第8卷第1O期2008年5月 科学技术与T程 @Vo1.8 No.10 May 2008 1671—1819(2008)10—2602—06 Science Technology and Engineering 2008 Sci.Teeh.Engng. 桥面铺装黏结材料的制备与性能研究 杨 朋 张肖宁 吴少鹏 (华南理工大学道路7-_程研究所,广州510640;武汉理丁大学硅酸盐材料工程教育部重点实验室 ,武汉430070) 摘要 制备并研究了新型桥面黏结材料。选用柔性和耐久性能优越的单组分聚氧酯作为黏结材料,探讨了其与集料的黏 结机制。利用优质集料和国际稀浆封层协会微表处技术指南(ISSA A143)中Ⅱ型级配制备出了新型桥面黏结材料。性能研 究表明其具有良好的抗拉伸剪切性能、抗疲劳性能和抗水损害性能。该材料是一种性能优良的桥面铺装材料。 关键词 聚氨酯 中图法分类号固化机理 催化利 疲劳性能 A TU528.044; 文献标志码Generally,asphalt and other waterproof materials are applied in adhesion and waterproofing layer broad— ly,which are easily affected by aging and environmen— tal issues_1.2]However,these materials show tempera— .as new type of bonding material for bridge deck overlay was prepared through selected curing mechanism in this study.Meanwhile,related properties were investi— gated with direct tensile and shear test,fatigue test and moisture sensitivity test. ture dependency,whose anti—shear performance drops unceasingly in high temperature.Therefore,adhesion 1 Experimental 1.1 RaW materials and waterproofing layer failed because of material deg— radation.A new type composite material should be de— veloped with excellent temperature stability and anti— shear performance,which shows signiicantf improve— One component moisture—curable polyurethane is selected with its properties tested according to GB/ T19250—2003,seen in Table 1. Table 1 Physical properties of polyurethane ment to performance and lifetime of bridge deck over— lay. Polyurethane is an excellent material widely used in waterproofing.Polyurethane binder contains isocya— nate group(一NCO一)and carbamic acid methyl group (一NH—CO0一),which exhibits high polarity and reac— tivity .In particular,polyurethane binder can cure at normal temperature,which provides plenty of advanta— ges to construction.Polyurethane once applied in bind— ing course,could absorb stress of bridge deck overlay and prolong the lifespan because of its good flexibility and durability.Polyurethane based composite material Two groups of Basalt ifne aggregates(4.75~ 2.36 mm group,A group and less than 2.36 mm group,B group)were selected for aggregates of polyu— 2008年1月14日收到 rethane—aggregates mixture with fineness modulus of 2. 维普资讯 http://www.cqvip.com 10期 杨朋,等:桥面铺装粘结材料的制备与性能研究 2603 09.sand equivalent value of 83.5%according to JTG E42-2005.River sand was selected for fine aggregates of polyurethane—aggregates mixture,and limestone filler with hydrophile coefifcient at 0.8.Triethylamine(ana— lytical reagent)and dibutyltion dilaurate(DBTDL, chemically pure)made in Shanghai Reagent First Fac— tory are selected as catalyzers. SBS modified asphalt was selected as a compari— son,which is produced by Koch Asphalt Co.Ltd of Ezhou,Hubei Province,China with penetration of 8.9 mm at 25℃.ductility of62 cm at 15℃,and softening point 69℃. With design method of Slurry Seal(People’s Re— public of China’s Industyr Regulation,2000),polyu— rethane—aggregates mixture was designed according to ISSA A143 11 type gradation.Table 2 presents the gra— dation of polyurethane—aggregates mixture.A:B:river sand:filler=31.25:12.75:12.5:12.5.Asphalt mixture was prepared as a comparation,whose asphalt was added with the same amounts of polyurethane and the same gradation. Table 2 Gradation of the Composite Material 1.2 Test methods 1.2.1 Mixing process Polyurethane—aggregates mixture was prepared ac— cording to the determined ratio.First,aggregates and ifller were dried and blended for 90 s.Polyurethane of required amount and catalyzers were then added and blended for another 90 s.After mixing,polyurethane— aggregates mixtures were filled into the molds,and then specimens were prepared for tests. 