Cement elastic modulus tester 水泥弹性模量测定仪

TM-3 cement elastic modulus tester

1、 Overview:

TM-3 elastic modulus tester complies with gb1971-89 test method for mechanical properties of aerated concrete, gb81-85 test method for mechanical properties of ordinary concrete, jgj053-94 test code for cement concrete of highway engineering and astmc-469. It is mainly used to measure the elastic modulus of concrete test block. The instrument is simple, lightweight and easy to use in the test.

2、 Main technical parameters:

1. Applicable to concrete elastic modulus test block forty × forty × 160mm

2. Dial indicator range 0-1mm

3. Center distance between upper and lower rings 150mm

4. Distance from bottom of lower ring 75mm

3、 Structure and operation method:

The tester is composed of upper ring, lower ring, contact rod, dial indicator and set screw (see attached figure)

Before the test, place the elastic modulus tester on a flat plane, screw out the set screw of the test block, install the dial indicator, send out the set screw of the fixing plate, and remove the fixing plate, then the tester has been positioned on the test block. Place the tester together with the test block on the lower pressing plate of the pressure testing machine, align the center of the test block with the center of the lower pressing plate of the press, and zero the dial indicator. Start the press. When the upper pressing plate is close to the test piece, adjust the ball seat to make the contact balanced, load it continuously and evenly to pa (i.e. 40% of the expected failure load value of the test piece) at the speed of 0.2-0.3mpa/s, and then unload it to zero at the same speed. Repeat preloading for 3 times. During preloading, observe whether the press and dial indicator are normal. The deformation difference of dial indicators on both sides of the test piece shall not be greater than 15% of the average value of deformation, let alone positive and negative opposite directions. When 100mm is used × For the test piece with 100mm section, the difference of deformation on both sides shall not be greater than 20% of the average value of deformation, otherwise tap the ball seat with hardwood to adjust or adjust the position of the test piece. Apply the load for the fourth time at the above speed, first to the initial load, first to the initial load Po (about 0.5MPa), keep it for 30s, read the dial indicator △ o on both sides respectively, then apply the load to PA, keep it for about 30s, read the dial indicator △ a on both sides respectively, calculate the deformation increment △ a - △ o on both sides respectively, calculate the average value and set it as △ 4; After reading △ a, unload to Po at the same speed and keep it for about 30 seconds. Read the readings of dial indicators on both sides △ 00 respectively. Carry out the fifth loading in the same steps as above, and calculate that the difference between △ 50 △ 5 and △ 4 shall not be greater than 0.0002 (L = 150mm). Otherwise, follow the above steps until the difference between the deformation values of two adjacent loads meets the requirements, and the deformation value △ 0 after Z shall prevail. Then remove the dial indicator, continue loading at the same speed until the specimen is damaged, and record the cyclic axial compressive strength RA.

TM-3水泥弹性模量测定仪 
一、概述：
TM-3弹性模量测定仪符合G B11971-89〈加气砼力学性能试验方法〉、 GB81-85〈普通砼力学性能试验方法〉、JGJ053-94〈公路工程水泥砼试验规程〉、ASTMC-469。主要用于测量砼试块的弹性模量。本仪器简单、轻巧、便于试验中使用。
二、主要技术参数：
1、适用砼弹性模量试块...40×40×160mm
2、千分表量程.......0-1mm
3、上、下环中心距.......150mm
4、下环离底部距离.........75mm
三、结构及操作方法：
本测定仪由上环、下环、接触杆、千分表和紧定螺钉组成，（参见附图）
试验开始前，将弹性模量测定仪放置于平整的平面上，旋出试块紧定螺钉，装上千分表，送开固定板紧定螺钉，取下固定板，则测定仪已在试块上定位。将测定仪连同试块置于压力试验机的下压板上，试块中心与压力机下压板中心对准，千分表调零。开动压力机，当上压板与试件接近时，调整球座，使接触均衡，以0.2-0.3mpa/s的速度连续而均匀地加载到Pa（即试件预期破坏荷载值的40%），然后以同样速度卸荷至零，如此反复预压3次。在预压时，观察压力机及千分表是否正常。试件两侧千分表变形之差，不得大于变形平均值的15%，更不能正负异向，当采用100mm×100mm截面的试件时，其两侧变形之差，不得大于变形平均值的20%，否则用硬木轻敲球座调整，或调整试件位置。用上述速度进行第四次加荷，先至初载荷,先至初载荷PO（约为0.5MPA），保持30S，分别读两侧千分表△O，然后加荷至PA，保持约30秒，分别读两侧千分表△A，分别计算两侧变形增值△A-△O，并计算出平均值，设为△4；读取△A后即以同样速度卸荷至PO，保持约30秒，分别读两侧千分表读数△00，同上步骤，进行第五次加荷，求出△50 △5与△4之差应不大于0.0002（L=150mm),否则，应中伏上述步骤，直至两次相邻加荷变形值之差符合要求，以z后一次变形值△0为准。然后卸去千分表，以同样速度继续加荷至试件破坏，记下循环轴心抗压强度Ra。