道桥专业毕业设计外文翻译----沥青路面

专业外文翻译原文

road surface of pitch

1 Debulk

1.1 Summary

Good pitch road surface quality is it reflect , appear any quality defect will all that has been achieved has come to nothing in rolling through rolling to want. The durable performance of meeting pitch road surface of the structure demand is affected by two indexes mainly, namely the mixture and debulk designed. In these two indexes , lack any durable performance that can't ensure the pitch road surface , if insufficient debulk, optimum mixture that design will reduce serviceability , pitch of road surface, and good debulk can improve the result of a kind of nonstandard mixture effectively . So, debulk is considered to influence one of the most important factors of durable performance of road surface of pitch .

Debulk course to reduce pitch course , air vent of content in the mixture, for solid particle stemming and orientating among one viscoplasticity medium course this, in the form of forming a kind of closely more knit and more effective particle to arrange. This course only takes place under the construction state in theory, but not under the traffic condition.

1.2 Impact on debulk of composition material on the pitch road surface

1.2.1collects material performance

in order to reach the ideal solidity of pressing, it is very important to collect material and detailed some nature of collecting material thickly: Such as the particle form, raised angle , the absorbing water rate and surface are constructed, grade mix mixture most heavy to collect material size , thick to collect material proportion , consumption and type ,etc. , consumption of sand and powder of ore pigeonhole to pitch mixture solidity have direct influence.

Under the same situation as other indexes , collect material one grade of mixture or disconnected grade mixed and mix mixture than exchanging debulk more than the single size from thick to the detailed even grade of mixture mixed , thick to collect

material proportion heavy pitch mixture, must increase the strength of keeping notably , could obtain the necessary space rate . On the other hand, many sand, or detailed grade buy bituminous concrete to be very much easy to be plastic, this kind of mixture is still difficult to reach proper closely knit degree. The pitch mixture of much sand tends towards pushes and shoves and difficult with debulking under debulk function . The different kinds of packing has remarkable influence on debulk of the pitch mixture, according to survey, in a situation that other conditions are the same, ordinary silicate packing than lime stone ore powder pitch mixture and cement stone pitch mixture easy debulk bituminous concrete, pitch mixture total hole rate too very heavy difference have behind the shaping, 8% , 9.1% , 12% respectively.

1.2.2pitch viscidity influence

pitch viscidity influence pitch mixture strength degree, and can debulk nature have something to do with mixture. At the mixture, high viscidity can pin down particle move often as debulk pitch, if pitch viscidity too low, is it collect material to be particle easy to move and push and shove in real time to press. When pitch mixture temperature is higher, pitch is it is it collect material particle rub lubricant of obstruction to overcome to make, when the mixture has already been cooled, the pitch makes and combines the combinationmaterial which is collected the material particle. Generally speaking, in fixed 135 pitch being viscidity high,resistance, mixture of person who reduces space the heavier. So use high viscidity at the pitch , adopt higher debulk temperature to reduce viscidity promote pitch road surface but debulk essential means. Show according to materials data give temperature definitely , low drip of viscidity educate than high closely knit high degree that pitch reach of viscidity, through rise debulk temperature, high viscidity drip is it can reach high solidity of pigeonholing as low viscidity pitch to educate. Therefore understand debulk state , pitch of viscidity under the temperature to promote pitch road surface good debulk there are important meanings.

1.2.3 performance of mixture influence

in fact, performance , pitch of mixture, influence degree, road surface of debulk the heaviest to pitch, the influence than simple to collect material or drip breed

obvious even. When pitch consumption is lower in the pitch mixture easy to is it do astringent , coarse mixture to form, often difficult debulk; When pitch consumption is too great, can form and lubricate the mixture excessivly , make the mixture under the function of the road roller, form unstable and can fracture ing , mixture suffused with the oil after the traffic is open; For lower than best pitch mixture of consumption, can through increase efficiency , debulk of course reduce the space rate, reach a kind of satisfaction; But if pitch consumption at the optimum value of higher thanning , press real-time , can't prevent out of shape limit , pitch of mixture from almost; Secondly , collect material water content meet the requirement of norm minimum while drying, such wet pitch mixture, present the inclination moved in the course of debulk, it is very difficult for the result to press worker.

