水泥实验
1 实验日期
20##年10月21日
2 实验要求
根据国家标准的要求,通过实验并评定新疆天山普通硅酸盐水泥P.O 42.5(强度等级42.5)试样的凝结时间(演示)、安定性和强度等级;并对所实验的水泥试样质量进行综合评定。
3 主要仪器设备
4.1标准稠度用水量、凝结时间和安定性
①GJ-160-2双转双速水泥净浆搅拌机
②标准维卡仪
③量水器(最小刻度0.1ml,精度1%)
④JA12002型电子天平,最大称量不小于1000g,感量0.01g;
⑤湿气养护箱,控制温度为20℃±l℃,相对湿度不低于90%
⑥RAF-A型雷氏法水泥安定性试验用沸煮箱
4.2胶砂强度
①养护箱和养护池
试体带模养护的养护箱或雾室温度保持在(20±1)℃ ,相对湿度不低于90%。
试体养护池水温度应在(20±1)℃范围内。
②JJ-5型水泥胶砂搅拌机
③试模
试模由三个水平的模槽组成,可同时成型三条截面为40mm ×40mm,长160mm的棱形试体。
④NT2000型水泥胶砂试体成型振实台
⑤下料漏斗、试模、搪瓷盘、刮平刀等
⑥抗折、抗压试验机、抗压夹具等
5 实验环境的温、湿度
20##年10月21日,温度:(23±1)°C 湿度:70%
20##年11月18日,温度 (19±1)°C 湿度:61%
6 实验方法及步骤
6.1标准稠度用水量
①实验方法采用标准GB/T 1346-2001《水泥标准稠度用水量、凝结时间、安定性检验方法》中有关“不变水量方法”进行;
②实验步骤
A、试验前应检查仪器金属棒能否自由滑动,调整至试锥接触锥模顶面时指针对准零点,搅拌机运转正常等。
B、水泥净浆的拌制
采用不变水量方法,用量水器量取拌和水量用142.5ml。水量精确至0.5ml。
用水泥净浆搅拌机搅拌,搅拌锅和搅拌叶片先用湿布擦过,将拌和水倒人搅拌锅内,然后在5s~10s内小心将称好的500 g水泥加人水中,防止水和水泥溅出;拌和时,先将锅放在搅拌机的锅座上,然后升至搅拌位置,启动搅拌机,低速搅拌120s,停15s,同时将叶片和锅壁上的水泥浆刮人锅中间,接着高速搅拌120s停机。
注意:若采用调整水量方法时,拌和水量按经验取值。
C、标准稠度用水量的测定
拌和结束后,立即将拌制好的水泥净浆装入锥模中,用小刀插捣,轻轻振动数次,刮去多余的净浆;抹平后迅速放到试锥下面固定的位置上,将试锥降至净浆表面接触,拧紧螺丝1s~2s后,突然放松,让试锥垂直自由地沉入水泥净浆中。到试锥停止沉入或释放试锥30s时记录试锥下沉深度S(mm),升起试锥后,立即擦净。整个操作应在搅拌后1.5 min内完成。
标准稠度用水量P(%)可从维卡仪对应标尺上读取,或根据测得的试锥下沉深度S(mm),按下式计算得到:
P=33.4-0.185S
当试锥下沉深度小于13mm时,应改用调整水量法测定。
6.2凝结时间
①实验方法采用标准GB/T 1346-2001《水泥标准稠度用水量、凝结时间、安定性检验方法》进行;
②实验步骤
A、测定前准备工作:将圆模放在玻璃板上,在内侧涂上一薄层机油;调整凝结时间测定仪,使试针接触玻璃板时,指针对准标尺零点。
B、试件的制备:以标准稠度净浆一次装满试模,振动数次刮平,立即放入湿气养护箱中。记录水泥全部加入水中的时间作为凝结时间的起始时间。
C、初凝时间的测定:试件在湿气养护箱中养护至加水后30 min时进行第一次测定。测定时,从湿气养护箱中取出试模放到试针下,降低试针与水泥净浆表面接触。拧紧螺丝1s~2s后,突然放松,试针垂直自由地沉入水泥净浆。观察试针停止下沉或释放试针30s时指针的读数。当试针沉至距底板4mm±1mm时,为水泥达到初凝状态;由水泥全部加入水中至初凝状态的时间为水泥的初凝时间,用“min”表示。
D、终凝时间的测定:为了准确观测试针沉入的状况,在终凝针上安装了一个环形附件。在完成初凝时间测定后,立即将试模连同浆体以平移的方式从玻璃板取下,翻转180°,直径大端向上,小端向下放在玻璃板上,再放入湿气养护箱中继续养护,临近终凝时间时每隔15 min测定一次,当试针沉入试体0.5mm时,即环形附件开始不能在试体上留下痕迹时,为水泥达到终凝状态,由水泥全部加入水中至终凝状态的时间为水泥的终凝时间,用“min”表示。
测定时应注意,在最初测定的操作时应轻轻扶持金属柱,使其徐徐下降,以防试针撞弯,但结果以自由下落为准;在整个测试过程中试针沉入的位置至少要距试模内壁10 mm。临近初凝时,每隔5 min测定一次,临近终凝时每隔15 min测定一次,到达初凝或终凝时应立即重复测一次,当两次结论相同时才能定为到达初凝或终凝状态。每次测定不能让试针落入原针孔,每次测试完毕须将试针擦净并将试模放回湿气养护箱内,整个测试过程要防止试模受振。
6.3安定性
①实验方法采用标准GB/T 1346-2001《水泥标准稠度用水量、凝结时间、安定性检验方法》中有关“试饼法”进行;
②实验步骤
A、测定前的准备工作
每个样品需准备两块约100 mm×100 mm的玻璃板,凡与水泥净浆接触的玻璃板都要稍稍涂上一层油。
B、试饼的成型方法
将制好的标准稠度净浆取出一部分(约1/4, 150g左右)分成两等份,使之成球形,放在预先准备好的玻璃板上,轻轻振动玻璃板并用湿布擦过的小刀由边缘向中央抹,做成直径70mm~80mm、中心厚约10 mm、边缘渐薄、表面光滑的试饼,接着将试饼放入湿气养护箱内养护24h±2h。
C、沸煮
调整好沸煮箱内的水位,使能保证在整个沸煮过程中都超过试件,不需中途添补试验用水,同时又能保证在30min±5min内升至沸腾。
脱去玻璃板取下试饼,在试饼无缺陷的情况下将试饼放在沸煮箱水中的蓖板上,然后在30min±5min内加热至沸并恒沸180min±5min。
