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
40
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、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/3256563.html
相关试题推荐
[originaltext]W:GoodeveningandwelcometoBusinessPeople.Wearefortunate
[originaltext]W:GoodeveningandwelcometoBusinessPeople.Wearefortunate
[originaltext]W:GoodeveningandwelcometoBusinessPeople.Wearefortunate
WhichofthefollowingstatementsisCORRECT?[br][originaltext]W:Fromachil
WhichofthefollowingstatementsisCORRECT?[br][originaltext]W:Fromachil
WhichofthefollowingstatementsisCORRECT?[originaltext]W:Fromachildhood
Itis______whodirectmanyCosaNostra’sactivitiesinPalermo.[originaltext]
[originaltext]ALLEN:SomescientistsofUFOsareissuingareportthatmayheat
[originaltext]ALLEN:SomescientistsofUFOsareissuingareportthatmayheat
[originaltext]TheU.S.DefenseDepartmenthasalwaysbeenproudofitspowe
随机试题
Tostudypredators,onemustadopttheroleof______thatis,refrainfrominterf
InwhichdomainwillGoogleandSuncooperatetochallengeMicrosoft?[br][or
DearManager,Afteraseriousconsideration,Ihavedefinitelydecidedtores
婴儿的依恋类型可以分为()A.安全依恋型 B.回避的非安全依恋型 C
患者牙痛剧烈,伴口臭,口渴。便秘,舌苔黄,脉洪。治疗应首选A.外关 B.地仓
甲房地产经纪公司(以下简称甲公司)所处城市近年来经济发展迅速,外来务工人员和个体
关于房地产经纪人在代理合同中的义务的说法,错误的是()。A:应按照被代理人的指
甲公司因企业改制分立成乙公司和丙公司。乙公司对登记在丙公司名下1栋房产的归属提
根据增值税法律制度的规定,销售商标使用权按照()征收增值税。A.销售无形资产
(2018年真题)企业年末将损益类科目结转后,“本年利润”科目的借方余额表示实现
最新回复
(
0
)