Concrete strength test rebound hammer original schmidt live. Estimate concrete strength using rebound hammer fprimec. The manufacturer shall report the rebound number to be obtained by a properly operating instrument when tested on an anvil of specified hardness. Rebound hammer is also known as schmidts hammer or swiss hammer as it is invented by ernst schmidt, a swiss engineer. By referring to the some conversion tables, the rebound result of the test can be used to determine the compressive strength of the concrete. The rebound hammer has been around since the late 1940s and today is a commonly used method for estimating the compressive strength of inplace concrete. Statistical case study on schmidt hammer, ultrasonic and core. Rebound values are read from a scale for subsequent calculation of the mean. Locations having very low rebound numbers indicate weak surface concrete and may be affected by corrosion. Rebound hammer test is the most appropriate and useful testing methods for comparing the relatively weaker and stronger areas of concrete. The device used in the test known as schmidt hammer or rebound hammer, uses a spring and measures the hardness of concrete surface using the rebound principle 2. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Procedure for rebound hammer test procedure for rebound hammer test on concrete structure starts with calibration of the rebound hammer. If the situation demands,the rebound hammer can be.
This device is universally used because of a hardened steel hammerimpacted on the concrete by a spring. Pdf rebound hammer test method statement rusi sumdaram. It was invented by ernst schmidt, a swiss engineer. To reduce these limitations of the schmidt test result has to be correlated with results of destructive test methods. The surface of hardened concrete is struck with the hammer, and concrete compressive strength is estimated via the surface hardness rebound value.
This methods not only are being used to evaluate the compression strength but for detecting defects like cracks. Typically, a rebound hammer will result in a rebound number of 80 2 when tested on the anvil described in section 4. Rebound hammer test rebound hammer test is done to find out the compressive strength of concrete by using rebound hammer as per is. Review of the rebound hammer method estimating concrete. The rebound depends on the surface hardness of the concrete and is measured by test equipment. A number in parentheses indicates the year of last. The test can thus be conducted horizontally on vertical surfaces or vertically upwards or downwards on horizontal surfaces.
Rebound hammer might provide some information on concrete quality provided that it is calibrated on. All concrete test hammers measure the surface hardness of the material they are testing. The most recent results of scientific research show that the. Standard test method for rebound number of hardened. Test procedure is simple and equipment is portable and easy to operate. Ceyhan limestone, barbaros marble, antique cream limestone, osmaniye marble, toprakkale basalts, and handere sandstone. The schmidt hammer is equipped with a sensor which measures the rebound value of a test impact to high resolution and repeatability. Each component fit together and is calibrated as one unit as shown in the figure 1 below. The final results showed an acceptable accuracy of the calibration curve in the prediction of the compressive strength of re material.
Report of rebound hammer test free download as word doc. The manual concrete test hammer, aka rebound hammer, schmidt hammer, swiss hammer, sclerometer, is the most widely used non destructive instrument for compressive strength determination. Application of rebound hammer method for estimating. Report of rebound hammer test concrete applied and. Schmidt rebound hammer were made and used around the world 18. Laboratory manual imam abdulrahman bin faisal university. Perform a few test impacts with the concrete test hammer on a smooth. This is undoubtedly the most commonly ndt test used to quickly assess the condition of a concrete structure. Rebound hammer test procedure for concrete hardness. Schmidt rebound hammers, concrete test hammers, ndt. A number in parentheses indicates the year of last reapproval. C805 c805m18 standard test method for rebound number of hardened concrete rebound number insulating boards springdriven steel hammers.
The rebound reading on the indicator scale has been calibrated by the manufacturer of the rebound hammer for horizontal impact, that is, on a vertical surface, to indicate the compression strength. Over the years, its application has been extended to test rocks and hardness tests of paper reels. Rebound hammer is also known as schmidt s hammer or swiss hammer as it is invented by ernst schmidt, a swiss engineer. This makes your test results easier to read, as it will also lock the indicator. Schmidt hammer is in not a standard test for acceptance testing of concrete strength. Surface hardness measured during the test give an idea about the soundness and quality of cover concrete. Schmidt hammer test pdf estimate the compressive strength of concrete is the rebound hammer test, also known as schmidt hammer test. You will hear a click, and the piston will extend into the test position.