D、结果判别:沸煮结束后,立即放掉沸煮箱中的热水,打开箱盖,待箱体冷却至室温,取出试件进行判别。目测试饼未发现裂缝,用钢直尺检查也没有弯曲(使钢直尺和试饼底部紧靠,以两者间不透光为不弯曲)的试饼为安定性合格,反之为不合格。当两个试饼判别结果有矛盾时,该水泥的安定性为不合格。
6.4胶砂强度
①实验方法采用标准GB/T 17671-1999 《水泥胶砂强度检验方法(ISO法)》进行;
②实验步骤
A、将试模擦净,接触面上涂黄油,紧密装配,防漏浆
B、水泥与标准砂的质量比为1:3,水灰比为0.5。每成型3条试件需要称量水泥450g、标准砂1350g、水225ml
C、搅拌时先将水加入锅具,再加入水泥,固定锅具,开机搅拌,低速搅拌30s后,在第二个30s开始的同时均匀的将砂子加入。把机器转至高速再拌和30s。停拌90s,在第一个15s内用一胶皮刮具将叶和锅壁上的胶砂刮入锅中间,再高速搅拌60s。注意各阶段时间误差应在1s内。
D、固定试模和模具于振动台上,将搅拌锅里胶砂分两层装入试模,装第一层时,每个槽里约放300g胶砂,用大播料器垂直架在模套顶部沿每个模槽来回一次将料层播平,接着振实60次。再装人第二层胶砂,用小播料器播平,再振实60次。
E、移走模套,从振实台上取下试模,放在平台上,用一金属直尺接近垂直的角度架在试模模顶的一端,然后沿试模长度方向以横向锯割动作慢慢向另一端移动,一次将超过试模部分的胶砂刮去,并用同一直尺以近乎水平的情况下将试体表面抹平。
F、将试件编号、养护。
G、到试验龄期时进行抗折、抗压强度试验
每龄期取出3个试件,先做抗折强度实验,实验前须擦去试件表面水分和砂粒,清除夹具上圆柱表面粘着的杂物,试件放入抗折夹具内,应使试件侧面与圆柱接触。
调节抗折试验机的零点与平衡,开动电机以50 N/S±10N/S速度加荷,直至试件折断,记录破坏荷载Ff(N)。
抗折试验后的6个断块,应立即进行抗压试验,抗压强度测定须用抗压夹具进行,试体受压断面为40mm×40mm,试验前应清除试体受压面与加压板间的砂粒或杂物;试验时,以试体的侧面作为受压面,并使夹具对准压力机压板中心。
开动试验机,控制压力机加荷速度为2400N/S±200N/S,均匀地加荷至破坏。记录破坏荷载Fc(N)。
7 实验记录
1.标准稠度用水量:P=33.4-0.185S
计算结果为: 28.9%
2.凝结时间:
初凝时间:109min
终凝时间:286min
3.安定性:
目测试饼没有发现裂缝,用钢直尺检查也没有发现弯曲
4.胶砂强度:
①三天时的抗折强度:
②三天时的抗压强度:
③28天时的抗折强度:
④28天的抗压强度:
8 结果计算与分析讨论
①水泥的凝结时间、安定性按相关标准进行计算和分析,并对照标准GB 175-2007《通用硅酸盐水泥》的相应要求进行评定;
②水泥的强度等级,按标准GB 17671-1999 《水泥胶砂强度检验方法(ISO法))》进行计算和数据处理,将试验及计算所得到的各龄期抗折和抗压强度值,对照标准所规定的水泥各龄期的强度值,来确定水泥强度等级。要求各龄期的强度值均不低于标准所规定的强度值。
③结论
对所实验的水泥试样质量进行综合评定。
9 结论
通过与标准GB 175-2007《通用硅酸盐水泥》的相应要求进行评定,
初凝时间≥45min 终凝时间≤10h,符合要求
安定性:目测试饼没有发现裂缝,用钢直尺检查也没有发现弯曲,说明该水泥的安定性合格
第二篇:The book report of love of life2杰克伦敦《热爱生命》英文读书报告
The book report of love of life
By Jack London
The famous novel "love life" was a sensation in Europe and America. It indicates the nature of the strong, brave and adventurous spirit of human beings. This novel, by Jack London showing how to love life to help overcome the death of a person. Despite being hungry, being sick, being exhausted, the hero in the story was still in the struggle to fight against Dealth, and a dying wolf . At last, he was finally rescued by the people of a ship.
The tragic story, vividly demonstrates the persistence of a human being. Full display of the depths of human nature , and vivid descriptions of a life's potential and strong. The spirits are precious.
