Soil Mechanics Lab Report, Lab Reports of Soil Mechanics and Foundations

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EGC 2173 Soil Mechanics Falling Head Test Lab Report Name Student ID Section Lim Jin Juen I19017131 8G1Ethan Low I19018100 Naghib Swaleh I19018297 Lecturer: Nurul Ain Ibrahim Lab Report Rubric Criteria Description Weightage Marks awarded Objectives / Introduction / Theory Good coverage of the theories on the subject and demonstrate the ability to relate its significance to the experiment. 0 5: Theories are copied from the lab manual/no theories 6 — 10: Small amount of research is completed 11-15: Comprehensive research relevant to the topic is done Methodology / Procedures The ability to report the procedures / methods in completing the experiment. 0-5: Procedures are copied from lab manual 6-8: Limited elaboration of the procedures of the experiment 9-10: Complete description of the procedures with figures or other form of illustrations 10 Results / calculations Results to be presented professionally and relevant calculations are shown. Graphs are drawn professionally where necessary. O- 5: Minimum presentation of results 6-10.' Basic results are shown with necessary calculations. 11-15: Further analyses of the results using graphs, tables, etc. Discussions Demonstrate the ability of analysing the results in an independent and critical way. In-depth discussion is presented on the variance of the results with theory, or the effect of the changing of any parameters to 30 Table of Contents Page 1) Introduction 5 2) Objective 6 3) Apparatus and procedure 8 4) Results and Calculation 9 5) Discussion 12 6) Conclusion 14 7) Reference 16 8) Appendix 17 Objective The purpose of this investigation was to examine available methods to measure permeability and to determine the general magnitude of permeability for mixtures being used by VDOT, with an emphasis on Super pave mixtures. Tests were also performed on specimens prepared in the laboratory and matching pavement cores to determine whether tests performed on laboratory specimens indicated field permeability. Introduction The fact that the durability of asphalt concrete is compromised when a pavement has a high air void content has been recognized for many years. Not only do void spaces allow air to enter and oxidize the asphalt cement, but water can also enter and cause freeze-thaw and stripping damage. Brown indicated that to be waterproof, asphalt pavement must have no more than 8 percent voids for fine mixtures and 6 percent voids for coarse mixtures. In 1996, a field study of Virginia pavements found that pavement voids were higher than desirable and visible stripping damage was significant. In addition, it is not uncommon to see damp spots remaining on the surface of Virginia’s asphalt pavements several days after a rain. The Virginia Department of Transportation (VDOT) wanted to know if high voids, stripping, and damp spots indicate permeable pavements and, if so, how permeable the pavements are. There is also concern about the permeability of super pave mixtures. A study by the Florida Department of Transportation (FDOT) in 1996-97 indicated that their Super pave mixtures had high permeability at void levels that were 9) Measuring cylinders of 100 ml, 500 ml and 1000 ml. 10) Scoop. 11) Flat ended tamping rod. 12) Thermometer. 13) Stop clock. 14) Balance readable to 1 g Procedure: 1) The base plate was assembled, with perforated base, to the permeameter cell body. 2) The graded filter material was placed in the bottom of the cell to a depth of about 50 mm. The surface was levelled and a wire gauze (or porous disc) was placed on top. 3) The soil was placed in the permeameter in at least 4 layers, each of which was of a thickness about equal to half the diameter. 4) Tamp each layer with a controlled number of standard blows with the tamping rod. The surface of each layer was levelled before adding the next. 5) The upper wire gauze (or porous disc) was on top of the sample. 6) The graded filter material was placed on top of the disc to a depth of minimum 50 mm. 7) The piston was released in the top plate and withdrew it to its fullest extent. 8) The top plate was fitted to the permeameter cell and tightened down in position. 9) The piston was lowered carefully and bed the perforated plate on to the filter material. The piston was held down firmly and tightened the locking collar in this position. 10) The mean length of the test sample, L (in cm) to 1 mm, was determined by measuring at three locations around the perimeter. 11) The soil left over was dried and weighed it to 1 g (m2), so that the dry mass of the test sample could be obtained by difference. 12) The control valve was connected on the base of the permeameter to the water supply. The top connection was open and the air bleed to atmosphere, and closed the connection to the manometer tubes. (1.0) and allowed the water levels in the manometer tubes to become stable before starting test measurements. 20) A measuring cylinder of suitable capacity was placed under the outlet from the discharge reservoir and simultaneously started the timer. 21) The quantity of water collected in the cylinder was measured during a given time interval. Alternatively record the time required to fill the cylinder up to a given volume. 22) The water levels in the manometer tubes was recorded. 23) The temperature of the water in the discharge reservoir was recorded. 24) Steps 19 to 23 were repeated four more times, or until consistent readings were obtained. Calculation Diameter = 10.5 cm Height = 12 cm Burette area (α) = ) = 0.7854 cm^2 specimen diameter (D) = 10.5 cm specimen area (A) = 126 cm^2 specimen length (L) = 12 cm Sample 1 time (min) initial head final head ho/hi hydraulic conductivity, K 600 898 824 1.089805825 1.07213E-05 600 824 762 1.081364829 9.75192E-06 600 762 694 1.097982709 1.16532E-05 600 694 624 1.112179487 1.32548E-05 600 624 590 1.057627119 6.9848E-06 600 590 544 1.084558824 1.01196E-05 600 544 496 1.096774194 1.15159E-05 600 496 464 1.068965517 8.31419E-06 600 464 420 1.104761905 1.24205E-05 K avg = 1.07213E-05 Sample 2 time (min) initial head final head ho/hi hydraulic conductivity, K 600 860 758 1.134564644 1.5739E-05 600 758 650 1.166153846 1.91626E-05 600 650 592 1.097972973 1.16521E-05 600 592 552 1.072463768 8.7215E-06 600 552 498 1.108433735 1.28342E-05 K avg = 1.23778E-05 Using sample2, 3rd row: ho/hi = initial head/ final head = 860/758 = 1.134 Permeability, K = = 1.5739E-05 cm/min ( 0.7854 ∗12 126 ∗600 ) ∗ln1.134564644