水泥类(一)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î一、填空题'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î1.水泥新标准规定用沸煮法检验水泥的安定性可以采用两种试验方法,标准法是指雷氏夹法,该法是测定水泥净浆在 沸煮箱 中沸煮后的 值来检验水泥的体积安定性的。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î2.水泥封存样应封存保管时间为'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
三个月'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î3.水泥标准稠度用水量试验中,所用标准维卡仪,滑动部分的总质量为300g±1g.'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î4.水泥标准稠度用水量试验,试验室温度为20℃±2℃,相对温度不低于50%,湿气养护箱的温度为20±1℃,相对湿度不低于90%。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î5.水泥封存样应封存保管三个月,在存放样品的容器应至少在一处加盖清晰,不易擦掉的标有编号,取样时间\地点\人员的密封印.'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î6.GB175—1999中对硅酸盐水泥提出纯技术要求有 细度 、 凝结时间 、 体积安定性'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î7.硅酸盐水泥的强度等级时根据 水泥胶砂强度 试验测得的'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
3'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
天和 '¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
28'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
天强度确定的。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î8.水泥胶砂搅拌机的搅拌叶片与搅拌锅的最小间隙'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
3'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
mm,应 一 月检查一次。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î9.《水泥胶砂强度检验方法(ISO)法(GB/T17671-1999)适用于 硅酸盐 水泥、 普通硅酸盐 水泥、 矿渣硅酸盐 水泥、 粉煤灰硅酸盐 水泥、 复合 硅酸盐 水泥、 石灰石硅酸盐 水泥的抗压与抗折强度试验。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î10.水泥胶砂试件成型环境温度应为'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
20 ±2℃ ,相对湿度应为'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
50% 。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î11.水泥细度试验中,如果负压筛法与水筛法测定结果发生争议时,以 负压筛 法为准。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î12.在水泥混凝土配合比设计进行试拌时,发现坍落度不能满足要求,此时,应在保持( 水灰比 )不变的条件下,调整(水泥浆用量 ),直到符合要求为止。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î13.水泥混凝土的工作性是指水泥混凝土具有流动性、可塑性、稳定性和易密性等几方面的一项综合性能。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î14.影响混凝土强度的主要因素有(材料组成).(养护湿度和温度)和(龄期 ),其中(材料组成)是.影响混凝土强度的决定性因素。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î15.设计混凝土配合比应同时满足(经济性).(结构物设计强度).(施工工作性 )和(环境耐久性)等四项基本要求。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î16.在混凝土配合比设计中,水灰比主要由( 水泥混凝土设计强度 )和(水泥实际强度)等因素确定,用水量是由(最大粒径和设计坍落度)确定,砂率是由(最大粒径和水灰比)确定。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î17.抗渗性是混凝土耐久性指标之一,S6表示混凝土能抵抗( 0.7'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)Mpa的水压力而不渗漏。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î18.水泥混凝土标准养护条件温度为 20±2℃ ,相对湿度为95% 。或温度为'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
20±2℃ 的不流动的 Ca(OH)2'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
饱和溶液养护。试件间隔为'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
10-20mm'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î19、砼和易性是一项综合性能 ,它包括 流动性 , 粘聚性 , 保水性 ,等三方面含义。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î20、测定砼拌合物的流动性的方法有 坍落度法 和 维勃绸度法 。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î21、确定混凝土配合比的三个基本参数是: W/C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
、 砂率 、 用水量W'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î22.影响水泥混凝土强度的主要因素有( 材料组成 )、(养护温度 )、(养护湿度 )和(龄期 )。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î23、水泥混凝土抗折强度是以'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
150'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
mm×'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
150'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
mm×'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
550'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
mm的梁形试件在标准养护条件下达到规定龄期后,采用 点 双支点三分 处加荷方式进行弯拉破坏试验,并按规定的计算方法得到的强度值。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î24.GB/T50081-2002《普通混凝土力学性能试验方法》标准中规定:压力试验机测量精度为 ±1% ,试件破坏荷载必须大于压力机全量程的20%,但小于压力机全程的'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
80% ,压力机应具有 加荷速度指标 装置或 加荷速度控制 装置'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î25.水泥的技术性质?'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:水泥技术性质:物理性质(细度、标准稠度、凝结时间、安定性)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î 力学性质(强度、强度等级)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î 化学性质(有害成分、不溶物、烧失量)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î29.水泥细度试验几种方法的比较'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:(1)负压筛法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (2)水筛法:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (3)水泥比表面积法:它是以单位质量水泥材料表面积的大小来表示细度;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î30.水泥净浆标稠的试验步骤'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:准备工作:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(1)试验前必须做到维卡仪的金属棒能自由滑动,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(2)调整至试杆接触玻璃板时指针对准零点,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(3)搅拌机运行正常'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(4)净浆搅拌机的搅拌锅和搅拌叶片先用湿布擦过。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î试验过程:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(1)称取试样500g;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(2)根据经验用量筒量取一定的用水量,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