1.3 Temperature impact on pitch road

surface debulk pitch debulk performance , mixture of road surface receive match ratio design, influence of factor, variety of pitch and temperature ,etc. of debulk, it is the most influential but with debulk temperature. As everyone knows, the properties of pitch and pitch mixture are very sensitive to temperature, is it can know (125C1130 ) in the same grade is it under the mixture , roll rising of temperature at the same time to mix to test. Mixture try on pieces of density increase , air rate reduce , until a certain temperature (145 1150 ) , mixture try on a density up to most heavy, at the same time the air rate is dropped to minimumly . If is it rise to continue under temperature this, can make density reduce, atmosphere rate increases. It is obvious temperature of mixture on the low side on the high side , will influence density and air rate , pitch of mixture (pigeonhole the solidity). The temperature of the pitch mixture is very important too in debulk of the construction site mixture. The temperature of the mixture has already become one of the two major factors influencing the solidity of high pressure of construction site and low air rate. Dark- Kui expressway layers of grains of type in being thick for 4cm the pitch. Construct location windy (4-5), organize the pitch but layer construct in with high temperatures period only, keep temperature bring 80 one 90 up to , make layer receive further debulk the pitch after all.

1.4 mechanical impact on pitch road

Because pitch road surface quality should reflect the mechanical impact on pitch road surface debulk of debulk through rolling finally, so, the selecting type and disposing of debulk machinery seems particularly important. Dark- expressway two bid section (13.4km ) pitch concrete road surface project Kui, construct by Xinjiang the north new construction of road and brige Limited Company, the layers of structure for 6cm thick grains of type grains of grains of type bituminous concrete of the type ten 4cm in the +5cm, the lower floor is the cement stability gravel storey. Each constructed to begin since April of 2000 by the end of September of the same age. Pitch by day work N eight P-1600 for dose rein in 1800 types mix and stir , paver of mixing and stir etc. mixture. According to the regional climate situation of known construction , and mix and stir the productivity of the equipment , paver, transporting the distance and transportation situation, the characteristic of the mixture, pave the thickness, pave layers of location ,etc. , select and make up to the mechanical pattern. Namely use two CC2l a pair of steel and a round of vibration road roller while pressing for the first time , press quietly twice at the speed of 3-5km; When is it press to replying, adopt two CC21 pairs of steel rounds of vibration road roller still, vibration at the speed of 4-5km/11 roll four, dispose the tire road roller of a Model YL16 at the same time, roll twice at the speed of 4-5km/h; After all when pressing, adopt one 2Y8/10 pairs of steel rounds of vibration road roller, at the speed of 3-4km/h quiet to press and accept mere twice. Make from the machinery of the above up and analyse that can be drawn , the having direct relations all over the speed that is counted , rolling with rolling of debulk on the road surface . As thickness , environmental temperature , effective debulk time of paving being when constructing within the person who allow, the ones that rolled would play a decisive role to the debulk of the road surface all over the speed that is counted with rolling.

Can know according to experience. The rolls and only fix through testing section all over countinging of pitch road surface, and should also be in the type of the road roller, solidity of pressing, shake frequently under the situation confirmed of valid debulk time of the amplitude , mixture, could get . Can select through conclusion to

test section to debulk speed at the same time. By result of the test analyse can know , while rolling all over counting the samly , roll slow than roll speed get high solidity of pigeonholing soon, but it is only higher to press the solidity 0.4-0.8, there is no actual use value, while replying and press and press after all, should try one' s best to choose the high speed of rolling , in order to improve and press the mechanical homework efficiency of the way, reduce its quantity allocated

1.5 pitch concrete glue

and form analysis and research VFA (pitch consumption) of strength and pitch kind to solve pitch concrete glued and marries the strength problem. Because Marshall's test method has not already accorded with the actual conditions(because the concrete road surface of pitch has been pressed gently by the automobile tire on the real highway, Marshall test hit real number of times whether two sides each hit 75 times, if increase and hit the real number of times at the same time, aggregate break up and break to pieces, but gentle to press and increase aggregate have broken situation take place even quiet year again), so we must solve with other theory pitch concrete oilstone of as with glueing reason of envelope come and explain pitch concrete oil film thickness of as problem we (oilstone than) problem, we spread certain paste to paste while glueing envelopes, with the increase of the pressure, the surplus paste is crowded out, the tighter the envelope mouth is glued, there is the relation between certain pressure and thickness of the paste, the bigger the pressure is, the thinner the thickness of the paste is, it is the bigger to glue the strength of forming. The thickness of oil film of concrete of pitch is the same too, the greater the pressure of rolling the equipment (the tire) adopted when we construct is, keep high temperature for the first time, oil film thickness thin, pitch concrete that form it glues to be heavy to marry strength, this is that the American engineer JOHN.L.MCRAE gentleman's GTM machine rotates the gentle theory of pressing, this GTM testing machine has well solved the equipment (the pressure of the tire) of rolling, rolls the relation that temperature compares with oilstone (the thickness of the oil film). Seeing that of our country large-scale car amount tire pressure up to 1.0 Mpa more than already, propose and use GTM testing machine go on and rotate with 1.0 pressure of Mpa gentle to pigeonhole, temperature

130 ∽ 135 when testing, after being steady in order to design the amount of oil used with the oil amount. The on-the-spot construction technological requirement is replied and pigeonholes the temperature after finishing to control above 130 degrees, press and adopt the large tonnage tire road roller for the first time (pressure of tires is more than of 1.0 Mpas).

