(B液)混合制备一种具有优异抗水分散和抗水溶蚀性能的新型工业废渣双液注浆材料,并在武汉长江隧道注浆工程中得到了实际应用,获得了良好的效果。 相似文献
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一种新型环氧灌浆材料的制备及性能研究 总被引:3,自引:0,他引:3
利用Pluronic多元醇聚醚L35与双酚A型环氧树脂反应,然后按一定比例加入活性稀释剂,制得环氧灌浆材料A组分;由2-甲氧基-4-甲基苯酚、三甲基六甲撑二胺与多聚甲醛反应制得酚醛胺类固化剂为B组分.该环氧灌浆材料的抗压强度在2d时可达到16 MPa,7d时可达到67 MPa,其固结体28 d的各项力学性能均达到JC/T 1041-2007标准的要求. 相似文献
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选用m(铝酸盐水泥)∶m(普通硅酸盐水泥)∶m(水石膏)=85%∶4%∶11%的三元胶凝体系,通过控制凝结时间制备出了自流平水下抗分散铝酸盐水泥基砂浆。通过测试其水陆强度、pH值、浊度并结合SEM微观分析,探究了铝酸盐水泥基砂浆抗分散性。结果表明,通过酒石酸和葡萄糖酸钠双掺解决了铝酸盐水泥基砂浆流动度损失大的问题。再生乳胶掺量增加优化了砂浆的抗分散能力。通过模拟水下现场浇筑,发现水下成型的铝酸盐水泥基砂浆试件的28 d抗压强度均在70 MPa以上,形成了控制凝结时间的水下成型制备技术。SEM揭示控制凝结时间的浇筑技术,水下成型的铝酸盐水泥砂浆试件内部密实、孔隙率低。 相似文献
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交河故城土体裂隙灌浆材料性能试验 总被引:2,自引:0,他引:2
以PS为主剂,粉煤灰和交河故城原生土为填充材料,氟硅酸钠为固化剂制得PS-(F+C)浆液,测定浆液的初凝速度,并观测结石体的收缩变形性。测试结石体在不同龄期时的强度,对比固化温度、固化剂掺量、PS模数、PS浓度以及水灰比等因素对结石体强度的影响。对PS-(F+C)浆液结石体进行水稳定性、抗冻融性、安定性和耐碱性等耐候性试验。试验结果表明,PS-(F+C)浆液和易性与可灌性非常好,它与交河故城生土遗址相兼容,浆液的凝结速度适中且可调,水灰比为0.60时的线性收缩率约2.6%,PS主剂浓度是决定浆材长期强度的最关键参数,吐鲁番夏天较高的固化温度有利于气硬性PS-(F+C)浆液结石体强度的增长,而且浆液结石体的耐候性能良好。PS-(F+C)浆液将用于封护加固交河故城生土遗址中的裂隙,防止雨水沿裂隙冲蚀下切崖体。 相似文献
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通过乙醇封端的二异氰酸酯,对乙烯基酯树脂进行改性,在其侧链上接枝上强极性的氨酯键,合成了一种黏度低于100mPa.s,可灌性好的新型水下灌浆材料。在本实验室的灌浆工艺下,该浆材可用于水下混凝土结构补强并堵水,测得的水下粘接强度在3.0MPa以上,抗压强度在100MPa以上。本文就这种水下灌浆材料的制备,及其中引发剂、催化剂和双亲组分单体的用量等对材料的水下粘接性能影响进行了逐个单因素分析,找到了最优用量。结果表明,在最优用量时,改性乙烯基酯树脂浆材,作为水下修补材料,具有优良的粘接补强性能。 相似文献
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混凝土灌注桩桩体注浆是指当桩基桩身质量或桩端持力层存在缺陷,达不到设计要求时,需要进行的补强加固处理。如何保证加固的效果,需要进行实验研究,以便为工程应用提供参考,本文对混凝土灌注桩桩体注浆加固进行了实验研究,结果表明,灌浆料无论早期强度还是后期强度都远高于C35混凝土抗压强度,其中骨料的含水率对灌浆料的试块抗压强度影响并不明显,而含泥沙量的大小对灌浆料试块无论从早期抗压强度还是后期强度都有显著的影响。 相似文献
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Physical and mechanical properties of chemically grouted sand 总被引:1,自引:0,他引:1
C.A. Anagnostopoulos T. Papaliangas S. Manolopoulou T. Dimopoulos 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2011,26(6):718-724
It is generally accepted that only chemical grouts or solutions are available to penetrate and fill narrow joints or soils with very small pore size. Over the last 30 years a few hundreds of different compounds have been used for this purpose showing a wide spectrum of properties. Epoxy resins are among the compounds that are commonly used in building restoration because of their high strength and durability against mechanical or physical erosion. The purpose of this paper is to investigate the improvement of the physical properties (water permeability, porosity and dry unit weight) and mechanical properties (compressive strength, elastic modulus, splitting tensile strength and strength under triaxial stress conditions) of fine sand mixed with a water-soluble two component epoxy resin is, since there is not any published data about the efficiency of such high strength material in ground improvement. The experiments were carried out using different solutions of epoxy resin, which had epoxy resin/water (ER/W) ratio of 2.0, 1.5, 1.0 and 0.5. Cylindrical specimens were prepared by mixing fine sand with an adequate quantity of epoxy resin and were used for compression, splitting tensile and triaxial strength tests. Development of compressive and splitting tensile strength was evaluated from tests at the ages of 3, 7 and 28 days whereas strength under triaxial conditions was determined on specimens cured for 28 days.The results of this study indicate that the epoxy resin solutions, especially the solutions with low water content resulted in higher strength, lower porosity and lower water permeability of the sand, improving significantly the physical and mechanical properties of the fine sand. 相似文献
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《Construction and Building Materials》2007,21(3):546-555
This study aims to investigate the effect of different concentrations of fly ash on the mechanical properties and durability of polymer concrete compounds prepared with low concentrations of resins. Two different binders were used: orthophtalic and isophtalic polyester. The properties of the resulting materials were studied through compressive strength, flexural strength and chemical attack by acetic acid (CH3COOH), citric acid (C6H8O7), formic acid (CH2O2), lactic acid (C3H6O3), sulfuric acid (H2SO4), a cola soft drink and distilled water (H2O). Sample microstructure after chemical attack was studied using SEM. Results show that both isophtalic and orthophtalic polyester polymer concrete display good mechanical and chemical behavior. It was seen that orthophtalic polyester polymer concrete, when prepared with sand and fly ash, behaves similarly to isophtalic polyester polymer concrete, despite the properties of the isophtalic resin being superior to the orthophtalic variety. 相似文献