If the situation demands,the rebound hammer can be. Testing the compressive strength of a concrete cube using schmidt hammer. Concrete testing with the original schmidt hammer is the most frequently used method worldwide for nondestructive testing of concrete and structural components. Pdf rebound hammer test method statement rusi sumdaram. Concrete testing with original schmidt hammer is the most frequently. Nondestructive testing of concrete methods of test. Penetration resistance test astm c 803 engineersdaily. Aug 26, 2019 a schmidt hammer measures the surface hardness and penetration resistance offered by a section of concrete. C 805 97 standard test method for rebound number of hardened concrete1 this standard is issued under the fixed designation c. Utc3045 silver schmidt concrete test hammer pc n type proceq. The hammer is intended for testing the quality of concrete in finished structures such as buildings and bridges. Isodis 8045, en 12 5042, env 206, din 1048 part 2, astm c 805. Review of the rebound hammer method estimating concrete.
Schmidt hammer rebound tests were carried out directly on the faces of the lower and upper coal beds at both the a05 and f02 panels by using a calibrated ltype hammer fig. An instrument guide is provided to center the rebound hammer over the impact area and keep the instrument perpendicular to the surface. The silverschmidt is fully compliant with astm c805. The rebound depends on the surface hardness of the concrete and is measured by test equipment. Supplied complete with carrying case and carborundum stone, the hammer is suitable for testing concrete with compressive strengths of 10 to 70 nmm2. Concrete test hammer material testing equipment matest. The full power of the hammer is unlocked when used in combination with the schmidt app. A logbook feature summarises all activity, records gps locations and lets you add notes, images and audio comments.
Besides showing the basic settings on the included display unit, the schmidt hammer offers the transmission of the measured data to a standard printer or to a pc. Manual of concrete practicepart 2, 2000, american concrete institute, 38800 3 annual book of astm standards, vol 03. Rebound hammer test, schmidt hammer test, nondestructive. Testing instruments pdf, 640 kb sales flyer schmidt hammers pdf, 314 kb. This fop is based on astm c 805 and has been modified per wsdot standards. I have made some calculations for schmidt hammer test. The hammer measures the rebound of a springloaded mass impacting. Note the rebound hammer method can be used with greater confidence for differentiating between the questionable and acceptable parts of a structure or for relative comparison between two different structures. Astmc805 standard test method for rebound number of. It was devised in 1948 by ernst schmidt, and is therefore known also as schmidt hammer, or sclerometer, test. The schmidt hammer test involves hitting the insitu concrete with a springdriven pin at a defined energy, and then the rebound is measured. Pdf application of rebound hammer method for estimating.
Rebound hammer calculations rebound hammer calculations concreteworld civilenvironmental op 12 nov 12 09. 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. Download standard test method for rebound number of. A new empirical formula for evaluating uniaxial compressive. Pdf the rebound hammer strength test, being a nondestructive test, has its advantages of preserving integrity of sample. Rebound hammer is also known as schmidts hammer or swiss hammer as it is invented by ernst schmidt, a swiss engineer. Types of rebound hammers several hundred thousands of schmidt rebound hammers are in uses worldwide baumann, 2006. The schmidt hammer, developed in the late 1940s as an index apparatus for nondestructive testing of concrete in situ, has been used in rock mechanics practice since the early 1960s, mainly for estimating the uniaxial compressive strength ucs and youngs modulus e t of rock materials. An astm designation number identifies a unique version of an astm standard. By referring to the some conversion tables, the rebound result of the test can be used to determine the. Rebound hammer determination of compressive strength of hardened. A schmidt hammer measures the surface hardness and penetration resistance offered by a section of concrete. Concrete test hammer type nr schmidt concrete impact.
The schmidt hammer in rock material characterization article pdf available in engineering geology 811. Concrete rebound hammer test was first covered by is 311 part 2 1992. Rebound hammer calculations concrete engineering general. Pdf the schmidt hammer provides a quick and inexpensive. Original schmidt live is the latest and most versatile rvalue rebound hammer from the inventors of the schmidt hammer. Standard test method for rebound number of hardened concrete1. Considering its long history and widespread use, the standard methods for. Swiss engineer ernst schmidt is the name of the scientist who first introduced rebound hammer test, and it is also called as schmidt hammer test or swiss hammer test.
Impact results can be heard live in audio on apple ios devices via texttospeech. Revised cpwd specifications, 2002 for cement mortar, cement concrete and rcc works. The hardness measured by the rebound hammer is quite different from the hardness determined in tests on metals which involve indentation. Both windsor probes and schmidt hammer test are basically hardness test but former is costlier than the later. It provides a rapid, nondestructive method of quickly assessing the condition of concrete structures. Active standard astm c805 c805m developed by subcommittee. Is schmidt hammer test a standard test for testing concrete.