The kind of the pitch and ore material glue the strength of forming influencing the pitch concrete to the seizing of the pitch directly in addition, so the good modified pitch with good resisting splitting at the time of the low temperature at the same time of high-temperature stability has appeared at home, and should deal with the acid and neutral hard quality ore material , improve the seizing, generally adopt and catch the lime wash and is washed or mixed and adds the quick lime powder or low grade cement.

2 Pitch preventative maintenance and machinery of concrete road surface

2.1 The characteristic of concrete road surface of original sin and type of damaging

Pitch because concrete road surface use and glue and form strength better pitch material made and combine the material , therefore gluing the strength of forming while strengthening the ore material greatly , has improved the intensity and stability of the mixture, make to use the quality and durability raise road surface . Pitch concrete road surface have surface level, infiltrate, drive a vehicle advantage comfortable, with low noises, therefore find more and more extensive application. But it is often influenced by respects, such as weather, temperature, driving a vehicle and material, and such reasons of the respect as the road surface structure is designed, will present various disease unavoidably, and the disease has brought harmful influence on driving speed, road surface service life, passenger's comfortableness and traffic safety.

Pitch damage of concrete road surface overall to can be divided into two big classes, one is structural damage , including the destruction of a certain part whole or among them of structure of road surface , the ones that made road surface unable to

support and is scheduled loaded; Another functional damage, it might follow and structural damage take place, but because roughness and resisting the decline in slippery performance,etc. make it not have a function booked again, thus influenced quality of driving a vehicle.

Pitch early disease of concrete road surface show as early rut and decay of roughness, suffused with oil and resist slippery decline of performance often at expressway, show as early small crack at ordinary arterial highway, detailed material lose cause undisguised, polishes, , the host is lost, surface disease that the road surface infiltrates. That the pitch wears out. If disease the can deal with but develop as one pleases in early days, must lead to the fact surface to be loose further, or cause serious deformation disease, such as peeling off and rut of depth of lower floor. Because of infiltrating, then cause structural damage, such as whole trough, thus must adopt the repairing method to carry on road surface maintenance. So seek one swift helping, cost rational settlement pitch concrete road surface early applicable technology of disease to maintain to be solved problem urgently in the work

2.2 Important meaning of preventative maintenance

Around the relation that is built and maintaining, maintaining and preventing, with the constant perfection of the road network, only keep good road surface serviceability for a long time, the huge investment of road construction could give full play to its investment benefit , keep road surface good technological state must have one maintaining and support system come guarantee powerful for a long time, come from this meaning and say , maintain a kind of continuation that is road construction in fact. In the road surface maintains the relation with maintenance, People always get used to it after the road surface begins to be damaged for a long time , just remembers that will carry on maintenance to it, Carry on preventative meaning of maintenance know enough often under being also in good state to road surface. Preventative maintenance is a kind of periodic pressure maintenance measure in fact, it does not consider whether there is a certain damage on the road surface, Preventative maintenance best to implement opportunity should to in good state still in road surface, or go on only at the time of some disease omen .

Though preventative maintenance needs to invest some expenses, it is a kind of expenses- benefit than very good maintenance measure. American department mentions in the road surface solution , what the American road industry was once passed to different grades of hundreds of thousands kilometers is followed, find that the serviceability and life-span of these roads have a common change characteristic : A road with qualified quality, performance drops by 40% within service life 75%, called preventative maintenance stage this stage. Such as be unable to in time maintenance, in 12% service life in the time, performance drops by 40% again afterwards, cause and maintain cost increase by a large margin , call that and correct maintenance stage this stages. Count and draw and invest through investigation 1 preventative maintenance fund can economize 3- l0 yuan correct maintenance conclusion of fund each time. U.S.A. SHRP plan one important achievement point out preventative maintenance delay road surface serviceability worsen the speed, lengthen its service life and economize the important meaning of expenses of life cycle.

Correct serviceability that implement preventative maintenance and can keep the road surface good , lengthen life cycle of road surface , reduce life cycle expenses and economize and maintain the fund. Plan and estimate according to SHRP , go on preventative maintenance of 3-4 can lengthen 10- 1 years such as service life within life cycle of whole road surface, economize and maintain 45-50% of expenses, these foreign experience of benefitting is worth we drew lessons from . Need emphasize , implement to one- two road preventative maintenance can not give full play to his potential benefit and function only, put it preventative maintenance in network of highways support height of the system pay only, could fully embody its important strategic meaning and function .