注:用同一只量筒'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(3)将拌和水倒入搅拌锅内,然后再5S-10S内小心将称好的水泥加入水中 注:小心有飞扬物飘出'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(4)安置好搅拌机,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入锅中间,接着高速搅拌120S停机。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î测定步骤:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(1)将拌制好的水泥净浆装入以置于玻璃板上试模中,用小刀插捣,轻轻振动数次,刮去多余的净浆。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(2)抹平后迅速将试模和底板移到维卡仪上,并将其中心定在试杆下,降低试杆直至与水泥竟将表面接触,拧紧螺丝1S-2S后,突然放松,使试杆垂直自由地沉入水泥净浆中。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(3)在试杆停止沉入或释放试杆30S时记录试杆到 底板的距离,升起试杆后,立即擦净;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(4)整个操作应在搅拌后1.5min内完成,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(5)以试杆沉入净浆距底板6±1mm的水泥净浆为标准稠度净浆;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(6)拌合水量为水泥的标准稠度用水量(P)按水泥质量的百分比计;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(7)重新调整用水量,若距底板大于要求,则要增加用水量;若距底板小于要求,则要减少用水量。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î31.水泥凝结时间的试验步骤'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(一)初凝时间的测定:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(1)当试件在湿气养护箱中养护至加水后30min时进行第一次测定。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(2)从湿气养护箱中取出试模放到试针下,降低试针与水泥竟将表面接触。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(3)拧紧螺丝1S-2S后,突然放松,试针垂直自由地沉入水泥净浆,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(4)观察试针停止沉入或释放试针30S时指针的读数;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(5)达到初凝时应立即重复测一次,当两次结论相同时才能定为达到初凝状态。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(二)终凝时间的测定:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(1)取下试针换上终凝针;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(2)将试模连同浆体以平移的方式从玻璃板取下,翻转180度,直径大端向上,小端向下放在玻璃板上;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(3)放入湿气养护箱中继续养护,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(4)在最后临近终凝时间的时候每隔15分钟测定一次。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(5)当试针沉入试体0.5mm时,环形附件开始不能在试体上留下痕迹时,为终凝状态,时间阶段为终凝时间;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(6)达到终凝状态应立即重复测一次,当两次结论相同时才能定为达到终凝状态。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î32.水泥的安定性是由什么引起的'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:水泥的安定性不良是由于水泥中某些有害成分造成的,如三氧化硫、水泥煅烧时残存的游离氧化镁或游离氧化钙。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î目前采用的安定性检测方法只是针对游离氧化钙的影响。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î33.进行水泥安定性检验的试验方法?'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î 答:测定水泥体积安定性是雷氏夹法(标准法)和试饼法(代用法)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î34.安定性试验的沸煮法主要是检测水泥中是否含有过量的三氧化硫。(F)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î35.水泥胶砂强度的结果如何处理'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:组三个试件得到的六个抗压强度算术平均值为试验结果。如六个测定值中有一个超出六个平均值的±10%,舍去该结果,而以剩下五个的平均数为结果,如五个测定值中再有超过五个结果的平均数±10%,则该次试验结果作废。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î36.水泥混凝土的配合比设计步骤'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:(1)计算初步配合比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (2)提出基准配合比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (3)确定试验室配合比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (4)换算工地配合比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î37.混凝土配合比的表示方法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:水泥混凝土配合比表示方法:单位用量表示法和相对用量表示法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î38.普通水泥混凝土组成材料中水泥品种及其适用性;P256'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î39.水泥混凝土的技术性质'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:水泥混凝土的技术性质包括新拌和时的工作性和硬化后的力学性质'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î40.工作性就是流动性(F)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î 解释:因为水泥混凝土的工作性包括流动性、可塑性、稳定性和易密性等几个方面的一项综合性能。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î41.工作性的检测方法,以及其使用范围'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:(1)坍落度法:适用于集料粒径不大于31.5(40)mm,坍落度值不小于10mm的混凝土拌和物'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (2)维勃稠度试验:适用于集料粒径不大于40mm,坍落度值小于10mm的塑性混凝土'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î 适用于集料公称最大粒径不大于31.5mm,以及维勃时间在5S-30S之间的干稠性水泥混凝土'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î42.混凝土拌合物的坍落度试验步骤'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:1、试验前将坍落筒内外洗净,放在经水润湿过的钢板上,踏紧踏脚板。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î2、将代表样分三层装入筒内,每层装入高度稍大于筒高约1/3,用捣棒在每一层的横截面上均匀插捣25次,插捣在全部面积上进行,沿螺旋线由边缘至中心,插捣底层时插至底部,插捣其他两层时,应插透本层并插入下层约20~30mm,插捣须垂直压下(边缘部分除外),不得冲击。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î3、在插捣顶层时,装入的混凝土应高出坍落筒,随插捣过程随时添加拌和物,当顶层插捣完毕后,将捣棒用锯和滚的动作,以清除掉多余的混凝土,用馒刀抹平筒口,刮净筒底周围的拌和物,而后立即垂直地提起坍落筒,提筒在5~10s内完成,并使混凝土不受横向及扭力作用,从开始装筒至提起坍落筒的全过程,不应超过2.5min。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î4、将坍落筒放在锥体混凝土试样一旁,筒顶平放木尺,用小钢尺量出木尺底面至试样坍落后的最高点之间的垂直距离,即为该混凝土拌和物的坍落度。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î5、同一次拌和的混凝土拌和物,必要时,宜测坍落度两次,取其平均值作为测定值。每次需换一次新的拌和物,如两次结果相差20mm以上,须作第三次试验,如第三次结果与前两次结果均相差20mm以上时,则整个试验重作。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î6、测定坍落度的同时,可用目测方法评定混凝土拌和物的下列性质,并记录。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î棍度:按插捣混凝土拌和物时难易程度评定,分“上”、“中”、“下”三级。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“上”:表示插捣容易;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“中”:表示插捣时稍有石子阻滞的感觉;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“下”:表示很难插捣。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î含砂情况:按拌和物外观含砂多少而评定,分“多”、“中”、“少”三级。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“多”:表示用馒刀抹拌和物表面时,一两次即可使拌和物表面平整无蜂窝;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“中”:表示抹五、六次才可使表面平整无蜂窝;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“少”:表示抹面困难,不易抹平,有空隙及石子外露等现象。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î粘聚性:观测拌和物各组成分相互粘聚情况,评定方法用捣棒在已坍落的混凝土锥体一侧轻打,如锥体在轻打后渐渐下沉,表示粘聚性良好,如锥体突然倒坍,部分崩裂或发生石子离析现象,即表示粘聚性不好。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î保水性:指水分从拌和物中析出情况,分“多量”、“少量”、“无”三级评定。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“多量”:表示提起坍落度筒后,有较多水分从底部析出;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“少量”:表示提起坍落度筒后,有少量水分从底部析出;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î“无”:表示提起坍落度筒后,没有水分从底部析出。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î四、结果计算及注意事项'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îa)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
混凝土拌和物坍落度以mm计,结果精确至5mm。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î在测定新拌混凝土工作性时,实测坍落度,若与要求坍落度不符,要求调整材料组成,重新拌和,重新测定,直至符合要求为止,提出基准配合比。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î43.影响混凝土工作性的因素'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:(1)原材料特性(2)单位用水量(3)水灰比(4)砂率 '¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î44.影响混凝土抗压强度的主要因素'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:(1)水泥强度和水灰比;(2)集料特性(3)浆集比;(4)养护条件;(5)试验条件'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î45.降低水灰比是否影响其流动性'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答;降低水灰比,会影响到水泥混凝土的流动性变小。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î46.降低水灰比是否影响其强度'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:降低水灰比会降低混凝土强度 '¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î47.混凝土配合比中确定砂、石的用量时所具备条件 '¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î48.混凝土离析的原因'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:(1)砂率过小,砂浆数量不足会使混凝土拌和物的粘聚性和保水性降低,产生离析和流浆现象;'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î (2)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î '¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î49.水泥混凝土的耐久性:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î答:水泥混凝土的耐久性包括:抗冻性、混凝土的耐磨性、碱-骨料反应、混凝土的碳化、混凝土的抗侵蚀性'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î50.水泥混凝土的凝结时间是通过测定贯入阻力的试验方法,检测混凝土拌和物的凝结时间的'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î51.150×150×550mm的小梁试件,以三分点双荷载方式,按0.5-0.7mpa的加载速度( )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î53.一组三根标准水泥混凝土抗折试件进行抗折试验,其极限破坏和在分别是36.55、37.55、43..33,则最后的试验结果是( )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î53.混凝土的最佳砂率是指在水泥浆用量一定的条件下,能够使新拌混凝土的流动性最大的砂率( )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î二、判断题'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î1.水泥试验初凝时间不符合标准要求,此水泥可在不重要的桥梁构件中使用。(×)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î2.沸煮法主要检测水泥中是否含有过量的游离CaO, 游离MgO和三氧化硫。( × )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î3.评价水泥质量时,凡氧化镁,三氧化硫,凝结时间的任一项不符合国家标准规定时,则该水泥为废品。(×)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î4.水泥包装标志中水泥品种、强度等级、生产者名称和出厂编号不全的属于不合格品。( √ )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î5.水泥标准稠度用水量试验中,所用标准维卡仪,滑动部分的总质量为300g±1g。(√)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î6.用沸煮法可以全面检验硅酸盐水泥的体积安定性是否良好。(×)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î7.采用比表面积方法比筛析法能够更好的反映水泥颗粒的粗细程度(T)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î8.水泥胶砂强度 试件应在脱模前 进行 编号。对于二个龄期 以上的试件,在编号时应将同一试模中的三条试件放在一个龄期内。 (×)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î9.与水拌和后成为塑性胶体,既能在空气中硬化,又能在水中硬化,水泥是一种水硬性胶凝材料。√'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î10.我国水泥胶砂强度检验方法从GB177-85过渡到GB/T17671-1999(即ISO法),原水泥标号525相当于ISO强度等级42.5。√'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î11.GB/T1767-1999水泥胶砂强度方法(ISO法不适用于粉煤灰水泥。(×)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î12、用粒化高炉矿渣加入少量石膏共同磨细,即可制得矿渣硅酸盐水泥。( )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î13.对混凝土拌合物坍落度大于220mm应采用坍落度扩展法测定稠度。(√)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î14.采用标准养护的混凝土试件在拆模后 可放在温度 为20±2℃的不流动 的水中进行养护。×'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î15.新拌混凝土的工作性主要从流动性、可塑性、稳定性和易密性四个方面 来 判断其 综合性能。(√)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î16.烧失量试验主要是测定各类土中 有机质成分及测定水泥、石灰 、粉煤灰 中含碳物质燃烧的完全程度。( )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î17.混凝土粗集料最大粒径不得超过结构尺寸的四分之一。( )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î18.混凝土中掺入减水剂,如果保持工作性和强度不变的条件下,可节约水泥的用量。( × )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î19.对混凝土拌合物流动性大小起决定作用的是加水量的大小 。( × )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î20.水泥混凝土流动性大说明其和易性好。( × )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î21、普通混凝土的强度与其水灰比成线性关系。×'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
22、计算混凝土的水灰比时,要考虑使用水泥的实际强度。( √)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
23、砂浆的流动性是用分层度表示的。( √ )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î24.水泥混凝与抗压强度、轴心抗压强度和劈裂抗拉强度结果强度值的确定方法一样。(F )'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î25.钢筋混凝土桥梁构件裂缝宽度在正常使用阶段应小于0.2mm.'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
( T)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î26.混凝土的抗压强度以三个试件的平均值为测量值,如任一个测值与中值差超出中值15%时,则该组试验无效。( F)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î三、选择题'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î1.水泥实验室温度为( ),相对湿度不低于( ),养护箱的温度为( )。相对湿度不低于('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î20℃±2℃、50%、20℃±1℃、95%、B. 20℃±1℃、50%、20℃±2℃、95%、'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îC. 20℃±2℃、50%、20℃±1℃、90%、D.20℃±2℃、50%、20℃±1℃、95%、'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î2.影响水泥体积安定性的因素主要有:( AD)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、熟料中氧化镁含量 B、熟料中硅酸三钙含量 C、水泥的细度 D、水泥中三氧化硫含量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î3、粉煤灰的技术指标包括(ABCD )。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、细度 B、需水量比 C、烧失量 D、三氧化硫含量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
4、硅酸盐水泥的运输和储存应按国家标准规定进行,超过( B )的水泥须重新试验。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、一个月'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、三个月'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、六个月'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、一年'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î5.用负压筛法测定水泥细度时,负压在('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)pa范围内正常'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、3000-4000'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、4000-5000'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、4000-6000'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、5000-6000'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î6水泥胶砂强度试件在抗压试验时。以('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)的速率均匀加载直至破坏。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、240N/S±20 N/S'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、2400N/S±200 N/S'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、50N/S±10 N/S'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、50N/S±5N/S'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î7水泥胶砂3天强度试验应在( B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)时间里进行。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、72h±30min'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、72h±45min'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、72h±1 h'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、72h±3 h'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î8、水泥实验室温度为( ),相对湿度不低于( ),养护箱的温度为( )。相对湿度不低于('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î20℃±2℃、50%、20℃±1℃、95%、B. 20℃±1℃、50%、20℃±2℃、95%、'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îC. 20℃±2℃、50%、20℃±1℃、90%、D.20℃±2℃、50%、20℃±1℃、95%、'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î9.水泥胶砂强度试验中一般情况以('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D )个抗压强度测定值的算术平均值为实验结果。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA 、3'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、4'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、5'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、6'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î10.当坍落度为12cm的水泥混凝土抗压强度试件成型时,采用(B)方法成型。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA 振动台法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B 人工插捣法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C 二者兼用'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î11.混凝土拌合物应在15分钟内成型完,对于成型试模尺寸为150*150*150mm3的混凝土试件,应分( C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)层插捣,每层插捣( C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.3,25'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、2,25'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、2,27'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、3,27'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î12.采用相对用量法表示混凝土配合比时,应以(D)为1,按“水泥:水:细集料:粗集料表示。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、细集料质量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、粗集料质量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、水的质量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、水泥质量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î13.路面水泥混凝土配合比设计以(B )为指标。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA 、抗压强度'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、抗弯拉强度'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、抗弯强度'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î14.原材料确定时,影响混凝土强度的决定性因素是(B)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
a.水泥用量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
b.水灰比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
c.骨料的质量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î15.测定混凝土凝结时间,采用的方法( C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.沉入度法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、压入法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、贯入阻力法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、震动法'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î16.水泥混凝土试模应符合《混凝土试模》(JG3019)中技术规定,应定期进行自检,自检周期宜为 B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
个月。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、二'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、三'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、四'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î17.坍落度小于(C)的新拌混凝土,采用维勃稠度仪测定其工作性。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、20mm B、15mm C、10mm D、5mm'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
18、通常情况下,混凝土的水灰比越大,其强度( B )。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、越大 B、越小 C、不变 D、不一定'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
19、混凝土配合比设计时必须按耐久性要求校核(D )。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、砂率 B、单位水泥用量 C、浆集比 D、水灰比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
20、抗渗混凝土是指其抗渗等级等于或大于('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)级的混凝土。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、P4'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、P6'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、P8'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、P10'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î21.水泥混凝土抗压强度试验时,进行强度计算, 当3个试件中任何一个测值与中值的差值超过中值的(B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)时,则取中值为测定值。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
10%'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B15%'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C 20%'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D25% '¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î22.水泥混凝土抗压强度试验时应连续均匀加载,当混凝土强度等级≥C30,且<C60时,加荷速度应为( C'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.0.2-0.5MPa'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、0.3-0.5MPa'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、 0.5-0.8MPa'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、0.8-1.0MPa'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î23.水泥混凝土试配强度计算涉及到哪些因素 ( ABCD'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.混凝土设计强度等级'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、水泥强度等级'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、施工水平'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
D、强度保证率'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î24.原材料确定时,影响混凝土强度的决定性因素是( B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îa.水泥用量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
b.水灰比'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
c.骨料的质量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î25.在工程中,通常采用'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
来表示水泥混凝土的弹性模量。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA、初始切线弹性模量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、割线弹性模量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、切线弹性模量'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î26.测定水泥混凝土的弹性模量时,所加的最大荷载为轴心抗压强度('¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
1/2'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
B、1/3'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
C、1/4'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î27、立方体抗压强度标准值是混凝土抗压强度总体分布中的一个值,强度低于该值得百分率不超过(C )。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、15% B、10% C、5% D、3%'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
28、以下品种水泥配制的混凝土,在高湿度环境中或永远处在水下效果最差的是(B )。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î
A、普通水泥 B、矿渣水泥 C、火山灰水泥 D、粉煤灰水泥'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î29.混凝土采用较低的水灰比,则混凝土(AC)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îA.较为密实'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îB.强度较低'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îC.耐久性较好'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/îD.节省投入费用'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î四、计算题'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î混凝土计算配合比为1:2.36:4.43,水灰比为0.52,试拌调整时,增加了5%的水泥浆用量。试求:'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(1)混凝土的基准配合比(不能用假定密度法)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(2)若已知以试验室配合比配制的混凝土每立方需用水泥320Kg,求1m3混凝土中其他材料的用量。'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(3)如施工工地砂、石含水率分别为5%、1%,试求现场拌制400L混凝土各种材料的实际用量,'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î(计算结果精确至1 Kg)'¤A¤Ë?^e:bbs.3c3t.com¿7Ö×
÷p/î