CIVI 321_ LAB 4

docx

School

McGill University *

*We aren’t endorsed by this school

Course

392

Subject

Mechanical Engineering

Date

Dec 6, 2023

Type

docx

Pages

Uploaded by UltraStingrayPerson94

Lab Report 5 MECHANICAL TESTING OF MASONRY CIVI 321 – X VT April 13 th , 2022 Submitted to: Dr. Ahmed Soliman Concordia University Montreal, QC, Canada

Table of Contents Objective 3 Introduction 3 Procedure 3 1. Preparation of Mortar Cubes and Briquettes 3 2. Preparation of Brick Prisms 3 3. Testing of Mortar Cubes and Dog Bones 4 4. Testing of Brick Prisms 4 Results 4 Discussion & Conclusion 6 Appendix 7 Appendix A: Data Sheet 7 Sample Calculations 9 Bibliography 10 Objective

The objective of this lab experiment consisted of determining if mortar type S is stronger than type N. A comparative analysis of compressive strength of cubes, tensile strength of dog bones and the flexural strength of brick prism was done in order to determine the strongest one. Introduction Testing the material qualities utilised on a building site is crucial since it will decide the strength provided to the structure being built. It is crucial to carry out a batch test of the market- available mortar, much like the batch test of the concrete mixture made from aggregates in the earlier lab experiment. Mortars used purely for aesthetic purposes do not need to be powerful, but they do need to be usable. Other mortars are used for structural binding; thus, they must be able to withstand all of the various loads that are applied to them, including tensile, compressive, and flexural loads. There are several types of mortar available on the market, however type S and N are most frequently used for lab experiments. Type S is utilised for structural load bearing reasons and in exterior applications below grade because it has a stronger resistance to freeze-thaw deterioration, according to numerous tests and actual application in the field. On the other hand, Type N has good workability and is utilised for a wider range of applications, including internal walls and above-grade external walls under moderate load circumstances. Comparing types S and N, type S has a higher compressive strength while type N is medium, which may be explained by the proportion of the components in the mortar mixture. The ASTM C109 will serve to better demonstrate these. Procedure 1. Preparation of Mortar Cubes and Briquettes Lab is divided into two groups, separated into Type N and Type S. Moulds for cubes and dog bones must be properly greased before placing mortar. Mortar mix must be stirred thoroughly till uniform and then can be placed into , nj, n, moulds. The moulds must be filled halfway through the depth and should be tamped properly in two rounds. Once tamped, the remaining of the moulds may be filled and tamped again. 2. Preparation of Brick Prisms The preparation of bricks with a mortar joint will be made. Each type of mortar will include three brick prims with one mortar joint in between. 3. Testing of Mortar Cubes and Dog Bones

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Obtain the specimens that were prepared from the previous lab and wipe each specimen to an SSD condition while removing and loose grains or defects that may come into contact with the testing machine. Place the cube or dog bone sample into the appropriate testing machine and run the test. The compression and tensile strength will be recorded. 4. Testing of Brick Prisms Obtain the brick prisms from the preparation of the previous lab and place the sample in to support frame. Ensure the sample is clamped properly and locked into the proper position. Once the prism is properly clamped into position, a load at a uniform rate can be applied until failure. The failure load will be recorded. Results Cubearea = 50 mm x 50 mm = 2500 mm 2 Table 1: Compressive and Tensile Strength of Mortar Cubes and the Dog Bones Type N Dog Bones 1 2 3 Average Standard Deviation Failure Load (N) 313 240 284 279 36.76 Tensile Strength (MPa) 0.48 0.36 0.42 0.42 0.06 Failure Area (mm^2) 656.61 668.65 671.8 6 665.71 8.04 Type S Dog Bones 1 2 3 Average Standard Deviation Failure Load (N) 855 1051 917 941 100.18 Tensile Strength (MPa) 1.31 1.41 1.40 1.37 0.055 Failure Area (mm^2) 651.14 743.34 653.9 9 682.82 52.43 Type N Cubes 1 2 3 Average Standard Deviation Failure Load (kN) 12.88 13.03 12.95 12.95 0.075 Compressive Strength (MPa) 5.15 5.21 5.18 5.18 0.03 Type S Cubes 1 2 3 Average Standard Deviation

Failure Load (kN) 66.55 65.55 62.88 64.99 1.90 Compressive Strength (MPa) 26.62 26.22 25.15 26.0 0.76 When three cubes are used to represent a test age, the maximum permitted range between specimens is 8.7% of the average; when two cubes are used to represent a test age, the highest allowable range is 7.6%. There is very little variation in standard deviation between samples. The only failure load that differs significantly from the others is that for type S dog bones. Table 2: Flexural Strength of Mortar Joints of Masonry Prisms TYPE S BRICK PRISM S1 S2 S3 Average Standard Deviation Failure Load (N) ø 1144 1375 1259.5 163.34 Flexural Strength (MPa) - 1.18 1.42 1.30 0.17 TYPE N BRICK PRISM N1 N2 N3 Average Standard Deviation Failure Load (N) 133 661 514 436 272.51 Flexural Strength (MPa) 0.14 0.68 0.53 0.45 0.28 Brick prism sample S1 had to be rejected due to the mortar not being applied properly on brick and causing them to sperate before it can be tested. Brick prism N1 had a very low failure load which skewed the results for the average and standard deviation. Brick prism S! has to be rejected due to error during lab. Mortar was not placed properly on the brick before testing. This made it much easier for the bricks to separate from each other. Thus, it was not tested due to this error

Discussion & Conclusion Mortar Prism Type N Type S Average Compressive Strength (MPa) 5.18 26.0 Average Tensile Strength (MPa) 0.42 1.37 Average Flexural Strength (MPa) 0.45 1.30 It is clear from the data that Type S mortar has overall higher compression, tensile, and flexural strengths. Since Type N mortar is used for general purposes while Type S mortar is intended for load bearing applications, this is to be expected. Due of their unique qualities, each mortar has a specific use. Additionally, it should be noted that Type N mortar is more workable than Type S mortar. Both Type N and Type S values have very different ratios. The estimated ratios have a separation of between about 300% and 500%. However, this lab's calculations included several high standard deviations that might not accurately reflect the results. Appendix Appendix A: Data Sheet

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Sample Calculations Compressive Strength (Type N Cube 1) σ = P A 5.15 kN = P ( 50 mm• 50 mm ) P= 12.88 MPa Tensile Strength (Type N Dog Bone 1) Tensile Strength = Failure Load ( N ) Failure Area ( mm 2 ) Tensile Strength = 313 656.1 Tensile Strength = 0.48 MPa Standard Deviation (Type N Dog Bones – Failure Load) Standard Deviation = √ Σ ( x i −´ x ) 2 N − 1 Standard Deviation = √ ( 313 − 279 ) 2 + ( 240 − 279 ) 2 + ( 284 − 279 ) 2 3 − 1 Standard Deviation = 36.76 Flexural Strength (Type S – S2) F g = 6 ( PL + P l L l ) bd 2 − ( P + P l ) bd

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

90 ¿ ¿ ¿ 2 ( 255 ) ¿ F g = 6 (( 1144 )( 370 )+( 0.44 )( 55 )) ¿ F g = 1.18 MPa Bibliography "CIVI 321 Lab Manual, Laboratory No. 1, Aggregates." Concordia University, 2023.