2.3 Choose suitable preventative maintenance machinery

Carry on maintenance promptly when the road surface presents disease omen , make it not happen or continue developing, expanding , influence the stability of the basic unit, should carry on preventative maintenance. Preventative maintenance capital equipment have and irritate and sew machinery, road surface part mend homework machinery, heavy area surface punish machinery, usually.

The pressure type irritates the sewing machine: Adopt artificial way to irritate and sew the homework, though can prevent the infiltration of the sub-surface of rainwater , alleviate the development with further crack, but because the sealed material is not irritated deeply enough, it is very difficult to reach the lasting result. Adopt pressure type irritate person who sew can irritate deep layer to reach the crack sealed material, irritate and sew better result , can lengthen service life of road surface , raise and go the security and comfortableness of the vehicle.

Irritate and sew homework want and carry on clear to go on and irritate and sew after sewing first generally, greater than 3 crack of mm need and slot the homework generally. Irritate the heating that the sewing machine should be furnished with the control device of pressure, sealed material mainly or keep the device warm, for prevent spray gun hose from stop up and should take corresponding heating, keep measure warm also. The main characteristic of the pulling type is: Heat storehouse volume 470L, relatively more complete function havesuitable for irritating and sewing the homework by a large scale. Pair set up yuans of hand person who push away hot to irritate heating storehouse of person who sew volume 40 L, small easy to operate using flexible, low fabrication cost company, can look at according to work load feeling worthy of and heat cauldron again separately, suitable for hot to caulk the irritating and sewing the homework of material mainly; Have function cold to irritate person who sew without heating, use polymer modify water quality caulk the material mainly. If department pitch cold to irritate and sew material to modify emulsification, as emulsification after the solidification pitch, the modified pitch and crack of high polymer are glued and formed closely, can guarantee that there is good strength of seizing to irritate and sew the material and crack . Because cold to irritate and sew simple, easy to use craft, road surface give person who defend maintenance have wide prospects in pitch.

Mend the hole machine in spraying type: Person who spray pitch road surface mend technology one high-efficient mending road surface hole maintenance technology of pool fast, cardinal principle to utilize way of spaying with high presure , mix emulsification pitch that heat already through nozzle with conveyer belt dept. of

orthopedics come to convey, spray the mixture to the hole pool of road surface evenly through the compressed air at a high speed, because passing through function reaches and glues the result formed closely knitly. Because craft simple, need and go on and roll again, mend hole short activity duration, can open traffic quickly.

Hope that you remember my result every day. Car chassis (or pulling type); Pitch pot of emulsification and heating and keep the device warm, sending the pipeline; The aggregate stores the storehouse and conveyer belt; The cleaner stores the pot; Liquor pressure drive; Air compressor machine and nozzlemake up . In pool go on and clear up, after repairing, attenbant need and know one nozzle (operate button at nozzle handle) can finish the hole pool of road surface mend the homework only to hole. Should pay attention to controlling the quality of the good aggregate and grading in using; Choose the broken milk tempo of the good emulsification pitch ; Grasp the spraying amount and so as to ensure roughness of road surface after mending, Mend machinery in hot regeneration of road surface : For economize valuable way spend material, reduce and mill old material pollution of the environment these come down to plane, many place popularize old way spend regeneration of material, pitch hot recycled craft because with cold to mill- factory mix recycled craft compare on the spot among them in a more cost-effective manner, reduce old material freight and factory mix regeneration need use continuous type to mix and stir the reasons, such as equipment. Generally, the maintenance of the expressway is widely used with maintaining in JiangsuProvince. Reach materials that company offer according to Great Britain, " repair the roads king " its mend method compare with traditional method, it can save 5/6 to mend time, personnel save 1/2 for homework, the old way totally utilizes with the material, new pitch mixture consumption can save 1/2 .

Hot recycled key part of equipment to heat board mainly on the spot, it want offer high-efficient heat energy of radiating, heat and should short time to old road surface have, and reach certain depth; Can't be overheated, make the pitch wear out , lose the recycled meaning. Great Britain reach company repair the roads king heat board take interval heating way, can one is penetrated to the road surface deep layer, and road surface top layer pitch wear out again and hotly, well solve this problem . In

addition according to mend area of uniform size, heat board it's better to have the sub-zone function.

The rare thick liquid seals one layer of pitch rare thick liquid of emulsification with modifying and seals one layer of pavers: Rare thick liquid seal layers of technology to new, old wear out, crack, smooth loose of road surface, hole trough. Disease can play prevent and function of maintenance, make road surface waterproof, resist slippery, levels, wear-resisting performance is raised rapidly. In recent years, because rare thick liquid seal layers of standardization that construct, standardize, construction quality raise and reducing of cost, rare thick liquid seal layer apply common road and expressway maintained and had in early days extensively already.

