土木工程材料第五章1ppt课件

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1、Ch5 Bituminous Materials5.1 Types of asphalt5.2 Petroleum asphalt5.3 Properties of asphalt5.4 Asphalt grades5.5 Spray applications5.6 Testing 5.1 Types of asphaltBitumen is a solid，semisolid，or viscous cementitious material，natural or manufactured，and composed principally of various mixtures of comp

2、lex hydrocarbons(烃,碳氢化合物).Features of bitumenCompletely soluble in carbon disulfide(CS2)NonvolatileSoften when heated沥青分类沥青分类沥青资料分为地沥青和焦油沥青两大类。沥青资料分为地沥青和焦油沥青两大类。地沥青又分为天然沥青和石油沥青地沥青又分为天然沥青和石油沥青天然沥青是石油渗出地表经长期暴露和蒸发后天然沥青是石油渗出地表经长期暴露和蒸发后的残留物；的残留物；石油沥青是将精制加工石油所剩余的渣油，经石油沥青是将精制加工石油所剩余的渣油，经适当的工艺处置后得到的产品。适当的工艺

3、处置后得到的产品。焦油沥青是煤、木材等有机物干馏加工所得的焦油沥青是煤、木材等有机物干馏加工所得的焦油经再加工后的产品。焦油经再加工后的产品。工程中采用的沥青绝大多数是石油沥青，石油工程中采用的沥青绝大多数是石油沥青，石油沥青是复杂的碳氢化合物与其非金属衍生物组沥青是复杂的碳氢化合物与其非金属衍生物组成的混合物。通常沥青闪点在成的混合物。通常沥青闪点在240330之之间，燃点比闪点约高间，燃点比闪点约高36度，因此施工温度，因此施工温度应控制在闪点以下。度应控制在闪点以下。地沥青地沥青石油沥青石油沥青沥青膏沥青膏焦油沥青焦油沥青焦油焦油天然沥青天然沥青天然沥青天然沥青岩石沥青岩石沥青乳化沥青乳

4、化沥青稀释稀释(石油石油)沥青沥青氧化沥青氧化沥青慢凝慢凝中凝中凝快凝快凝沥青烃沥青烃,碳氢化合物碳氢化合物Uses of bituminous materialsBitumens possess a number of properties that make them useful in the constructionability to adhere to solid particles impermeability or water resistanceUses of bituminous materials roadways pavementsmany construction p

5、roductssuch as roofing felt,caulking compound,waterproofing compounds,wallboard,building paper,paints,etc.waterproof coatings for walls and below-grade structures5.1.1 Tars and pitchesTars,along with pitches,are the products of distillation of materials such as wood,coal,and shale.When these materia

6、ls undergo destructive distillation,the resulting condensate冷凝物 is tarFurther processing yields a solid or semisolid residue known as pitchTar 焦油Generally by-product of coke(from coal)productionWhen coal is heated in coke ovens,it is reduced to coke.The gases(vaporized oils)generated during the proc

7、ess are collected from the oven and refined.The distillation of lighter oils produces tar.焦油是煤炭在焦化过程中产生的。其产量约占装炉煤的3%4%，在常温常压下其产品呈黑色粘稠液状，密度通常在0.95-1.10g/cm3之间，焦油又称煤焦油。Tar pitches 焦油沥青Tar pitches are used for built-up roofing and waterproofing of underground and aboveground constructionsuch as foundat

8、ions，retaining walls，dams，and bridgesAboveground structures experience great fluctuations in environmental conditions，and waterproofing compounds should be able to withstand these changes without becoming brittle or too soft5.1.2 AsphaltsAsphalts are cementitious materials in which the predominant c

9、onstituent materials are bitumens.Natural deposits or petroleum asphaltThe consistency of asphalts varies widely from solid to semisolid at normal temperatureThe natural deposits of asphalts are of two types：Natural rock asphaltsDeposits of sandstone or limestone filled with asphaltsNative asphalts