That day he decreased the distance between him and the ship by three miles; the next day by two-for he was crawling now as Bill had crawled; and the end of the day found the ship still seven mailes away and him unable to make even a mile a day. Still the indian summer held on, and he continued to crawl and faint ,turn and turn about; and ever the sick wolf coughed and wheezed at his heels. His knees had become raw meat like his feet, and though he paddled them with the shirt from his back it was a red track he left behind him on the moss and stones. Once , glancing back, he saw the wolf licking hungrily his bleeding trail, and he saw sharply
what his own end might be-unless-unless he could get the wolf. Then began as grim a tragedy of existence as was ever played-a sick man that crawled, a sick wolf that limped, two creatures dragging their dying carcasses across the desolation and hunting each other’s lives.
The ship was more than four miles away. He could see it quite distinctly when he rubbed the mists out of his eyes. But he could never crawl those four miles. He knew that, and was very calm in the knowledge. He knew that he could not crawl half a mile. And yet he wanted to live. It was unreasonable that he should die after all he had undergone. Fate asked too much of him. He declined to die. It was stark madness, perhaps, but in the very grip of Death he defied Death and refused to die.
Life itself contains enormous potential energy. Sometimes life is very fragile; life, but sometimes unusual strong, so strong was amazing which allows you to confront no matter what happened.
On the one hand, as long as the hearts of survival is also the belief that they do not easily give up their lives, On the other hand, love life, it is necessary to have faith, be pursued.
Jack London's "love life" has given us a profound lesson: In order to achieve a life goal, it is necessary to life with all difficulties and obstacles on the road to do the life-and-death struggle, and daring to win. In the face of life and work of the difficulties and even life-threatening, we can not wait for the failure still, apart from the victory because we have no
choice! This novel's main character in the face of many difficulties and obstacles, wants to give up life. But he did not die willingly, he chose to fight. As a result, life must be pursued. It is necessary to live a very dynamic game, career achievements. We must learn to live in strong and learn to fight so that we can live up to the life of the great trust in order to be worthy of life itself. Never, never, never give up!