Based on the rebound hammer number obtained for a concrete surface, compressive strength can be obtained from the empirical relationship developed for the rebound hammer. Stl provides the non destructive testing facilities to its clients and has following ndt testing facilities. The rebound hammer test is not intended as a substitute for standard compression test, but as a method for determining the uniformity of concrete in the structure and comparing one concrete with another. Rebound hammer test is a nondestructive ndt test of concrete and simple concrete test which is used to test the compressive strength of concrete without any damage. The non destructive test methods ndt have been used to evaluate the concrete strength in many countries, and experimental studies have investigated which method is more reliable and practical. However, the results of the test on concrete are affected by various factors such. Mar 30, 2018 the present investigation is mainly focused on predicting compressive strength of geopolymer concrete gpc using non destructive testing ndt techniques viz. Essay about nondestructive testing of concrete 2567 words. Impact echo ie, is a non destructive test method that uses compression waves to determine the thickness of concrete slabs with minimal interference from reinforcement. Sep 19, 2014 rebound hammer test rebound hammer test is done to find out the compressive strength of concrete by using rebound hammer as per is. Rebound tests the rebound hammer is a surface hardness tester for which an empirical correlation has been established between strength and rebound number. May 24, 2018 i love what you mentioned about combined methods and how they involving using ndt methods to predict concrete strength.
Hence, the main purpose of this study is to propose an efficient approach to predict the compressive strength of concrete using non destructive tests upv and rn. The schmidt rebound hammer is principally a surface hardness tester with an apparent theoretical relationship between the strength of concrete. Ndt powerful technique for evaluating exiting concrete structures with regard to their strength and durability apart from assessment and control of quality of hardened concrete without or partial damage to the. Estimate concrete strength using rebound hammer fprimec. Advancing concrete strength prediction using nondestructive. The rebound hammer developed by schmidt provides an inexpensive and quick method for nondestructive testing of concrete. Testing concrete in structures nondestructive testing determination of rebound number. Pdf application of rebound hammer method for estimating. Standard testing laboratories is offering non destructive testing ndt services in delhi ncr, india. The standard rebound hammer provides a simple, easy and inexpensive method to estimate concrete strength properties. Windsor probe this is most effective non destructive test, with adherents and practitioners around the globe. The concrete strength is estimated using curves that correlate the ndt measurements with the compressive strength of concrete established by a. Jul 09, 2019 the rebound hammer developed by schmidt provides an inexpensive and quick method for nondestructive testing of concrete.
Comparison of nondestructive test methods for concrete. The test is essentially nondestructive, since concrete and structural members can be tested in situ, with only minor patching of holes on exposed faces. Non destructive testing is convenient because you receive accurate data without letting anything go to waste. Application of rebound hammer method for estimating. Jan 19, 2019 tests on concrete non destructive testing on concrete by rebound hammer method. Correlation between schmidt hammer and destructive. Correlation between destructive compressive testing dt and. Two very important non destructive testing methods have been used for many years to estimate the compressive strength of concrete. These are schmidt rebound hammer and ultra sonic pulse velocity upv. Review of the rebound hammer method estimating concrete. Rebound hammer test is a non destructive testing method of concrete which provide a convenient and rapid indication of the compressive strength of the concrete. The compressive strength can be evaluated directly from the graph provided on the body of the hammer. Application of rebound hammer method for estimating compressive strength of bricks. Rebound hammer a handy non destructive testing instrument should be cheap, easy to operate and should have reproducibility for, fairly accurate results.
Standard testing lab stl is the best ndt testing lab which provides testing by the rebound hammer, ultrasonic pulse velocity test and radiography. Rebound hammer test is done in order to find out the the compressive strength of the concrete by using rebound hammer as per is. The only known instrument to make use of the rebound principle for concrete testing is the schmidt hammer, which weighs about 4 lb 1. Ndt is a method for the testing of existing concrete structures so as to determine the durability and strength. A handy non destructive testing instrument should be cheap, easy to operate and should have reproducibility for, fairly accurate results.