The schmidt hammer in rock material characterization. Silver schmidt concrete test hammer nondestructive. Rebound hammers at 18 c 0 f may exhibit rebound numbers e 18. The hammer can be used as a standalone analog hammer, a standalone digital hammer and in combination with a bluetooth printer. Isrm suggested method utr0562 rock classification hammer together with utr0565 nw rock cradle is an easytouse apparatus for measuring the rebound index on rock cores and samples. Follow and observe all instructions that came with the hammer, wear eye protection. Type l schmidt test hammer the type l hammer operates with significant lower impact energy, making this hammer the ideal option for testing thin walled items with a thickness between 2 and 4 50 to 100 mm or for testing small components. This is one of the oldest nondestructive tests and it is still widely used. Impact energy for rebound hammer for different applications. For taking a measurement, the rebound hammer should be held at right angles to them surface of the concrete member. The test can thus be conducted horizontally on vertical surfaces or vertically upwards or downwards on horizontal surfaces. Part 2021986, recommendations for surface hardness testing 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. Perform a few test impacts with the concrete test hammer on this smooth, hard sur face before taking any measurements which you are going to evaluate. Calibration and reliability of the rebound schmidt hammer test estimate the compressive strength of concrete is the rebound hammer test, also known as schmidt hammer test. Astm c805 c805m 18 standard test method for rebound. Proceq invented the original schmidt, the worlds fi rst and now most widely. Schmidt hammer test or rebound hammer test of concrete. Original schmidt rebound test hammer astm d58b14, isrm the quality of concrete is mainly judged by its compressive strength directly affecting the loadbearing capacity and durability of concrete structures. Remove all coatings and adhesives prior to testing. In 1954 proceq sa was founded and has been producing the original schmidt rebound hammers since then, without any. Rebound hammer standards the silverschmidt is fully compliant with en 125042 and en 791. It is superior to rebound hammer test because measurement is made not just at the surface of concrete but in depth. To view the redline modifications, contact the wsdot quality systems manager at 3607095412.
It consists of a springcontrolled mass that slides on a plunger within a tubular housing. The rebound hammer strength test, being a nondestructive test, has its advantages of preserving integrity of sample. Pdf the schmidt hammer in rock material characterization. Astm d5873 14 standard test method for determination of. Digi schmidt the schmidt hammer digi schmidt was developed for the non destructive measurement of the concrete compressive strength and controlling the uniform concrete quality. This device can measure both horizontal and vertical concrete structures. Advanced silverschmidt concrete test hammer st version. Hm75 original schmidt concrete test hammer is the classic rebound hammer known for its accuracy, repeatability, and longevity. Besides, the test is relative simple, economical and versatile compared to. If more than one hammer is to be used, perform tests on 1 this test method is under the jurisdiction of astm committee c09 on concrete and concreteaggregates and is the direct responsibility of subcommittee c09. Hammer verification management tools help you keep your hammer calibrated.
Substrate requirements, compressive and cohesive testing. The silver schmidt stpc concrete test hammer combines a high measurement accuracy with an unmatched repeatability. Much of the published work has focused on improving data gathering procedures and developing new correlations. Part 202, isoidis8045, env 206, igjt 232001 the original schmidt hammer, type n, is designed for nondestructive testing of concrete items 4 100mm or more in thickness, or concrete with a maximum particle size less than or equal to 1. Probe actually fractures the aggregate and compress the material into which it is driven. Standard test method for determination of rock hardness by. To use this test method to estimate strength, it is necessary to establish a relationship between strength and rebound number for a given concrete and given apparatus. The plunger is brought into contact with the concretes surface.
Proceqs schmidt hammer portfolio is the most comprehensive available. The following standards have been applied in silverschmidt for the procedure to determine the rebound number. Astm c805, standard test method for rebound number of hardened concrete, summarizes the procedure as a steel hammer impacts. Before knowing the procedure learn how schidmt hammer. Rebound hammer test procedure for concrete hardness. Considering its long history and widespread use, the standard methods for the schmidt hammer test isrm, 1978a, astm, 2001 might be expected to ensure consistent and reliable values and reproducible correlations for a given rock type.
E 177 practice for use of the terms precision and bias in astm test methods2 3. 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. It is designed for testing concrete within a compressive strength range of 1,450 to 10,152 psi 10 to 70 nmm 2 and impact energy of the test is 1. Schmidt and introduced by proceq at the beginning of the 1950s. Developed in 1948 by a swiss engineer named ernst schmidt, the device measures the hardness of concrete surfaces. Nondestructive testing of concrete by rebound hammer. Standard test method for rebound number of hardened concrete.
Rebound hammer test is conducted around all the points of observation on all accessible faces of the structural element. Proper use of the rebound hammer updated to reflect the. Is schmidt hammer test a standard test for testing. Aug 24, 2016 this is one of the oldest nondestructive tests and it is still widely used. The concrete test hammers are the most widely used portable ndt measuring instruments for a rapid assessment of the condition of a concrete structure. Astm c80585, test for rebound number of hardened concrete. The original schmidt is the classic for the basic testing for concrete and.
These applications include, for examples, the prediction of penetration rates for tunnel boring machines, determination of rock quality for construction purposes, grouping of test specimens, and prediction of hydraulic erodibility of rock. Schmidt hammer, type n supports the following standards. Pdf standard test method for rebound number of hardened. It was invented by ernst schmidt, a swiss engineer. Rebound hammer test schmidts hammer a non destructive test on concrete surface hardness test duration. Around each point of observation, six readings of rebound indices. Utc3045 silver schmidt test hammer proceq is the worlds most advanced rebound hammer fully adapted specifically to the extremely varied concrete testing applications testing on cores and blocks.
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