CET 345W Materials Testing Laboratory TESTING AND INSPECTION OF CONSTRUCTION MATERIALS LABORATORY MANUAL, 4th Edition, masters all full reports combined.

Experiments: 1. Verification of Testing Machine........................................................................2 2. Tension Test of Metals ....................................................................... ...

Experiments: 1. Verification of Testing Machine........................................................................2 2. Tension Test of Metals .....................................................................................9 3. Hardness Test of Metals ..................................................................................17 4. Compression and Flexure Test of Concrete ....................................................25 5. Compression and Flexure Test of Wood .........................................................35 6. Torsion Test .....................................................................................................47 7. Impact Test.......................................................................................................53 8. Fatigue Test......................................................................................................61 9. Nondestructive Testing ....................................................................................69 10. Shear Test of Metal Fasteners ...................................................................... 72 Experiment 3. Hardness Test of Metals Objectives - At the end of this experiment the student will be able to: 1. Describe the general principle of operation of the Brinell and Rockwell hardness testers in the analysis section of the report. 2. Determine the Brinell and Rockwell hardness numbers of different metal specimens using standard hardness testers. 3. Recall the uses for hardness numbers and their limitations. 4. Write and submit a laboratory report. Provide a table of experimental results of each specimen tested in the Results section of the Summary for your report. Background Information Several different methods through the years have been devised to rank the relative hardness of different materials. One of the first standards was that of Mohs' scale, frequently used by mineralogists, in which a mineral will scratch other minerals that are lower on the scale but in turn can be scratched by those which are higher on the scale. In this scale diamond had the highest ranking. Hardness is a common property of the material. It is used as an indication of the strength and resistance to scratching and wear. Hardness of metal has been variously defined as: (a) indention hardness, (b) rebound hardness, (c) scratch hardness, (d) wear hardness and (e) the degree of machinability. It should be strongly emphasized that for a particular hardness test, comparisons can only be made of similar type materials. A comparison between the hardness number of steel and plastic is of little value, but as an example of its usefulness hardness comparisons, can be used to evaluate the effectiveness of heat treatment on a given steel. Hardness numbers, though very meaningful for making material selection, cannot be used directly in design or analysis as can tensile strength or modulus of elasticity. Hardness tests are useful in a qualitative sense for controlling uniformity of hardness. An empirical relationship has been established between the hardness number and the tensile strength of certain steels thus allowing the hardness test to be used as a qualitative nondestructive test of tensile strength. It should be pointed out that this comparison has validity only where empirical tests have proven this relationship, therefore generalizations cannot be made. The most commonly used hardness tests in engineering are those involving the relative degree of indentation of the surface of a test material by either a small hardened steel ball or a diamond cone with a rounded point. 19 Two tests frequently used are the Brinell and the Rock