混凝土拌合物实验
一、实验目的：熟悉混凝土拌和物和易性的检测方法及影响混凝土拌和物和易性的因素，能够根据实验结果分析原因并提出措施，通过试拌调整确定混凝土基准配合比。
Purpose: Familiar concrete mixture workability test methods and workability of concrete mixture factors influence the ability to analyze the reasons and propose measures to adjust the benchmark to determine by trial mix concrete mix according to the experimental results. 二、实验仪器：
1、拌合物和易性：坍落度筒、捣棒、坍落度尺、钢尺、维勃稠度仪、秒表。
2、混凝土立方体抗压实验：压力实验机、钢制垫板、立方体试模、标准养护室、捣棒、小铁铲、钢尺。Laboratory equipment:
Mixing material workability: slump cone, tamping rod, slump ruler, ruler, Weibo consistency meter, stopwatch.
Concrete cube compressive test: pressure testing machine, steel plate, cube test mode, the curing room, tamper, small shovel, steel ruler.
三、实验原理：混凝土拌合物的性能直接关系到施工工艺的选择及混凝土的施工质量，对硬化后混凝土的物理力学性能也有重大影响。Principle: The performance concrete mixture is directly related to the quality of construction and concrete construction technology of choice, but also have a significant effect on the mechanical properties of the hardened concrete physical.
四、实验内容及步骤： 1、混凝土拌合物的拌制 一般规定：
① 在混凝土实验室内拌和混凝土时，室温应保持在20±5℃，所拌制的混合物应避免阳光直射。
② 拌合物所用的各种材料的温度应与室温相同。 ③ 拌和混凝土用的各种工具应保持洁净和湿润。 ④ 材料用量以质量计，称量精度满足要求。
⑤ 砂石骨料用量以饱和面干状态或干燥状态为基准。Fourth, experimental content and steps:
1, mixing concrete mixture General provisions:
① When mixing concrete in the concrete laboratory, room temperature should be maintained at 20 ± 5 ℃, the mixing of the mixture should avoid direct sunlight.
Temperature ② mixing materials used in various materials at room temperature should be the same.
③ mixing concrete with a variety of tools should be kept clean and moist. ④ amount of material by mass, weighing accuracy to meet the requirements. ⑤ Aggregate amount of saturated surface dry state or a dry state basis. 2、拌合物和易性实验 （1）坍落度实验
通过坍落度实验确定拌合物流动性，并在实验中观察判定粘聚性和保水性的好坏。 实验步骤：
① 湿润坍落度筒的内壁和拌和钢板，将筒放在钢板上，用双脚踏紧踏板。
② 将拌和好的混凝土分三层装如筒内，每层大致为筒高1/3。 ③ 每层均匀插捣25次，底层插到底，上层插入下层10-20mm。 ④ 表面摸平，清除周围混凝土。 ⑤ 在5-10s内提起坍落度筒，且从装料到提起坍落度筒的整个操作过程应在150s内完成。
⑥ 将坍落度筒放于试样旁边，量出筒高与试样最高点之差，即为坍落度。量测精确到1mm，结果表达精确到5mm。
⑦ 提起坍落度筒后，如果出现崩坍或一边剪切，应重做实验；如果再次出现上述现象，则表示混凝土粘聚性和保水性不良。
⑧ 实验的同时观察粘聚性和保水性。Mixing material workability test ( 1 ) Experimental slump
Slump determined experimentally by mixing physical mobility, and observe determine cohesiveness and water retention is good or bad in the experiment.
Experimental procedure:
① steel wall and the wet mixing of the slump cone , on the plate cylinder , a tight double foot pedal .
② The three layers of concrete mixing equipment such as a good barrel , each barrel is approximately 1/3 higher .
③ 25 times each pound evenly inserted , the bottom plug in the end , the upper insert the lower 10-20mm.
④ touch the flat surface , remove the surrounding concrete .
⑤ filed slump cone in the 5-10s, and is expected to bring the whole process from the loading operation slump cone should be completed within 150s.
⑥ The slump cone placed next to the sample , a high measure out the difference between the highest point of the tube specimen , namely slump . Measurements accurate to 1mm, expressing the results accurate to 5mm.
⑦ filed after slump cone , landslides or if one side cut , you should redo the experiment ; If the above phenomenon again , it means that concrete cohesion and protect poor water retention.
