问题 问答题 简答题

什么是混凝土的和易性?它包括有几方面涵义?

答案

参考答案:

和易性是指混凝土拌合物能保持其组成成分均匀,不发生分层离析、泌水等现象,适于运输、浇筑、捣实成型等施工作业,并能获得质量均匀、密实的混凝土的性能。

和易性包括流动性、粘聚性和保水性三方面的涵义:

1、流动性是指混凝土拌合物在自重或机械振捣力的作用下,能产生流动并均匀密实地充满模型的性能。

2、粘聚性是指混凝土拌合物内部组分间具有一定的粘聚力,在运输和浇筑过程中不致发生离析分层现象,而使混凝土能保持整体均匀的性能。

3、保水性是指混凝土拌合物具有一定的保持内部水分的能力,在施工过程中不致产生严重的泌水现象的性能。

探究题
阅读理解

It was a Sunday and the heavy storm had lasted all night. The morning after the storm, though, was beautiful: blue skies, warm air and a calm, inviting sea touching the shore gently.

My father realized it was a good day for fishing and invited my sister and me to go with him. I was only 14 and fishing had never been my thing, but I decided to go all the same. I’m so glad I did.

On the road to the harbour we could see the terrible destruction on the coast, but the harbour itself was in fairly good shape. After all, it was protected by the arms of a bay that had only one tiny channel to the sea. As we got on board, we noticed two big humps(脊背) in the distance.

On approaching them, we saw it was a mother whale with her baby. We couldn’t believe it ——there aren’t any whales along the coast here. The storm must have driven them across the ocean into the bay, in which the still water was so badly polluted that nothing could survive.

The little baby whale——actually as big as our boat——was obviously stuck and could not move. The mother dived under the water and came up suddenly, making big whirlpools(漩涡) and waves. ”She’s trying to help her baby, but on the wrong side, ”my father said. At this point, my father moved our boat in a semicircle to the other side and, heading the boat towards the baby whale, pushed it gently. With our several gentle pushes the big hump turned over and disappeared under water. Then it swam up right beside its mum. They struggled in their desperate attempts to escape but missed the exit and started heading in the wrong direction. We hurried up to the whales and tried to lead them towards the bay channel. Slowly, they let us lead them, some-times rising from the water right beside us to breathe——and to give us a trusting look with those huge eyes. Once they hit their first part of clean water flowing straight from the sea, the mum gave us a wave with her tail and off they swam into the distance.

In the excitement it had felt like only a few minutes, but we had been with those wonderful animals for almost an hour and a half. That was the simple and lasting beauty of the day, Nearly four decades later, I still look back fondly to that golden day at sea.     

小题1:The author says “I’m so glad I did ” (in Para. 2)because ______.

A.he witnessed the whole process of fishing

B.he enjoyed the beauty of the calm sea

C.he experienced the rescue of the whales

D.he spent the weekend with his family小题2:The harbour survived the storm owing to____________.

A.the shape of the harbour

B.the arms of the bay

C.the still water in the channel

D.the long coast line小题3:The mother whale failed to help her baby because__________.

A.she had stayed in the polluted water for too long

B.the whirlpools she had made were not big enough

C.she had no other whales around to turn to for help

D.the waves pushed her baby in the wrong direction小题4:what is the theme of the story?

A.Saving lives brings people a sense of happiness

B.Fishing provides excitement for children

C.It’s necessary to live in harmony with animals

D.It’s vital to protect the environment