Modify emulsification pitch rare thick liquid seal layer modify emulsification pitch with roll and break to pieces by water quality high polymer intensive material, mineral packing, water and surface that additive make up punish layer one, can pave the thin layer , solidify fast, can open traffic in an hour after constructing in characteristic, because modify the pitch rare thick liquid of emulsification seal one layer of solidification time faster than the ordinary rare thick liquid, modify emulsification pitch rare thick liquid seal layer can seal than traditional rare thick liquid layer thick. Used in the punishment of constructing disease, such as repairing, chap, rut, etc. of road surface mainly, can be used for sealing and improving resisting slippery punishment of road surface. But modify the pitch rare thick liquid of emulsification is the same as other thin layers are punished, only have highway section with steady structure now suitably, must construct after mending strongly when curved sinking value is not enough. Guarantee modify emulsification pitch there aren't the thick liquid not rares. Modify emulsification pitch rare thick liquid material viscidity heavy, pave layer relatively thick, generally speaking, modify emulsification pitch raise than the emulsification pitch viscidity not modifying by 30-50%, result in and make obstruction heavy thick liquid, the speed slows down. Demand and modify emulsification pitch rare thick liquid seal layers of equipment device corresponding to strengthen power store to make thick liquid, cloth fast, mobility fine, cloth speed pave range that the thickness regulate heavy, in order to meet modifying the construction

request for sealing layer of rare thick liquid of pitch of emulsification.

The pitch road surface maintains machinery and cares the car synthetically, cares the car etc. multi-functionally, have given play to one's own characteristics in the maintenance of the superhighway. As the constant increase,, especially the expressway of the superhighway increase, and the constant innovation on maintenance work craft and material , the mechanical manufacturer to maintaining , including the respects, such as designing, making, after-sale service. Put forward higher and higher request. Too should maintain mechanical applying unit from maintenance, quality of attenbant of equipment, maintenance exertion of material,etc. pays enough attention, it is in many aspects to accomplish, multi-disciplinary close cooperation, could promote the preventative maintenance mechanized development of the highway to the maximum extent .

3 pitch concrete road surface in constructing

1.one of precautions infiltrate, design and grade kind pitch concrete match ratio very in theory in constructing, in not butting if can't construct it guarantee by pitch concrete homogeneity(include and grade and last homogeneity that shut pitch , homogeneity that pave, roll homogeneity of shaping), pitch concrete road surface equally will produce infiltrate, purt thick liquid, rut, suffused with oil,etc. destroy the phenomenon in early days. Stone fit expressway pitch concrete finish adopt many broken stone pitch concrete (SAC) make finish structure, SAC structure does not infiltrate theoretically, and have good resisting the slipping and temperature stability, can meet and construct TD of depth > request for 0.7mm, why is it very good in some paragraphs on the line of Ann of stone, some paragraph very serious to destroy phenomenon in early days, main reason to guarantee pitch concrete homogeneity of road surface and pigeonhole solidity, pursue the roughness to cause excessivly. Guarantee pitch homogeneity of concrete and pigeonhole solidity key problem very in constructing. Sand celebrate academician Lin in " expressway pitch road surface destroy phenomenon with predict " book chapter ten describe to pitch concrete importance of homogeneity specially " in early days. Only brief here to sum up the

following several points.

2. Pitch concrete that cause in constructing it emanates to be in many aspects , celebrate book of academician Lin already discussed a lot in sand, the supplementary formsing when pave in the course and emanates here will be caused and pay close attention to , pave and can dispel and pave with two 6 wide ABG423 course grade and emanate and temperature emanate basically, if pave a ABG paver 12 meters wide, it is very serious that the ones that paves course are emanated, a lot of countries forbid paving the concrete road surface of pitch with the paver 12 meters wide.

3. Control layers of oil completely and glue layers of homogeneity and very much important amount of oil spent of oil strictly, if person who uses oil too much and also even, surplus layers of oil glue layers of oil permeate and get pitch among the concrete completely, cause pitch pitch of concrete consumption heavy in fact, road surface appear suffused with oil and phenomenon of rut.

4.Control the solidity of pressing strictly: Guarantee that the absolute space rate of the pitch concrete is smaller than 7%, could guarantee that the concrete road surface of pitch does not infiltrate . Want the high temperature to be rolled while constructing, should make sure that it is not lower than 130 ° Cs to reply the pitch concrete road surface temperature after finishing pressing, want and adopt large tonnage rubber tyer road roller pigeonhole for the first time keep solidity result very much obvious improving, the road roller high temperature of the rubber tyer is rolled and guaranteed that the detailed material packs space and thick aggregate to arrange in an order rationally, and have obvious results to construct the depth in improving the surface.

