问题 问答题

案例三

【背景】

某办公楼建筑面积4500 m2,主体结构为现浇钢筋混凝土框架结构,混凝土为商品混凝土,组合钢木模板,柱混凝土强度等级为C30。在主体结构施工过程中,第三层柱因模板拼缝不严,造成有多处的孔洞、蜂窝和麻面。经现场混凝土强度检测,混凝土强度满足设计要求,但修补造成经济损失1.2万元。

【问题】

(1)试述混凝土孔洞处理的步骤。

(2)防治混凝土蜂窝,麻面的主要措施有哪些

(3)本次工程质量事故属于哪一类,依据是什么

答案

参考答案:

(1)对孔洞处理的主要步骤。

①将孔洞内松动险、浮浆及杂物等清除干净;

②用清水冲洗、润湿孔洞,必要时支模;

③用高一个强度等级微膨胀细石险填实孔洞;

④养护。

(2)主要防治措施:

①确保混凝土的配合比和搅拌质量等符合要求;

②模板接缝要严密,且表面要光滑、平整;均匀涂刷隔离剂(或脱模剂);

③模板及支架要牢固(或要有足够的强度、刚度和稳定性);

④混凝土浇筑工序正确且振捣要密实;

⑤合理养护,并控制好拆摸时间。

(3)本次事故为一般事故(或答“一般施工质量事故”)。一般事故指经济损失一次在1万元(或 5000元)以上,10万元以下,或人员重伤2人以下且无死亡人员的事故。

填空题

(13分)A、B、C、D、E是元素周期表中前四周期常见元素,其原子序数依次增大。已知:

A单质在自然界中硬度最大
B原子中s能级与p能级电子数相等且有单电子
CC同在B的下一周期,C的电离能数据(kJ ·mol-1)为:I1=738  I2=1451  I3=7732  I4=10540
D单质密度小,较好的延展性,广泛用于食品包装,D的氧化物是两性氧化物
E单质是一种常见金属,与O元素能形成黑色和砖红色两种氧化物
(1)写出A元素基态原子的价电子排布图                 。当C单质、D单质和NaOH溶液形成原电池时,该原电池的负极的电极反应式为:                         

(2)常温下,某气态单质甲分子与AB分子核外电子数相等,则一个甲分子中包含     个π键,在A—H、B—H两种共价键中,键的极性较强的是           (用元素符号表示)。D元素原子核内中子数比质子数多1,则D原子可以表示为            ,其原子核外有        种运动状态不同的电子。

(3)B的氢化物的熔沸点比与它同主族的下一周期元素的氢化物的熔沸点高,原因是

                                                      

(4)通常情况下,A的燃烧热为a kJ ·mol-1,C的燃烧热为b kJ ·mol-1,则C与AO2反应生成A的热化学方程式为                                                

阅读理解

阅读理解。

阅读下面的短文,并根据文章后的题目要求回答1-5小题。

     (1)While adults need to eat breakfast each day to perform their best, kids need it even more. Their

growing bodies and developing brain rely heavily on the regular intake of food. When kids skip breakfast,

they can end up going for as long as eighteen hours without food. This period of semi-starvation can create

a lot of physical, intellectual, and behavioral problems for them.

     (2)If you and your kids regularly skip breakfast to save time or to get a few more minutes of sleep,

remember that eating a healthy morning meal will probably save your time in the long run. By recharging

your brain and your body, you'll be more efficient in just about everything you do.

     (3)Interestingly, studies show that kids who skip breakfast are late for and absent from school more

often than children who eat breakfast on a regular basis. Time invested in breakfast is much more valuable

than the few extra minutes of sleep you might get by skipping the morning meal. If you and your kids seem

unable to make time for breakfast, consider enrolling your children in a school breakfast program. If possible,

pack a breakfast brown-bag the night before so that you and your kids can eat on the way to school and

work.

     (4)Some people skip breakfast in an effort to lose weight, but actually it is more likely to cause weight

gain rather than weight loss. Skipping breakfast is strongly linked to the development of obesity. According

to research, skipping meals, especially breakfast, can actually make weight control ________. Breakfast

skippers tend to eat more food than usual at the next meal or eat high-calorie snacks to get rid of hunger.

      (5)To teens, especially teenage girls, skipping breakfast may seem like a perfect way to lose weight.

It's important for moms to educate their kids about the importance of the morning meal and role it plays

in maintaining good health and preventing obesity.

1. What is mainly discussed in the passage? (no more than 6 words)

________________________________________________________________________________________

2. Complete the following statement with proper words. (no more than 3 words)

Sparing some time__________ is more beneficial to you than skipping it for more sleep.

3. List three reasons why many kids and adults skip breakfast. (no more than 10 words)

_________________________________________________________________________________________

4.Fill in the blank in Paragraph 4 with proper words. (no more than 4 words)

________________________________________________________________________________________

5. What does the underlined word"it" in the last paragraph probably refer to? (no more than 3 words)

________________________________________________________________________________________