Ultrasonic pulse velocity upv upv method is a wellknown non destructive testing method that conducted by the velocity of compression stress waves pwaves. Rebound hammer test graph describes the correlation between the strength of concrete and rebound number. In 1948, a swiss engineer, ernst schmidt developed a test hammer for measuring the hardness of concrete by the rebound principle. Cost in both time, money and structural and aesthetic integrity of the structure hs lead to the development of non destructive tests. Non destructive testing ndt is mainly concerned with the evaluation of flaws in materials which are in the form of cracks and which might lead to loss of strength in a concrete structure samson et al. Use of the schmidt rebound hammer for non destructive concrete structure testing in field. Non destructive testing of concrete methodsoftest part 2 rebound hammer 1 scope this standard covers the object, principle, apparatus and procedure of rebound hammer test method. Comparison of nondestructive and destructive testing on.
Tests on concrete non destructive testing on concrete by rebound hammer method. Parameters that influence the results of non destructive test. Rebound hammer see other formats disclosure to promote the right to information whereas the parliament of india has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote. The ndt techniques were performed to compare the accuracy between the srh, upv and combined method in estimating the compressive strength of gpc. Another attempt was made by the same researcher to assess compressive strength of calcium silicate bricks using a combination of the rebound hammer method and ultrasonic pulse method sonreb in which he stated that the combined non destructive sonreb method was proved applicable for determination of compressive strength of calcium silicate. Rebound hammer test is a nondestructive testing method of concrete which provide a convenient and rapid indication of the compressive strength of the concrete. The destructive testing dt method is carried out by crushing the cast specimen to failure while non destructive testing ndt is carried out without destroying the concrete specimen. In this study, a relationship is determined and correlated between non destructive testing ndt named as schmidt rebound hammer test and concrete destructive compression test. Note in view of the limitations of each method of non destructive testing of concrete, it is essen. How to estimate strength of concrete using ndt methods. One of these methods is a classic ndt method based on the surface hardness testing of concrete which became. When using the rebound hammer, the limitations of the test method should be recognized and taken into account.
With non destructive testing ndt devices the measurements can be performed directly on the structural concrete and the strength of concrete can be estimated from the measured results with limited reliability. Predicting compressive strength of geopolymer concrete using. Schmidt hammer test or rebound hammer test of concrete. Guidebook on nondestructive testing of concrete structures. The rebound hammer is a surface hardness tester for which an empirical correlation has been established between strength and rebound number. Because of the above limitations, the combined use of these two methods is made in another way. Inspite of its popularity, this testing has not been standardized in any.
In the non destructive method of testing, without loading the specimen to failure i. Moreover, the best part of rebound hammer test is concrete can be tested in real time at the site instead of going to the lab without any damage. Comparison of destructive and nondestructive testing of. The electrical properties of the concrete, allow us to estimate its moisture content, density, thickness and its cement content. In addition, influence of test conditions and some general guidance on the interpretation of test results are also given. Testing the strength of concrete without destructing or breaking it after hardening is a complex task. Nondestructive testing of concrete methods of test lecture no.
Popular non destructive testing of concrete structure. Concrete compressive strength prediction using non. Non destructive testing lab ndt testing lab in delhi. Ndt powerful technique for evaluating exiting concrete structures with regard to their strength and durability apart from assessment and control of quality of hardened concrete without or partial damage to the concrete. Non destructive testing of concrete methods of test lecture no. Tests on concrete non destructive testing on concrete by. Based on above, various nondestructive methods of testing concrete have been developed. Nondestructive testing of concrete methods of test. Method of non destructive testing of concretmethods of test, part 2.
As we already discussed the compressive strength of concrete by concrete cube test which is a destructive test worked out in the lab. The rebound hammer is also called as schmidt hammer that consist of a spring controlled mass that slides on a plunger within a tubular housing. Nondestructive testing of concrete ndt on concrete non destructive test is a method of testing existing concrete structures to assess the strength and durability of concrete structure. Nondestructive testing of concrete by rebound hammer. Rebound hammer test on concrete principle, procedure. Rebound hammer testing, radiography non destructive testing. The test is essentially non destructive, since concrete and structural members can be tested in situ, with only minor patching of holes on exposed faces. Non destructive testing is a form of testing to be carried out on various construction members and materials. In all these methods of tests, due to simplicity, rebound hammer test based on surface hardness becomes most popular in the world for non destructive testing of insitu concrete. The rebound of an elastic mass depends on the hardness of the surface against which its mass strikes.1296 1562 933 1181 236 1149 756 1497 1277 76 713 1237 1057 1597 416 570 684 24 999 274 480 679 1328 1023 1229 851 1599 1293 414 518 1258 466 15 563 372 803 189 348 1083 59 1002 141 942 825 795