首页
登录
职称英语
[originaltext]Mr. Jones: What materials were used for road surfaces during the
[originaltext]Mr. Jones: What materials were used for road surfaces during the
游客
2023-12-08
53
管理
问题
Mr. Jones: What materials were used for road surfaces during the last century?
Engineer: Usually they were gravel and macadam. Tars and asphalt were originally used only as coverings, but later they were used as binders and finally as hot mixtures.
Mr. Jones: Concrete is a modem material as far as road building goes, isn’t it?
Engineer: Relatively speaking. But you might be surprised to know that a concrete road was built as early as 1893 in Ohio. But it was only 5 miles long. More extensive projects were not undertaken until much later, round 1912 or 1913.
Mr. Jones: This was because of the increase in traffic?
Engineer: That’s fight. Especially in the use of heavy tracks. More rigid pavements, such as concrete and brick, became a necessity. For light traffic, though, water-bound macadam, gravel, sand clay, and bituminous mixtures were still used.
Mr. Jones: What are turnpikes usually made of?
Engineer: Turnpikes are usually made of reinforced concrete about 8 to 10 inches thick, placed on a granular sub-base, which in turn is placed on a well -tacked earth subgrade. Of course, the construction depends a lot on the local climate, rainfall, soils, and so on.
Mr. Jones: How do you mean--climate?
Engineer: Frost is one of the main problems. For example, in Maine, where frost is quite frequent, the typical turnpike construction is a thin top layer of asphaltic concrete on a base layer of sand and gravel placed on a 36 - inch, frost - free, granular subgrade.
Mr. Jones: What is the width of these roads?
Engineer: The early two -lane roads were about 20 feet wide. But with higher automobile speeds, the width requirements increased greatly. To give you an ex-ample, the Pennsylvania Turnpike has two 12 -foot lanes in each direction, separated by a median 10 feet wide. On each side there is a 10 -foot stabilized shoulder, marking a total width of 78 feet. The New Jersey Turnpike averages 100 feet in width, with three lanes in each direction.
Mr. Jones: I guess wider roads are being built every day.
Engineer: That’s right. Sometimes you think that, no matter how good a road you build, the speed and weight of vehicles will always be one step ahead.
选项
A、the increase in traffic
B、the cost of other materials
C、the change of the climate
D、the construction of the roads
答案
A
解析
“concrete”为“a constraction material consisting of sand,conglomerate gravel,broken stone,or slag in a mortar or cement matrix”混泥土。
转载请注明原文地址:https://tihaiku.com/zcyy/3256564.html
相关试题推荐
What’stheeffectoftheUSslowdown?[br][originaltext]Thekinghastaken
What’stheeffectoftheUSslowdown?[originaltext]Thekinghastakenakno
[originaltext]A:Goodmorning,Mr.Pitt.Dositdown.B:Thankyou.A:Firstof
[originaltext]A:Goodmorning,Mr.Pitt.Dositdown.B:Thankyou.A:Firstof
[originaltext]A:Goodmorning,Mr.Pitt.Dositdown.B:Thankyou.A:Firstof
[originaltext]Host:TheJapaneseprimeminister,JunichiroKoizumi,isprepa
Accordingtothepassage,duringthe18thand19thcenturiescitiesweresmalli
Accordingtothepassage,duringthe18thand19thcenturiescitiesweresmalli
DuringthedraftingoftheDeclarationofIndependenceandthedraftingoftheC
[originaltext]PresidentBushsaysAmericaneedstofocusonresearchanddevelo
随机试题
Forthepastseveralyears,theSundaynewspapersupplementParadehasfeatu
[img]2016m12s/ct_eyyjsdm_eyyjsdreadb_0064_201612[/img]【B1】______Manyofthe
[originaltext]M:Wouldyourathereatathomeorgoouttonight?W:I’drather
Ifyouassociatewithsuchpeople,I’mafraidyou______serioustrouble.A、areh
[originaltext]Inamodernsociety,nocompanycanhopetomakeaprofiton
A.视网膜S抗原、黑色素相关抗原 B.氧自由基代谢产物大量增加 C.细菌、真
在科研试验中,对患者进行试验前应让患者填写()。A.补偿金书 B.知情同意书
关于瑞文测验操作注意事项,下列说法中正确的是()。 A.人数B.可单独重复指导
A.2 B.3 C.0 D.不存在
关于无效合同法律后果的说法,正确的是( )A.无效合同自被确认为无效时起没有法
最新回复
(
0
)