Determination of elastic modulus of concrete structure and method of operation
Concrete modulus determination instrument this determination instrument by Shang ring, Xia ring, contact rod, thousand points table and tight set screws composition. test began Qian, will modulus determination instrument placed Yu flat of plane Shang, spin out try block tight set screws, loaded thousands points table, sent open fixed Board tight set screws, removed fixed Board, is determination instrument has in try block Shang positioning. will determination instrument together with try block placed pressure test machine of Xia plate Shang, try block Center and pressure machine Xia plate Center alignment, thousand points table adjustable 0.
Started pressure machine, dang Shang plate and try pieces close Shi, adjustment ball seat, makes contact balanced, to 0.2-0.3mpa/s of speed continuous and uniform to loaded to Pa (that try pieces expected damage load contains value of 40%), then to also speed unloading load to 0, so repeatedly pre pressure 3 times. in pre pressure Shi, observation pressure machine and the micrometer whether normal. try pieces sides micrometer deformation of poor.
Shall not is greater than deformation average of 15%, more cannot plus or minus different to, dang used 100mmx100mm section of try pieces Shi, its sides deformation of poor, shall not is greater than deformation average of 20%, or with hardwood light knock ball seat adjustment, or adjustment try pieces location. with above speed for fourth times added load, first to early load, first to early load PO (about for 0.5MPA), keep 30S, respectively read sides micrometer o, then added load to PA, keep about 30 seconds, respectively read sides micrometer a,, Calculate deflection value a-o on both sides, and calculate the average, is set to 4 and read at the same speed after unloading a to PO, for about 30 seconds, dial indicator reading of 00 read both sides, respectively, above steps, for the fifth time loading, and 50
5 and 4, should be no larger than the difference of 0.0002 (L=150mm), otherwise, Zhong Fu above steps, until the difference between two adjacent loading and deformation values meet the requirements, subject to deformation value of 0 for the last time. then remove the dial gauge, continued to load to the specimen in the same speed, write down the cyclic axial compressive strength of Ra.
Modulus of elasticity of concrete measuring instrument in line with g-B11971-89 mechanical properties test methods of aerated concrete, and GB81-85 test method of mechanical properties of ordinary concrete, JGJ053-94 of cement concrete in highway engineering test procedures, ASTMC-469. this product conforms to the GB11971-89 the mechanical properties test methods of aerated concrete, and GB81-85 of the test method of mechanical properties of ordinary concrete, JTG-2005 of the cement concrete in highway engineering test procedures, ASTMC-469. mainly used for measuring elastic modulus of concrete block. the apparatus is simple, lightweight, convenient for use at trial.
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