⑧ experiments while observing the cohesiveness and water retention . （2）维勃稠度实验
对干硬性混凝土的流动性实验采用此法。 实验步骤：
① 将容量筒固定于振动台上，把坍落度筒放入容量筒内并对中；然后，把漏斗旋转到筒顶位置，并把它座落在坍落度筒的顶上，，拧紧螺丝，保证坍落度筒不能离开容量筒底部。
② 将拌和好的混凝土分三层装入坍落度筒，装料和捣实方法与“坍落度实验”相同。顶层插捣完毕后，松开螺丝，移开漏斗，再拧紧螺丝，将顶面刮平。
③ 将坍落度筒缓慢提起，混凝土拌合物慢慢坍陷。然后，放松螺丝，将透明圆盘转到混凝土锥体商埠，小心降下圆盘直至与混凝土的顶面接触，拧紧螺栓，从滑杆的刻度上读出坍落读数值。
④ 重新拧紧螺丝，放松螺栓，开动振动台，同时用秒表计时，当透明圆盘的整个底面都与水泥浆接触时，记录秒表读数——即混凝土拌合物的维勃稠度值。) Weibo consistency test
On dry concrete fluidity experiments using this method .
Experimental procedure:
① the capacity of the cylinder is fixed on the vibration table , the slump cone into the barrel and the capacity ; Then, the cylinder is rotated to the top of the funnel position and it is located at the top of the slump cone and tighten screws, can not leave the bottom of the slump cone to ensure capacity cartridge.
② The good mixing concrete slump cone of three loading , loading and tamping methods and \" slump test \" the same . Plug the top pound finished, loosen the screws , remove the funnel , and then tighten the screws , the top surface evenness .
③ slowly lift the slump cone , concrete mixture slowly collapse . Then , loosen the screws , the transparent disc to concrete cone commercial port , carefully lowered until contact with the top surface of the disc concrete, tighten the bolts , read from the slump on the slider scale readings .
④ re- tighten the screws , loosen bolts, start shaking table , but with a stopwatch timing , when the entire bottom surface of the transparent disk are in contact with water, mud, recorded stopwatch readings - that is, the value of Weibo consistency of concrete mixture
3、混凝土立方体抗压强度实验
混凝土立方体抗压强度实验的目的是检验混凝土的抗压强度是否满足设计要求。我国采用150mm立方体试件为标准立方体时间。
实验步骤：
① 按规定方法制作并养护混凝土时间。
② 达到实验龄期时，从养护室取出时间，并尽快实验。实验前需用湿布覆盖时间，防止试件内的温度、湿度发生显著变化。
③ 实验前，将试件擦拭干净，检查外观，测量尺寸，并据此计算受压面积。当时测尺寸与公称尺寸之差不超过1mm时，可按公称尺寸计算受压面积。试件承压面的平整度要求与试模的要求相同。当试件有严重缺陷时，应废弃。
④ 将试件放在实验机下的压板的正，上下压板与试件间宜加垫板，加压方向与试件成型时的捣实方向垂直。
⑤ 加荷应均匀连续进行，加荷速度：混凝土强度等级低于C30时，按0.3~0.5MPa/s加荷；高于或等于C30时，按0.5~0.8MPa/s加荷。当试件接近破坏时，应减缓油门，直至试件破坏。记录破坏荷载P(N)。
⑥ 按下式计算抗压强度：fcPA
⑦ 以3个时检测值的算术平均值作为该组试件的实验结果。3个测值的最大值、最小值中，若有1个测值与中间值之差超过中间值的15%，则取中间值作为实验结果。若两个测值都超过中间值的15%，则此组试件作废。Concrete cube compressive strength test
The purpose of the experiment is the concrete cube compressive strength of concrete compressive strength test meets the design requirements. Our 150mm cube specimens using standard cubic time .
Experimental procedure:
① production methods and curing of concrete required time .
② reach the age when the experiment , the time taken from the curing room , and the experiment as soon as possible . Before the experiment the time required to cover a damp cloth , to prevent the temperature inside the test piece , a
significant change in the humidity .
③ before the experiment , the specimen will be wiped clean, check the appearance , measurements and calculate pressure area . Was measured when the difference between the nominal size and the size of no more than 1mm, calculated according to nominal size pressure area . Specimen bearing surface flatness requirements and tryout the same requirements . When the specimen was seriously flawed and should be discarded.
④ direction between the tamping plate specimens experimental aircraft placed under the center of the upper and lower platen and specimen should not be treated plate , pressing the direction perpendicular to the specimen molding .
⑤ should be uniform continuous loading , loading rate : less than when the concrete strength grade C30, by 0.3 ~ 0.5MPa / s loading ; greater than or equal to C30 , press the 0.5 ~ 0.8MPa / s loading . When the specimen close to destruction, should slow down the throttle until the destruction of the sample . Record breaking load P (N).
⑥ compressive strength is calculated as follows :
⑦ arithmetic mean of three values as the detection results of the group of the specimen. Maximum of three measured values , minimum , and if 15% of the measured value and the difference between an intermediate value exceeds the median , then take the middle value as the experimental results. If the two measured values are more than 15% of the median , then this group of specimens void.