专业外文翻译译文

沥青路面

1 压实

1.1 概述

良好的沥青路面质量要通过碾压来体现，如果碾压中出现任何质量缺陷必将前功尽弃。满足结构要求的沥青路面的耐用性能主要受两个指标的影响，即设计的混合料和压实。在这两个指标中，缺少任何一个都不能保障沥青路面的耐用性能，如果不充分压实，最优设计的混合料都会降低沥青路面的使用性能，而良好压实能有效地改进一种不标准的混合料的结果。因此，压实被认为是影响沥青路面耐用性能最重要的因素之一。

压实过程是减少沥青混合料中气孔含量的过程，此过程为固体颗粒在一种粘弹性介质中的填实和定位，以形成一种更密实和有效的颗粒排列形式。理论上这一过程只发生在施工状况下，而不是交通条件下。

1.2沥青路面的组成材料对压实的影响

1.2.1集料性能

为了达到理想的压实度，粗集料及细集料的一些性质是非常重要的：如颗粒形状、棱角、吸水率和表面构造，级配混合料的最大集料尺寸、粗集料比例、砂用量、矿粉用量和类型等对沥青混合料的压实度都有直接影响。

在与其它指标相同的情况下，从粗到细均匀级配的混合料比单一尺寸集料级配的混合料或间断级配混合料较易压实，粗集料比例大的沥青混合料，必须显著增大压实力，才能获得所需空隙率。另一方面，多砂的或细级配沥青混凝土极易可塑，这种混合料仍难以达到适当的密实度。多砂的沥青混合料在压实作用下趋于推挤且难以压实。

不同类型的填料对沥青混合料的压实有显著的影响，据实测，在其它条件相同的情况下，普通硅酸盐填料沥青混凝土比石灰石矿粉沥青混合料和水泥石沥青混合料易于压实，成型后沥青混合料总孔隙率相差也很大，分别为8％、9.1％、12％。

1.2.2沥青粘度影响

沥青粘度影响沥青混合料劲度，并与混合料的可压实性有关。当压实沥青混合料时，高粘度往往会牵制颗粒移动，如果沥青粘度太低，压实时集料颗粒容易移动和推挤。当沥青混合料温度较高时，沥青充当克服集料颗粒间摩阻力的润滑剂，在混合料已冷却时，沥青充当结合集料颗粒的结合料。

一般来说，在规定的135℃沥青粘度越高，混合料减少空隙率的抵抗力越大。因此，使用高粘度沥青时，采用较高的压实温度是减少粘度促进沥青路面可压实的必要手段。据资料数据显示，在给定的温度下，低粘度的沥育比高粘度的沥青达到的密实度更高，通过升高压实温度，高粘度沥育能达到与低粘度沥青一样高的压实度。由此可见，了解压实温度下沥青粘度的状态对促进沥青路面良好的压实有重要意义。

1.2.3混合料的性能影响

事实上，沥青混合料的性能，对沥青路面压实的影响程度最大，这种影响甚至比单纯集料或沥育更明显。

当沥青混合料中沥青用量较低时易形成干涩、粗糙的混合料，往往难于压实；当沥青用量太大时，可形成过度润滑混合料，使混合料在压路机作用下，形成不稳定且可开裂、交通开放后泛油的混合料；对于低于最佳沥青用量的混合料，可以通过增加压实过程的效率来减少空隙率，达到一种满意程度；但如果沥青用量高于最佳值时，在压实时，几乎不能防止沥青混合料的极限变形；其次，如果集料在烘干时含水量未达到规范最小值的要求，这种湿的沥青混合料，在压实过程中呈现移动的

倾向，结果也很难进行压实施工。

1.3温度对沥青路面压实的影响

沥青混合料路面的压实性能受配合比设计、沥青品种、压实温度等因素的影响，但是以压实温度的影响最大。众所周知，沥青和沥青混合料的性状对温度非常敏感，由试验可知，在相同级配混合料下，随碾压温度的升高(125C一130℃)．混合料试件密度增大，空气率减少，到某一温度时(145℃一150℃)、混合料试件密度达到最大，同时空气率降到最小．如在此温度下继续升高，则会使密度减少，空气率增大。可见混合料的温度偏低和偏高，都会影响沥青混合料的密度和空气率(压实度)。沥青混合料的温度对施工现场混合料的压实同样非常重要。混合料

的温度已经成为影响施工现场高压实度和低空气率的两大因素之一。乌—奎高速公路沥青面层为4cm厚中粒式．而且施工地段多风(4—5级)，只有在气温较高的时段内组织沥青而层施工，且将终压温度提高到80℃一90℃，使沥青面层得到进一步的压实。