Pdf the schmidt hammer in rock material characterization. Pdf application of rebound hammer method for estimating. Standard test method for rebound number of hardened concrete. Sep 18, 20 interpretation of results of rebound hammer the rebound reading on the indicator scale has been calibrated by the manufacturer of the rebound hammer for horizontal impact, that is, on a vertical surface, to indicate the compression strength. Among ndt method to evaluate concrete status, schmidt hammer test and ultra sonic test are more popular in the region of study. It is only a test used for estimating the strength of concrete in structure and it can hardly be considered as a substitute for compressive strength test. Then the compressive strength was ascertained on a pressure testing machine. Is schmidt hammer test a standard test for testing concrete. The original schmidt, the worlds first and now most widely used test hammer for. The rebound of an elastic mass depends on the hardness of the surface against which its mass strikes. Standard test method for determination of rock hardness by. With the schmidt hammer, various parameters such as impact direction, form factor and time factors such as carbonation depth can easily be set. It has two distinct advantages over the original schmidt.
Introduction digi schmidt rebound hammer is also a useful tool to determine the surface hardness of concrete. Jun 10, 2016 the hm75 schmidt concrete rebound test hammer provides rapid nondestructive estimates of inplace concrete strength and is a valuable tool when assessing the need for further testing. A simple equipment known as rebound hammer or schmidt hammer is used for this purpose. For taking a measurement, the rebound hammer should be held at right angles to the surface of the concrete member. Type n hammer is also used for the testing of massive rock. Records gps locations, enables adding notes, images and audio comments using the logbook. Rebound hammer test is conducted around all the points of observation on all accessible faces of the structural element. Using the humboldt concrete rebound hammer always hold the concrete rebound hammer in both hands while in use. When using the rebound hammer, the limitations of the test method should be recognized and taken into account.
In each test, at least 10 test hammer impacts were performed on one. To perform a test, make sure the piston is extended and gently press the rebound hammer against the concrete surface to be tested. May 27, 2018 rebound hammer test schmidt s hammer a non destructive test on concrete surface hardness test duration. When used in any other position, appropriate correction as given by the manufacturer is to be taken into account. A schmidt hammer, also known as a swiss hammer or a rebound hammer or concrete hammer test, is a device to measure the elastic properties or strength of concrete or rock, mainly surface hardness and penetration resistance. Procedure rebound number will indicate that the surface of the. For taking a measurement, the rebound hammer should be held at right angles to them surface of the concrete member. Calibration and use of impact test hammer, proceedings, american concrete institute, vol 54, august 1957, pp. Proper use of the rebound hammer updated to reflect the. Digital rebound hammers for the quick and easy determination of the strength of concrete, and hardness of construction materials.
Proceqs original schmidt live concrete strength test rebound hammer is the worlds most advanced rvalue concrete test hammer unrivaled for testing, reporting and analysis of concrete strength and uniformity. For this, the rebound hammer is tested against the test anvil made of steel having brinell hardness number of about 5000 nmm2. Concrete test hammer, ideally suited for onsite tests of concrete and is widely used instrument for analyzing the uniformity and compressive strength characteristics of concrete structures and detection of weak spots in the concrete. Before starting the procedure calibration of the hammer is required. To do this, the schmidt hammer is tested against the steel test anvil which has a brinell hardness number of about 5000mpa. Concrete rebound hammer concrete test rebound hammer.
Procedure for schmidt hammer test or rebound hammer test. In spite of a large number of scientific works trying to calibrate the test, to identify the parameters affecting its results and to estimate its reliability, the original schmidt. The original schmidt os8000 is the original concrete test hammer, now digitally redefined and it is also the most advanced rvalue hammer ever made, with unmatched performance, ease of use, and versatility, as well as reporting on the go thanks to its mobile app. Concrete test hammers swiss precision since 1954 the concrete test hammers are the most widely used portable ndt measuring instruments for a rapid assessment of the condition of a concrete structure. Gupta, niharika gupta and amandeep singh one of the most widely spread techniques to estimate the compressive strength of concrete is the rebound hammer test, also known as schmidt hammer test. Type n schmidt test hammer the type n hammer is designed for testing concrete items 4 100 mm or more in thickness, or concrete with a maximum particle size less than or equal to 1. Application of rebound hammer method for estimating compressive.
