SU881613A1

SU881613A1 - Method of testing reinforcing rod in pulling it out of a concrete specimen

Info

Publication number: SU881613A1
Application number: SU792857256A
Authority: SU
Inventors: Юрий Алексеевич Мамонтов; Иван Андреевич Браун
Original assignee: Казахский Химико-Технологический Институт
Priority date: 1979-12-21
Filing date: 1979-12-21
Publication date: 1981-11-15

Description

(54) СПОСОБ ИСПЫТАНИЯ АРМАТУРНОГО СТЕРЖНЯ(54) METHOD FOR TESTING ARMATURE ROD

ПРИ ВЫДЕРгаВАНИИ ЕГО ИЗ БЕТОННОГО ОБРАЗЦАWHEN TAKING IT OUT OF A CONCRETE PATTERN

1one

Изобретение относитс к строительству и может быть использовано дл определени прочности сцеплени арматуры с бетоном.The invention relates to construction and can be used to determine the strength of adhesion of reinforcement to concrete.

Известен способ испытани арматурного стержн при выдергивании его из бетонного образца, включающий его закрепление на опорной плите, приложение выдергивающей нагрузки на арматурный стержень и фиксацию момента нарушени акустическими приборами l .There is a known method of testing a rebar when pulling it out of a concrete sample, including its fastening on the base plate, the application of a pulling load on the rebar and fixing the moment of violation by acoustic devices l.

Недостатком такого способа вл етс сложность обслуживани дефицитных акустических приборов.The disadvantage of this method is the difficulty of servicing scarce acoustic devices.

Наиболее близким техническим решением к изобретению вл етс способ испытани арматурного стержн при выдергивании его из бетонного образца ,, включающий закрепление бетонного образца на опорной плите и приложение выдергивающей нагрузки на арматурный стержень .The closest technical solution to the invention is a method for testing a rebar when pulling it out of a concrete sample, which includes fixing a concrete sample on a base plate and applying a pulling load to the rebar.

Недостатком этого способа вл етс низка точность фиксации усили в момент нарушени сцеплени по всей поверхности контакта.The disadvantage of this method is the low accuracy of fixing the force at the time of adhesion across the entire contact surface.

Цель изобретени - повьш1ение точности испытаний.The purpose of the invention is to increase the test accuracy.

Поставленна цель достигаетс тем, что согласно способу испытани арматурного стержн при выдергивании его из бетонного образца, The goal is achieved by the fact that, according to the method of testing the reinforcing rod when pulling it out of the concrete sample,

10 включающем закрепление бетонного образца -на опорной плите и приложение выдергивающей нагрузки на арматурный стержень, приложение выдергивающей нагрузки на арматурный стержень 10 including the fixing of the concrete sample - on the base plate and the application of the pulling load on the rebar, the application of the pulling load on the reinforcing bar

15 осуществл ют пружиной, предварительно сжатой прессом, причем увеличение выдергивающей нагрузки производ т путем уменьшени сжимающего усили передаваемого процессом на пружину, 15 is carried out by a spring pre-compressed by a press, wherein an increase in the pulling load is produced by reducing the compressive force transmitted by the process to the spring,

Claims

20 and the moment of failure of the reinforcement rod to adhere to the concrete specimen, fic | sirut, by abrupt increase / pressing force. FIG. -1 shows a diagram of a device for pulling the reinforcement out of a concrete sampleJ in FIG. 2 scheme of compression of the spring press; in fig. 3 is a diagram of pulling a rebar from a concrete sample. Concrete sample 1 with reinforced core 2 concreted in the center is mounted on a fixed base plate 3. On concrete sample 1 there is a spring 4 with a movable plate 5 having a central hole 6 and equipped with devices 7. The plate 5 is passed into the rebar 2 and secured with a collet gripper 8. Welded frame 9 is installed between plate 5 and the press (fig. not shown), Example. The press produces a slip of the spring 4 and a fixation of the degree of compression with the aid of the instruments 7 and the corresponding compressive deformations of the forces, which are set according to the indications of the press pressure gauge. After compressing the spring 4 on the reinforcement rod, it does not fasten 2): the collet grip 8, then smoothly reduces the force developed by the press, and promotes the release of the clamp and transfers the pull-out; force through the collet grip 8 on the reinforcing bar 2. The force in the reinforcing bar 2 is defined as the difference between the force of the pruekin determined by the degree of its compression and the force of the press. At the time of the clutch failure across the contact surface, the force in the reinforcement becomes zero . At this moment, the force of the spring is balanced only by the force of the press, which causes a sharp abrupt increase in the force of the press, which has decreased before. The method makes it possible to more accurately determine the strength of adhesion of the reinforcement to the concrete. Claim Method Testing a rebar while stripping it from a concrete sample, including securing the concrete sample to a base plate and applying a pulling load on the rebar, characterized in that, in order to increase the test accuracy, the application of the pulling load on the rebar is carried out by spring, previously compressed by the press, and the increase in pulling load is produced by reducing the compressive force transmitted by the press to the spring, and the moment of violation with the adhesion of the reinforcing bar with the concrete sample is fixed by a stepwise increase in the pressing force. Sources of information taken into account during the examination 1. USSR author's certificate No. 188744, cl. GO N 49/02, 9b4.

2. Strength, deformability and crack resistance of reinforced concrete. Rostov-on-Don, ed. Rostov State. University, 1969, p. 52-53.

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