1.4压实机械对沥青路面压实的影响

因沥青路面质量最终要通过碾压来体现，所以，压实机械的选型及配置显得尤为重要。

乌—奎高速公路二标段(13．4km)沥青混凝土路面工程，由新疆北新路桥建设股份有限公司施工，其面层结构为6cm粗粒式+5cm中粒式十4cm中粒式沥青混凝土，下层为水泥稳定砂砾层。面层施工自2000年4月开始到同年9月结束。沥青混合料由日工N八P—1600型拌和机拌和、摊铺机为弗格勒1800型。根据已知的施工区域气候情况，以及拌和设备、摊铺机的生产率，运距和运力情况，混合料的特性，摊铺厚度，摊铺层位等，对机械型式进行了选定和组合。即初压时用两台CC2l双钢轮振动压路机，以3-5km儿的速度静压两遍；复压时，仍采用两台CC21双钢轮振动压路机，以4-5km／11的速度振动碾压四遍，同时配置一台YL16型轮胎压路机，以4-5km／h的速度碾压两遍；终压时，采用一台2Y8／10双钢轮振动压路机，以3-4km／h的速度静压收光两遍。

从以上的机械组合分析可以得出，路面的压实与碾压的遍数、碾压的速度有直接的关系。当摊铺厚度、环境气温、有效压实时间均在施工允许值以内时，碾压的遍数与碾压的速度对路面的压实将起决定作用。

根据经验可知．沥青路面的碾压遍数只有通过试验段来确定，而且还应在压路机类型、压实度、振频振幅、混合料的有效压实时间确定的情况下，才能获得。同时也可以通过试验段的结论对压实速度进行选定。由试验结果分析可知，在碾压遍数相同时，碾压速度慢比碾压速度快要得到更高的压实度，但压实度也只高出0.4-0.8，无实际使用价值，所以在复压和终压时，应尽量选择高的碾压速度，以提高压路机械的作业效率，并减少其配备的数量。

1.5 沥青砼粘结力的影响

研究VFA（沥青用量）和沥青种类是解决沥青砼粘结力问题。由于马歇尔试验方法和实际情况已经不符（因为实际公路上沥青砼路面受汽车轮胎柔压，同时

马歇尔试验击实次数是两面各击75次，如再增加击实次数，骨料就被击破碎了，而柔压再增加静载骨料也没有破碎情况发生），所以我们必须用其它理论来解决沥青砼油石比问题

我们用粘信封的道理来解释沥青砼油膜厚度（油石比）问题，我们粘信封时涂上一定的浆糊进行粘贴，随着压力的增大，多余的浆糊被挤出来，信封口粘的就越紧，一定的压力和浆糊的厚度是有关系的，压力越大，浆糊的厚度越薄，粘结力也就越大。沥青砼油膜厚度也是一样，当我们施工时采用的碾压设备（轮胎）的压强越大，初压温度越高，油膜厚度越薄，形成的沥青砼粘结力也就越大，这就是美国工程兵JOHN.L.MCRAE先生的GTM机旋转柔压理论，该GTM试验机很好地解决了碾压设备（轮胎压强）、碾压温度和油石比（油膜厚度）的关系。鉴于我国大型车量轮胎压强已达到1.0Mpa以上，所以建议使用GTM试验机用1.0Mpa的压力进行旋转柔压，试验时温度为130∽135度，稳定后的用油量为设计用油量。现场施工工艺要求复压完成后的温度控制在130度以上，初压采用大吨位轮胎压路机（轮胎压强为1.0Mpa以上）。

另外沥青的种类及矿料对沥青的粘附性也直接影响着沥青砼粘结力，所以国内出现了高温稳定性好同时低温时具有良好的抗裂性的改性沥青，并且要对酸性的和中性的硬质矿料要进行处理，提高粘附性，一般采用生石灰水清洗或掺加生石灰粉或低标号水泥。

2 沥青混凝土路面预防性养护与机械

2.1 沥青混凝土路面特点及损坏类型

沥青混凝土路面由于使用粘结力较强的沥青材料作结合料，因而大大增强了矿料间的粘结力，提高了混合料的强度和稳定性，使路面的使用质量和耐久性得到提高。沥青混凝土路面具有表面平整、不渗水、行车舒适、噪音小等优点，因而获得越来越广泛的应用。但它也经常受到天气、温度、行车以及材料等方面的影响，以及路面结构设计等方面的原因，不可避免地会出现各种各样的病害，而这些病害又对行车速度、路面使用寿命、乘客舒适性以及交通安全等带来了有害的影响。