10、or lake asphaltsLake Trinidad特立尼达岛，West Indies(a 110-acre lake containing about 40 percent bitumen mixed with water,fine siliceous silt,clay,and organic matter);Bermudez，Venezuela(lake asphalt containing about 65 percent bitumen)Trinidad Lake Asphalt特立尼达岛特立尼达岛 imgsrc.baidu/baike/pic/item/9319cf098da

11、1cf91d1581bb7.jpg的主岛。与委内瑞拉东北部海岸相望，最近处仅的主岛。与委内瑞拉东北部海岸相望，最近处仅11公里。面积公里。面积4，828平方公里。人口平方公里。人口101.6万万1980。1532年起沦为西班牙年起沦为西班牙殖民地，后被英、荷、法侵占，殖民地，后被英、荷、法侵占，1802年成为英国殖民地。年成为英国殖民地。1962年独立后成为该国领土的主要部分。岛上北部、中部、南部有三年独立后成为该国领土的主要部分。岛上北部、中部、南部有三条大致东西向的低山脉，最顶峰为北部山脉的阿里波山条大致东西向的低山脉，最顶峰为北部山脉的阿里波山940米。向南地势降低，大部分地方为不超越米

12、。向南地势降低，大部分地方为不超越150米的低平原。沿米的低平原。沿海多沼泽。热带气候，炎热潮湿，有干季。河流短促、经济以石海多沼泽。热带气候，炎热潮湿，有干季。河流短促、经济以石油工业为主。南部石油带面积约油工业为主。南部石油带面积约2，000平方公里及沿海大平方公里及沿海大陆架富藏石油和天然气，西南部有出名世界的沥青湖。炼油才干陆架富藏石油和天然气，西南部有出名世界的沥青湖。炼油才干超越开采才干，主要炼油中心和石油输出港是皮埃尔角、福廷角超越开采才干，主要炼油中心和石油输出港是皮埃尔角、福廷角和拉布雷阿，均在西南部帕里亚湾岸。农作区主要分布在中部平和拉布雷阿，均在西南部帕里亚湾岸。农作区主

13、要分布在中部平原，甘蔗为传统经济作物。原，甘蔗为传统经济作物。*5.2 Petroleum asphaltPetroleum asphalts are classified into four types：Asphalt cementsCutback asphaltsEmulsified asphaltsAir-blown asphaltsUsages of petroleum asphalts Petroleum asphalts are used in construction of flexible pavementsroof construction(asphalt shingles,

14、rolled roofing,and built-up roofing),for insulation(electrical insulation and building paper)waterproofing(sprays,paints,and bituminous fabrics)canal lining seal subgrades against the migration of waterJoint seals*5.2 Petroleum asphaltPetroleum asphalts are classified into four types：Asphalt cements

15、Cutback asphaltsEmulsified asphaltsAir-blown asphalts5.2.1 Asphalt CementAsphalt cement is very sticky and highly viscous,especially prepared with the quality and consistency required in the manufacture of asphalt pavements(hot-mix pavements).It is obtained after separation of lubricating oils from

16、crude petroleum.Properties of asphalt cement It possesses excellent binding properties and adheres very well to aggregate particles.when used in pavement construction it is necessary to heat both the asphalt cement and the aggregates prior to mixingsuperior waterproof qualitiesPavement built using p

17、aving asphalt is waterproof and resistant to many types of chemical attack.*5.2 Petroleum asphaltPetroleum asphalts are classified into four types：Asphalt cementsCutback asphaltsEmulsified asphaltsAir-blown asphalts5.2.2 Cutback Asphalts Two types of asphalt are available in liquid form:cutback asph

18、alt emulsified asphaltCutback asphalt-is asphalt cement that is liquefied by blending with petroleum solvents(called diluents).Cutback asphalt are divided into three typesSlow-curingMedium-curingRapid-curing Slow-curing cutback asphaltSlow-curing cutback asphalt is asphalt cement blended with oils o

