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
51
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 modern 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, around 1912 or 1913.
Mr. Jones: This was because of the increase in traffic?
Engineer: That’s right. 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 sub - grade.
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 example, 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.
Engrneer: 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、Gravel.
B、Asphalt.
C、Macadam.
D、Concrete.
答案
D
解析
The engineer回答是: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.“gravel”为“a loose mixture of rock fragments or pebbles”砾石;“macadam”为“pavement made of layers of compacted broken stone; now usd,bound with tar or asphalt”碎石。
转载请注明原文地址:https://tihaiku.com/zcyy/3256046.html
相关试题推荐
TheAmericancitizenwhowasabductedinPakistan[br][originaltext]AnAme
TheAmericancitizenwhowasabductedinPakistan[originaltext]AnAmerican
Whatisthemainideaofthenewsitem?[originaltext]Theuseofmobileson
WhichofthefollowingisCORRECTabouttheaccident?[br][originaltext]W:Now
WhichofthefollowingisCORRECTabouttheaccident?[originaltext]W:Now,sir,
Microsoft’ssearchengineBing[originaltext]Googleisoneofthesmartest,
WhatistheconsequenceoftheFridaygaspipelineexplosion?[originaltext]
WhichofthefollowingstatementsisCORRECT?[originaltext]Anarsonattack
Whatcanelementaryschoolershavefornutritiousdrinks?[br][originaltext]W:
Whatcanelementaryschoolershavefornutritiousdrinks?[br][originaltext]W:
随机试题
______moresunlight,thesevegetableplantsgrowmuchbetterthisyear.A、Torec
Inthisdecadeoflimitededucational______,thepurchaseofcomputerequipment
CanMixofTeachers,ComputersLeadtoPupilSuccess?[A]Whenvisitorst
Childrencanusuallydress_____bytheageoffive.A、themselvesB、themC、selvesD
面积相等的两个图形分别如图a)和图b)所示。它们对对称轴轴的惯性矩之间的关系为:
女性,28岁,风湿性瓣膜病病史2年。3周前因感冒出现呼吸困难,咳嗽,不能平卧。查
辨别虚实真假的关键是A.脉沉取之有力无力 B.面色的苍老与红润 C.病程的新
2000~2008年,该省年贸易顺差达到最大的年份是:A.2005年 B
2014年6月27日,甲公司与乙公司签订《模具加工合同》,约定:甲公司委托乙公司
对硅沉着病具有诊断意义的病变是A.肺泡炎 B.透明膜 C.出血 D.矽结节
最新回复
(
0
)