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
2024-12-03
24
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/3871124.html
相关试题推荐
ThefirstChinesetoreachtheUnitedStatescameduringtheCaliforniaGold
WhichofthefollowingisNOTtrueaccordingtothenews?[originaltext]OnF
[originaltext]LiHua:Pardonme.I’mtryingtofindarticlesonecology.Canyo
[originaltext]LiHua:Pardonme.I’mtryingtofindarticlesonecology.Canyo
[originaltext]LiHua:Pardonme.I’mtryingtofindarticlesonecology.Canyo
[originaltext]WorldTradeOrganizationchiefSupachaiPanitchpakdisaysall
[originaltext]WorldTradeOrganizationchiefSupachaiPanitchpakdisaysall
Whatisthemainideaofthenewsitem?[br][originaltext]Thebattleagain
Whatisthemainideaofthenewsitem?[originaltext]Thebattleagainstmal
WhydidMr.Greenhaveaterriblefuelbilllastwinter?[originaltext]Mr.Green
随机试题
Thereasonthatwaterproblemwillbecomemoreandmoreseriousis______.[br]
IsHeadphoneGoodforWork?A)MarissaYuworksinabusyoff
Drought,tsunami,violentcrime,financialmeltdown—theworldisfullofris
Amajorsociologicaltheoryknownassymbolicinteractionismofferssomeimp
中国书法(Chinesecalligraphy)是一门古老的汉字书写艺术,它是中国最高的艺术形式。书法是在洁白的纸上,靠毛笔(brush)的运动留下水
【教学过程】 (一)热身活动:数学成绩出来后 1.播放短片 数学成绩出来了。 王俊:我就知道是这样,我压根儿没有数学基因,我弟弟数学也不好,放弃
下列关于俄国十月革命对中国影响的表述,正确的是 A.新文化运动兴起 B.孙中
下列关于概化理论的表述,错误的是A.属于随机抽样理论 B.关于行为测量可靠性的
(一)甲利用出境之便,为患者从境外代购少量药品,适当加价后售予他人,从中赚取差价
李某是某汽车零件生产公司的总经理,得益于近十年来中国汽车工业的高速发民和良好的经
最新回复
(
0
)