19、f low volatility，such as diesel oil 柴油.Its viscosity value is low and it hardens very slowly.It is used for cold laid pavement bases.Medium-curing cutback asphaltMedium-curing cutback asphalt is obtained by blending asphalt cement with kerosene-煤油 type diluents of medium volatility.It hardens faster

20、 than the slow-curing and slower than the rapid-curing type.Used for cold-laid pavement bases(plant mixed and mixed in place)and surface treatmentsRapid-curing cutback asphaltRapid-curing cutback asphalt is asphalt cement blended with naphtha or gasoline-汽油 type diluents of high volatility.The dilue

21、nts in rapid-curing asphalt evaporate quickly.Used primarily in mixed-in-place pavement mixes and surface treatments.*5.2 Petroleum asphaltPetroleum asphalts are classified into four types：Asphalt cementsCutback asphaltsEmulsified asphaltsAir-blown asphalts5.2.3 Emulsified AsphaltEmulsified asphalt

22、is composed of asphalt cement and water that contains a small amount of an emulsifying agentSoapswater-soluble chemicalsfine clay乳化沥青乳化沥青 乳化沥青是将通常高温运用的道路沥青，经过乳化沥青是将通常高温运用的道路沥青，经过机械搅拌和化学稳定的方法乳化，分散到机械搅拌和化学稳定的方法乳化，分散到水中而液化成常温下粘度很低、流动性很好的水中而液化成常温下粘度很低、流动性很好的一种道路建筑资料。可以常温运用，且可以和一种道路建筑资料。可以常温运用，且可以和冷的和潮湿的

23、石料一同运用。冷的和潮湿的石料一同运用。当乳化沥青破乳凝固时当乳化沥青破乳凝固时-复原为延续的沥青并复原为延续的沥青并且水分完全排除掉，道路资料的最终强度才干且水分完全排除掉，道路资料的最终强度才干构成。、构成。、在众多的道路建立运用中，乳化沥青提供了一在众多的道路建立运用中，乳化沥青提供了一种比热沥青更为平安、节能和环保的系统，由种比热沥青更为平安、节能和环保的系统，由于这种工艺防止了高温操作、加热和有害排放。于这种工艺防止了高温操作、加热和有害排放。乳化沥青主要用于道路的晋级与养护，如石屑乳化沥青主要用于道路的晋级与养护，如石屑封层，还有多种独特的、其它沥青资料不可替封层，还有多种独特的、

24、其它沥青资料不可替代的运用，如冷拌料、稀浆封层。乳化沥青亦代的运用，如冷拌料、稀浆封层。乳化沥青亦可用于新建道路施工，如粘层油、透层油等。可用于新建道路施工，如粘层油、透层油等。*advantages of emulsified asphaltemulsified asphalt can be applied during damp weather and with aggregates that are cold or hotthe quantity of materials applied is controlled automatically because any excess(wat

25、er)will drain into the subgradesaving energyThe use of emulsified asphalt also eliminates the use of fuel required to heat and dry the aggregates in the asphalt cement mixturesreduces energy requirements through reduction or elimination of petroleum distillates used in cutback asphalts.*disadvantage

26、 of emulsified asphaltpollutionbecause the asphalt is suspended in water,it is susceptible to being washed off a road surface by rainwater if not sufficiently cured.The unbroken emulsions may be carried into streams,causing ground contamination.*5.2 Petroleum asphaltPetroleum asphalts are classified

27、 into four types：Asphalt cementsCutback asphaltsEmulsified asphaltsAir-blown asphalts5.2.4 Blown AsphaltBlown asphalt is obtained by blowing air through the semisolid residue obtained during the later stages of the distillation processProperties relatively firm in consistency Ductileweather resistant and can withstand temperature changes very wellUsages of Blown asphaltsBlown asphalts use in the manufactureroofing materialswaterproof paints joint fillers(for concrete pavements)undersealing old，rigid pavements mineral rubber