Around each point of observation, six readings of rebound indices are taken and average of these. The rebound values r of the sample cubes were measured using the concrete test hammer. Schmidt hammer test or rebound hammer test of concrete. The digi schmidt concrete test hammer consists of the actual concrete test hammer and the display unit. A free powerpoint ppt presentation displayed as a flash slide show on. Rebound hammer test schmidt hammer testing on concrete. Nondestructive testing of concrete methods of test. Astm c805, standard test method for rebound number of hardened concrete, summarizes the procedure as a steel hammer impacts, with a predetermined. Nondestructive testing of concrete by rebound hammer.
In the procedure of rebound hammer test, the plunger of rebound hammer is pressed on the surface of concrete, so that a spring controlled mass with a constant energy is made to hit the concrete. The schmidt hammer provides a quick and inexpensive measure of surface hardness that is widely used for estimating the mechanical properties of rock material. Put the rebound hammer back together, and test it on the anvil again to get a calibrated reading. Ppt concrete rebound hammer powerpoint presentation. Schmidt rebound hammer test the schmidt rebound hammer is principally a surface hardness tester. Yasar and erdogan 2004a derived the following empirical correlation between them based on the test results of six different rock types. All of the concrete rebound hammers we carry below accurately measure compressive strength of concrete, which directly determines the loadbearing capacity and durability of concrete structures. Estimating the strength of concrete using surface rebound. Rebound hammer test on concrete principle, procedure.
Utc3032 concrete test hammer original schmidt type n proceq is used to measure the compressive strength characteristics of hardened concrete nondestructively, control uniform concrete quality and detect weak spots in the concrete. The hm75 schmidt concrete rebound test hammer provides rapid nondestructive estimates of inplace concrete strength and is a valuable tool when assessing the need for further testing. Assessing the rebound hammer test for rammed earth. Clean the surface of concrete, ensure the concrete is clean and dirt free. The rational use of the various available methods, as well as a possible combination of more than one method, can be particularly interesting from the viewpoint of the validity of results. The rebound hammer test is codified in astm c805 3 and csn en 125042 4. Acceptability of rebound hammer test is evaluated by different research works and studies. It is one of the most useful non destructive techniques in evaluation of concrete structures.
It works on the principle that the rebound of an elastic mass depends on the hardness of the surface against which the mass impinges. Pdf the rebound hammer strength test, being a nondestructive test, has its advantages of preserving integrity of sample. Standard test method for rebound number of hardened concrete1. The rebound hammer developed by schmidt provides an inexpensive and quick method for nondestructive testing of concrete.
The schmidt hammer test involves hitting the insitu concrete with a springdriven pin at a defined energy, and then the rebound is measured. Astm c805 c805m 18 standard test method for rebound. Case study of strength evaluation of structural concrete. Rebound hammer test schmidt s hammer a non destructive test on concrete surface hardness test duration. With the aid of the test hammer the quality of the concrete in every part of a construction can quickly be examined, and in this time the hardening of the various castings can.
Typically, a rebound hammer will result in a rebound number of. Aug 05, 2018 procedure for schmidt hammer test or rebound hammer test. The functionality of the rebound hammer shall have been verified in accordance with 6. Doc rebound hammer test result prince patwa academia. Schmidt hammer rebound number is higher as density or unit weight increases. Digital rebound hammers testing compressive strength and. All about structural analysis and design 28,5 views. Betonprufhammer bedienungsanleitung sclerometre a beton nnr. Schmidt hammers, or concrete test hammers, are used to determine inplace strength of concrete. Standard test method for determination of rock hardness by rebound hammer method1 this standard is issued under the. Standard test method for rebound number of hardened concrete1 this standard is issued under the. Concrete surfaces are thoroughly cleaned before taking any measurement.
In this section principals of these tests will be presented. Bureau of indian standard did not published any standard for this test upto 1991. Proceqs schmidt hammer portfolio is the most comprehensive available. Is schmidt hammer test a standard test for testing. Developed in 1948 by a swiss engineer named ernst schmidt, the device measures the hardness of concrete surfaces. Firstly the new schmidt hammer measurement using the quotient of the impact and rebound velocities increases the sensitivity in so the hammer test is now possible between 10100mpa and is not effected by gravity making the unit useful in 360deg of operation with no correction. Test can be undertaken on site and the number of test is unlimited.
501 1216 114 770 1036 319 644 1300 969 930 476 1120 533 34 373 957 1160 261 1050 1137 1217 108 1098 582 388 1393 312 770 379 471 56 722 1174 212 1140 1276 1333 857 1400 33 958 1234 71 951 1366 204 1088 1283 782