Another thing to remember in connection with concrete is that you are not allowed very much freedom for errors in either measurements or location. Once you have a solid mass of concrete set in place, it is going to stay there. You have a difficult job ahead of you if you try to remedy a mistake. Make very sure, before you fill the form, that everything is where and how you want it.
There are numerous rules regarding the proper mixing, handling, and finishing of concrete, but the essential one concerns the amount of water to use. The less water in the mix, the less the finished job will shrink. The less water used, the harder and more enduring the job after it has set.
The amateur concrete worker is annoyed with two desires. One is to use enough water to have the concrete nice and soft and easy to push around. You have been warned against that. The second is to take off the wooden forms too early, to see what the job looks like. That is really fatal. If the forms are stripped off too soon, while the concrete is still green, two things are likely to happen you are almost sure to break off corners or edges, and you are likely to cause a major crack or defect in the body of the work. An excellent rule is to wait until you are sure the concrete is properly hardened, and then wait another day before removing the forms.
Questions:
1. What would be the title for the selection?
______________ ______________ _______________ ______________ _____________
______________ ______________ _______________ ______________ _____________
2. What does the essential rule concern?
______________ ______________ _______________ ______________ _____________
______________ ______________ _______________ ______________ _____________
3. What is one of the desires the amateur must resist?
______________ ______________ _______________ ______________ _____________
______________ ______________ _______________ ______________ _____________
4. Which of the following qualities is not essential in someone who works with concrete: carefulness, diligence, patience, or self-control?
______________ ______________ _______________ ______________ _____________
______________ ______________ _______________ ______________ _____________
5. What does the author mean by saying the concrete is green?
______________ ______________ _______________ ______________ _____________
______________ ______________ _______________ ______________ _____________
Unit 4
S1. Rules for Working with Concrete.
S2. The amount of water to use.
S3. To use too much water. / To take off the wooden from too early.
S4. Diligence.
S5. Not dried out. / Not dry enough.
初中英语主动语态知识点详解:主动形式表被动含义
初中英语被动语态知识点详解:“get+过去分词”表被动的用法
初中英语will / shall”与“be going to”两者的区别
初中英语一般过去时知识点详解
初中英语固定短语知识点详解:初中61个常用短语总结
初中英语被动语态知识点详解:一般不用于被动语态的静态动词
初中英语时态知识点:一般过去时三种变化技巧
初中英语主动语态知识点详解:主动形式表示被动意义
初中英语固定短语知识点详解:固定短语句型的作用与解释
初中英语时态知识点:一般将来时表时间
初中英语语法大全:不用被动语态
初中英语被动语态知识点详解:常用时态的被动语态
初中英语主动语态知识点详解
初中英语时态知识点详解:一般过去时表现在
初中英语因定短语知识点详解:重点短语句型详解
初中英语时态知识点:过去进行时与一般过去时的区别
初中英语时态知识点:初中英语一般过去时的应用
初中英语被动语态知识点详解:两类被动句型的转换
初中英语被动语态知识点详解:不用于被动语态的情形
初中英语被动语态知识点详解:使用被动语态“六注意”
初中英语被动语态知识点详解:表示“据说”的三类被动句型
初中英语时态知识点:一般疑问形式
初中英语时态知识点:一般将来时肯定形式
初中英语短语知识点详解:动词+介词的固定短语
初中英语时间知识点:一般过去时的构成及用法说明
初中英语短语知识点详解:动词+副词短语分类及用法
初中英语固定短语知识点详解
初中英语时态知识点:一般将来时结构形式
初中语法精挑细讲之动词的语态
初中英语时态知识点:一般过去时代替完成时
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |