mso-hansi-font-family:"Times New Roman"">一、简介:
mso-hansi-font-family:"Times New Roman"">混凝土膨胀砂浆的竖向膨胀率测定仪是根据国标GB50119-2003(GB50119-2013)混凝土外加剂应用设计规范,本规范适用于普通减水剂、高效减水剂、引气剂、引气减水剂、缓凝剂、缓凝减水剂、缓凝高效减水剂、早强剂、早强减水剂、防冻剂、膨胀剂、泵送剂、防水剂及速凝剂等十四种外加剂在混凝土工程中的应用,本实验方法适用于灌浆用膨胀砂浆的竖向膨胀率的测定。
mso-hansi-font-family:"Times New Roman"">二、灌浆竖向膨胀率测定仪技术参数:
1、千分表:量程0-10mm mso-hansi-font-family:"Times New Roman"">(指针 数显);
2、玻璃板:长99× mso-hansi-font-family:"Times New Roman"">宽99× "Times New Roman"">厚5mm(新标准:长140× mso-hansi-font-family:"Times New Roman"">宽80× "Times New Roman"">厚5mm);
3、试模:100×100×100立方体精工试模,拼装缝应填入黄油,不得漏水;
4、铲勺:宽60mm "Times New Roman"">长160mm;
5、捣板:可用钢锯条代替;
6、钢垫板:长320× mso-hansi-font-family:"Times New Roman"">宽180× "Times New Roman"">厚12mm普通钢板;
mso-hansi-font-family:"Times New Roman"">三、安装:
1、钢垫板:表面平整,水平放置在工作台上,水平度不应超过0.02 mso-hansi-font-family:"Times New Roman"">;
2、试模:放置在钢垫块上,不可摇动;
3、玻璃板:平放在试模中间位置。其左右两边与试模内侧边留出10mm mso-hansi-font-family:"Times New Roman"">空隙;
4、数显千分表、百分表与表架卡头固定牢靠。但表杆能够自由升降。安装百分表时,要下压表头,百分表不可前后左右倾斜;
5、千分表架固定在钢垫板上,尽量靠近试模,缩短横杆悬臂长度。
mso-hansi-font-family:"Times New Roman"">四、灌浆竖向膨胀率测定仪试验方法与步骤:
1、灌浆料用水量按流动度为250±10min的用水量;
2、灌浆料加水搅拌均匀后立即灌模。从玻璃板的一侧灌入。当灌到50mm mso-hansi-font-family:"Times New Roman"">左右高度时,用捣板在试模的每一侧插捣6 mso-hansi-font-family:"Times New Roman"">次,中间部位也插捣6 "Times New Roman"">次。灌到90mm "Times New Roman"">高度时,和前面相同再做插捣,尽量排除气体。**后一层灌浆要一次灌至两侧流出灌浆料为止。要尽量减少灌浆料对玻璃板产生的向上冲浮作用;
3、玻璃板两侧灌浆料表面,用小刀轻轻抹成斜坡,斜坡的高边与玻璃相平。斜坡的底边与试模内侧顶面相平。抹斜坡的时间不应超过30S mso-hansi-font-family:"Times New Roman"">。成型温度、养护温度均为(20±3 "Times New Roman"">)℃;
4、做完斜坡,把百分表测量头垂放在玻璃板上,在30S mso-hansi-font-family:"Times New Roman"">内记录千分表度数。为初始读数。
5、测定初始读数后30S mso-hansi-font-family:"Times New Roman"">内,玻璃板两侧灌浆料表面盖上二层湿棉布;
6、从测定初始读数起,每隔2h mso-hansi-font-family:"Times New Roman"">浇水1 "Times New Roman"">次。连续浇水4 "Times New Roman"">次。以后每隔4h "Times New Roman"">浇水1次。保湿养护至要求龄期,测定3d mso-hansi-font-family:"Times New Roman"">、7d "Times New Roman"">试件高度读数;
7、从测量初始读数开始,测量装置和试件应保持静止不动,并不受振动。
mso-hansi-font-family:"Times New Roman"">五、竖向膨胀率应按下式进行计算:
mso-hansi-font-family:"Times New Roman"">式中
t——竖向膨胀率;
h0——试件高度的初始读数(mm mso-hansi-font-family:"Times New Roman"">);
ht——试件龄期为t mso-hansi-font-family:"Times New Roman"">时的高度读数(mm "Times New Roman"">);
h——试件基准高度100 mso-hansi-font-family:"Times New Roman"">(mm "Times New Roman"">)。
mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0pt;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA">试验结果一组三个试件的算术平均值,计算精确至 mso-fareast-font-family:宋体;mso-font-kerning:1.0pt;mso-ansi-language:EN-US; mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA">10-2 "Times New Roman";mso-font-kerning:1.0pt;mso-ansi-language:EN-US;mso-fareast-language: ZH-CN;mso-bidi-language:AR-SA">。