1.2.2 Best polyurethane content According to standard test methods of bitumen and bituminous mixtures for highway engineering and mix— ing process,best polyurethane content was deter— m Bed 1.2.3 Optimization of catalyzers Triethylamine and dibutyltion dilaurate are ap— plied as catalyzers to increase curing speed of the con— posite materia1.The amounts of catalyzers were opti— mized by curing time and the relationships of curing thickness and curing time. 1.2.4 Curing mechanism Mixed polyurethane—aggregates mixture was equa— blv laid 0n the surface of cement floor slabs(300 mm x 300 mm x 50 mm).Then standard blocks of the bond test instrument(ZQS6--2000A,Beijing Siswir Science&Technology Co..Ltd.)were laid on the sur— face of polyurethane—aggregates mixture。Bond strength was tested once every 30 rain.This study was tested at 0,10,20,40 and 60 ̄C respectively and relative hu— midity of60%一80%. 1.2.5 Direct shear and tensile test After mixing,polyurethane—aggregates mixture was put into the ready wheel urtting test mold(300 mm x 300 mm x 50 mm).After 10 h curing,specimens (‘p=100 mm)for direct shear test were obtained by drilling core machine.Sketch map for direct shear test was shown in Figure 1.Specimens(100 mm x30 mm x 30 mm)for direct tensile test were obtained by rock cutting machine.Sketch map for direct tensile test was shown in Figure 2. Figure 1 Direct shear test Figure 2 Direct tensile test 维普资讯 http://www.cqvip.com
科学技术与工程 8卷 1.2.6 Fatigue Property of the Composite Material Indirect tensile fatigue test ]was used to estimate the fatiuge property of polyurethane—aggregates mixture and the prepared asphalt specimens.Fatigue life of specimens was calculated according to equation =K( ) Where。Nf is fatigue life; T is required stress (N/cm );n is slope of logarithm curve between stress and fatigue life;and K is intercept of logarithm curve between stress and fatiuge life.Fatigue specimens were tested at the stress ratio of 0.2,0.4 and 0.6 respec— tively with load frequency 10 Hz,sine wave and at 15oC. 1.2.7 Moisture sensitivity test According to standard test methods of bitumen and bituminous mixtures for hi吕0 ∞ —8∞g ghway engineerrT ing,resist— ance to moisture property of polyurethane-aggregates mixture and the asphalt specimens wasinvestigated. 2 Resuits and discussions 2.1 Optimization of polyurethane content Fiugre 3 presents optimized selection of polyure— thane content.Generally,the optimum denseness va— ries from 2 mm to 3 mm according to JTlJ 052—_2005. As shown in Figure 3,denseness of the composite ma— terila increases with polyurethane content increasing from 1 8%to 22%of total mixture.Meanwhile.exper— imental results indicate that polyurethane—aggregates mixture becomes extremely thin when polyurethane content was above 22%,and it was too thick to mix when polyurethane content was below 1 8%.Consider- ing the construction workability of this composite mate— rial,the best polyurethane content was determined to be 20%. 2.2 Optimization of catalyzers Catalyzers were prepared according to four groups as shown in Table 3.As can be observed from Table 3.4 3.2 一 ◆ ◆ 3 ◆ 2.8 - ◆ ◆ ◆ 2.6 ◆ ◆ ◆ 2.4 - ◆ 2.2 2 ◆ 1.8 ◆ ◆ 1.6 一 ◆ ◆ l_4 l7 l8 l9 20 21 22 23 Polyurethane contenff ̄ Figure 3 Optimization of Best Polyurethane Content ——●一 Catalyzer① +Catalyzer② ——Ir__ Catalyzer③ —*一Camlyzcr④ 75 70 晷 sII。 吾 《墨IpI_10∞ ∞ ∞ 0 l00 2oo 3oo Solidifying time/min Fiugre 4 Relation of Curing Thickness and Curing Time 3,synergistic effects happen between triethylamine and DBTDL.For example,compared①and②,dosages of the two catalyzers decrease result in increasing ca- irng speed.Figure 4 shows that—NCO-shows synergis— tic effects in single component curing system with— NH2一,H2 O and urethane groups emerged in curing. CO2 is resultant of reaction of H2 O and—NCO— which seems mainly contributed to foaming.Triethyl- amine,as a kind of tertiary amines catalyzer,shows great influences on accelerate reaction of H2 O and —NCO一.Hereby,more CO2 are produced by the in- crease amounts of triethylamine.However,foam cau- ses air voids in mixture,which shows inlfuences on cu- irng thickness.Curing thickness increases with the in— crease of foam.High thickness shows unstable for deck 维普资讯 http://www.cqvip.com