沥青混凝土路面的损坏总体可分为两大类，一类为结构性损坏，包括路面结构整体或其中某一部分的破坏，使路面不能支承预定的荷载；另一类为功能

性损坏，它可能不伴随结构性损坏而发生，但由于平整度和抗滑性能等的下降，使其不再具有预定的功能，从而影响了行车质量。

沥青混凝土路面的早期病害在高速公路上常常表现为早期车辙和平整度的衰减、泛油和抗滑性能的下降，在普通干线公路上则表现为早期的微小裂缝，细料失落导致的露骨、磨光，沥青老化、基质损失、路面渗水等表面病害。这些病害如不能在早期处理而任其发展，则必然进一步导致表面松散，或由于渗水而导致下层剥落以及深度车辙等严重的变形类病害，继而造成坑槽等结构性损坏，从而必须采用修复性的方法来进行路面维修。因此，寻求一种快捷、方便、成本合理的解决沥青混凝土路面早期病害的适用技术是养护工作中亟待解决的问题。

2.2 预防性养护的重要意义

围绕建设与养护、维修与预防的关系，随着路网的不断完善，只有长期保持良好的路面使用性能，公路建设的巨额投资才能充分发挥其投资效益，而长期保持路面良好的技术状况必须有一个强有力的养护维修支持系统来保障，从这一意义上来说，养护维修实际上是公路建设的一种继续。在路面养护和维修的关系上，长期以来人们总是习惯于等到路面开始出现损坏后，才想起要对它进行维修，而对于路面还处于良好状态下进行预防性养护的意义则往往认识不足。预防性养护实质上是一种周期性的强制保养措施，它并不考虑路面是否已经有了某种损坏。预防性养护最佳实施时机应该是在路面尚处于良好状况，或者只有某些病害先兆时进行。虽然预防性养护需要投入某些费用，但它是一种费用—效益比非常良好的养护措施。美国科氏路面解决方案中提到，美国道路业曾通过对几十万公里不同等级道路的跟踪，发现这些道路的使用性能和寿命有一个共同的变化特征:一条质量合格的道路，在使用寿命75%的时间内性能下降40%，这一阶段称之为预防性养护阶段。如不能及时养护，在随后12%的使用寿命时间内，性能再次下降40%，从而造成养护成本大幅度的增加，这一阶段称之为矫正性养护阶段。并通过调查统计得出每投入1元预防性养护资金可节约3-l0元矫正性养护资金的结论。美国SHRP计划一个重要成果就是指出了预防性养护在延缓路面使用性能恶化速率、延长其使用寿命和节约寿命周期费用方面的重要意义。正确实施预防性养护可保持路面良好的使用性能，延长路

面的使用周期，减少寿命周期费用和节约养护维修资金。根据SHRP计划估算，在整个路面寿命周期内进行3-4次的预防性养护可以延长使用寿命10- 15年，节约养护费用45-50%，这些国外的有益经验是值得我们借鉴的。需要强调的是，仅仅对一、二条道路实施预防性养护并不能充分发挥其潜在的效益和作用，而只有将它置于公路网的预防性养护支持体系的高度上，才能充分体现出它的重要战略意义和作用。

2.3 选择合适的预防性养护机械

在路面出现病害先兆之时即进行养护，使其不发生或不继续发展、扩大，影响到基层的稳定，就应该进行预防性养护。通常预防性养护主要设备有灌缝机械、路面局部修补作业机械、大面积表面处治机械等。

压力式灌缝机：采用人工的方式进行灌缝作业，虽然可以防止雨水对路面基层的渗透，缓解裂缝进一步的发展，但由于密封材料灌得不够深，很难达到持久的效果。而采用压力式灌缝机则可将密封材料灌到裂缝的深层，灌缝效果较好，能延长路面的使用寿命，提高行驶车辆的安全性与舒适性。

灌缝作业前一般先要进行清缝后再进行灌缝，大于3mm的裂缝一般还需要开槽作业。灌缝机主要应配有压力控制装置、密封材料的加热或保温装置，为防止喷枪软管堵塞还应采取相应的加热、保温（如缠绕电热带等）措施。拖挂式的主要特点是：加热仓容积为470L，功能较齐全，适用于大面积灌缝作业。双立元公司手推式热灌缝机的加热仓容积为40L，体积小、操作方便、使用灵活、造价低，并可根据工作量视情另增配加热釜，主要适用于热填缝料的灌缝作业；还有不带加热功能的冷灌缝机，主要使用聚合物改性水质填缝料。如科氏改性乳化沥青冷灌缝料，当乳化沥青固化后，高分子改性沥青与裂缝紧密粘结，能保证灌缝料与裂缝有良好的粘附力。由于冷灌缝工艺简单，使用方便，在沥青路面预防性养护中具有广阔的前景。

喷射式补坑机：喷射式沥青路面修补技术是一种高效、快速修补路面坑塘的养护技术，主要原理是利用高压喷射方式，将已加热的乳化沥青经过喷管与输送带传送来的骨科相混合，通过高速压缩空气将混合料均匀地喷射到路面坑塘中，由于贯性的作用达到密实粘结的效果。由于工艺简单，又无需再进行碾压，补坑作业时间短，能很快开放交通。