1O期 杨朋,等:桥面铺装粘结材料的制备与性能研究 雪 昱∞ ulpu0∞ 0 0 0 0 0 0 0 0 0 2605 2 9 8 7 6 5 4 3 2 l 0 《尝《皂8皇舞兰∞芑5 4 3 2 overlay especially in heavy load.Therefore,when 2 2 The bonding strengths of different temperatures in— 2 2 1 using catalyzer①,curing thickness shows less change over time compared with other group.The composite material was close—grained and stable.Hereby,orga— notion compounds(DBTDL)could be used as the cat— alyzer for this material for bridge deck overlay. Table 3 Curing time results 0 100 200 300 Solidfying time/arin —◆_Solidifying at0℃. —-_Solidifying at10℃ —●・Solidilying at 20℃. —*一Solidi ng at 40℃ — Solidilying at60℃ Figure 5 Relation of bond s ̄ength and curing time 0 10 20 30 40 50 60 Temperature/℃ Figure 6 Direct shear strength 2.3 Curing mechanism of polyurethane-aggre- gates mixture Figure 5 indicates that polyurethane—aggregates mixture can cure at both low and high temperature. crease by curing time.As also shown in Figure 5, bonding strengths didn’t show signiifcant increase with temperature ascending.In other words,polyurethane— aggregates mixture could cure at a relatively low tem— perature such as room temperature but perform a simi— lar performance compared with ones curing at high tem— perature.Generally,bonding material should be con— structed at extremely high temperature about l5O℃. which causes serious waste of energy.Polyurethane—ag— gregates mixture shows an economy way to bridge con— struction. 2.4 Direct shear and tensile properties Figure 6 and Figure 7 illustrate the resuhs of di- rect shear strength and direct tensile strength test,re— spectively.As shown in Figure 6,the direct shear strength shows only 1 l%decrease when temperature 5 5 increased from 0 to 6O℃.Meanwhile.direct tensile strength decreases only 10%when the temperature in— creased from 0 to 6O℃.seen in Figure 7.The reason of these is that polyurethane adheres to aggregates firm— ly after curing,which shows no sensitivity to tempera— ture.And the physical properties are very stbale as the strong adhesions of polyurethane and aggregates.Here— by,polyurethane—aggregates mixture is insensible to temperature and could be used at both low and high temperature with excellent properties. Fiugre 7 Direct tensile strength 对¨ 维普资讯 http://www.cqvip.com
26O6 科学技术与工程 8卷 曼 邕 趸 :薯 Figure 8 Fatiuge properties of polyurethane mixture and asphalt mixture 2.5 Fatigue properties Figure 8 shows that the fatigue life of polyure— thane—aggregates mixture and SBS modiifed asphalt mixture.Polyurethane—aggregates mixture shows 13%—。18%life time higher than that of SBS modiifed asphalt mixture at the same stress ratio.As also pres— ents in Figure 8,polyurethane—aggregates mixture could perform long lifespan at longtime high stress ratio compared with SBS modified asphalt mixture.Polyure— thane—aggregates mixture shows strong durability and fatiuge resistance to high stress ratio,which seems per— form good once applied in bridge deck overlay. 2.6 Moisture sensitivity Polyurethane・-aggregates mixture would be dam・- aged by moisture,since water could penetrate into the deck overlay easily.When adhesion failure occurs,the bridge deck overlay will be separated from other struc— tural layers consequently.Therefore,resistance to moisture is very vital property for bonding materials. Results of moisture sensitivity are shbwn in Table 4.It can be concluded that this composite material shows better resistance to moisture than normal asphalt bond— ing materia1.Although the former’s water absorption is small,the latter still have higher split strength,freez— ing thaw strength and tensile strength ratio.Polyure— thane has good waterproofing property and could make aggregate separate from water,so this new type polyu— rethane based composite material for bridge deck over— lay could be used in moist condition Table 4 Results of moisture sensitivity NOTE:TSR=tensile strength ratio;=routine split strength(MPa); and=freezing thaw split strength(MPa). 3 Conclusions Here we may draw the following conclusions. (1)New type polyurethane based composite mate— rial(polyurethane—aggregates mixture)for bridge deck overlay is prepared by using one component moisture— curable polyurethane,aggregate,sand and filler. (2)According to ISSA A143 11 type gradation, Polyurethane・-aggregate mixture with the determined ra・- tio was prepared with selected curing mechanism.Ex— perimentla results of polyurethane—aggregates mixture shows excellent direct tensile and shear properties,fa— tigue resistance and moisture resistance. (3)Polyurethane—aggregates mixture is proved to be an excellent bonding material for bridge deck over— lay for its excellent performance. 1 Johnson,Bridge deck waterproofing membrane evaluation.Proceedings of the International Conference on Cold Regions Engineering,1998 2 Koichi M.Adhesion of bituminous waterproofing membranes for bridge applications,Swiss Federal Lab for Materials Testing and Re— search(EMPA),1999 3 KOGA.One component moisture—curable u ̄thane polymer composi— tions,adhesives for stones using and manufacture.JP 2000064860, 2000 4 AASHTO Provisional Stnadard.Stnadard test method for determining the fatigue life of compacted hot mix asphalt(HMA).AASHO Desig一 (下转第2615页) 维普资讯 http://www.cqvip.com
1O期 陈矛,等:基于nRF系列无线收发芯片的飞机线路识别系统设计 26l5 优点,实现了对飞机各机载系统线路的综合测试。 参考文献 2张立科.Visual c++串口通信工程开发实例导航.北京:人民邮 电出版社,2003 3沙占友.新编使用数字化测量技术.北京:国防工业出版社,1998 1赵茂泰.智能仪器原理及应用.北京:电子工业出版社,1999 Design for Plane Line Identification System Based on nRF Wireless Dispatch Chip CHEN Mao,LI Gang,XIE Ping,CHEN Peng (Fimt Aviation College of Air Force,Xinyang 464000,P,R.China) [Abstract]The design for Brainpower Identification system of airplane line is introduced.The design of hard— ware circuit and software flow are discussed.The key technologies are analyzed carefully.Many shortcomings have been solved.The system has many merits such as transportable,simplicity of operation and good reliability. [Key words] nRF line brainpower identify design (上接第2606页) nation:TP 3l—_94,American Association of State Highway and Transportation Ofifcils,USA,1996 a5 People’S Republic of China’S Industry Regulation:Standard Test Methods of Bitumen and Bituminous Mixtures for Highway Engineer- ing(JTJ052-2000).China Communications Press,2000 Preparation and Study of Bonding Material for Deck Overlay YANG Peng,ZHANG Xiao—ning,WU Shao—peng (Institute of Road Engineering,South China University of Technology,Guangzhou 5 10640,P.R China;Key Laboratory for Silicate Materials Science and Engineering of Ministy ofr Education,Wuhan University ofTechnology ,Wuhan 430070,P.R.China) [Abstract] A new type bonding material(polyurethane—aggregates mixture)for bridge deck overlay has been prepared and analyzed.One component moisture—curable polyurethane was chosen for binder material because of its excellent flexibility and durability,and then curing mechanism between polyurethane and aggregates was analyzed then.According to ISSA A143 lI type gradation,polyurethane—aggregate mixture was prepared with selected solidif- ying mechanism.Experimental results of polyurethane—aggregates mixture show[that the materid has]exceHent di— rect tensile and shear properties,fatigue resistance,moisture resistance and flame retardant properties.Polyure— thane—aggregates mixture is proved to be an excellent bonding material for bridge deck oveday due to its exceHent performance. [Key words]polyurethane based curing mechanism catalyzer fatiue propergty
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