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Percent Passing Hydrometer Analysis Results: Sample #15: Grain Size Distribution Curve of Fine Fraction of Sample 100% 80% 60% 40% 20% 0% 0.001 0.002 0.010 0.100 Figure 4.11: Sample #15 Grain Size Distribution Curve Sample #15: Hydrometer Results % Silt in Fine Fraction of Sample 70% % Clay in Fine Fraction of Sample 30% Table 4.9 Based on the results from the wet sieve analysis and Atterberg limit tests, both soil Samples #11 & #15 can be classified as CL (lean clay with low plasticity) using the USCS method adapted from ASTM D2487 (see Appendix 8.1 for applicable charts). Samples #11 & #15 were found to have plasticity indices of 15 and 13, respectively. Figure 3.7 suggests that these samples range from slightly plastic to medium plastic indicating a low to medium clay content. Particle Size (mm) The Hydrometer test results show that the fine grained portion (amount of soil to pass a #200 sieve) of Samples #11 & #15 contain 34% and 30% of clay, respectively. It is noteworthy that this test only measures the silt/clay ratio for the fine grained portion of 44
the sample and not the entire soil sample itself. The cohesive nature of clay supplies the binding forces between particles in the soil mix matrix. While a higher percentage of clay would imply more cohesion and therefore a stronger SCEB, the silt portion also contributes to the range of particle sizes in the soil mix. The silt particles may increase the overall density of the SCEB, enhancing its performance. This topic needs to be researched further, before a definitive conclusion can be made regarding an ideal silt/clay ratio for a suitable soil in SCEB production. Percent Passing 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Grain Size Distribution Curve: "Sand 1 of 4" Percent Finer by Weight Silts & Clays Fine Sand Medium Sand Coarse Sand Gravel 0.01 0.1 1 10 Grain Size (mm) Figure 4.12: “Sand 1 of 4” Grain Size Distribution Curve 4.2.2.2. Preparation of Soil Mixtures To illustrate the effects of varying the soil mix ratio on unconfined compressive strength, model-size (2.5” x 3.5” x 1”) SCEBs were produced. UMU soil Sample #11 was used to produce mini-blocks in accordance with the procedure described in Section 3.6. Four soil mixes with clayey soil to sand ratios varying from 1:2.5 to 1:4, were used 45
Page 1 and 2: A Proposed Best Practice Method of
Page 3 and 4: Krosnowski, Adam Davis (M.S., Depar
Page 5 and 6: Table of Contents 1. Introduction .
Page 7 and 8: Table of Figures Figure 2.1: World
Page 9 and 10: 1. Introduction The demand for sust
Page 11 and 12: soils must be defined to standardiz
Page 13 and 14: move more towards sustainable “gr
Page 15 and 16: 2.1. SCEB Technology Advantages The
Page 17 and 18: latent heat of vaporization. The ef
Page 19 and 20: sedimentation (jar) test, ball drop
Page 21 and 22: opportunities for water to alter th
Page 23 and 24: 3.2. Testing Methodology Flow Chart
Page 25 and 26: transported sealed in airtight five
Page 27 and 28: Figure 3.2: Gilson Testing Screen M
Page 29 and 30: infer the clay content. Figure 3.7
Page 31 and 32: potential for minimizing costs. Det
Page 33 and 34: calculate bulk unit weights of the
Page 35 and 36: 3.9. Modulus of Rupture: Three-Poin
Page 37 and 38: Figure 3.16: SCEBs soaking in water
Page 39 and 40: samples from the Dead Man‟s Curve
Page 41 and 42: previous experience, visual inspect
Page 43 and 44: one week intervals during the initi
Page 45 and 46: UCS [psi] UCS [psi] 1000 800 600 40
Page 47 and 48: UCS [psi] UCS [psi] 1000 800 600 40
Page 49 and 50: Lower Limit: 1 part cement, 1 part
Page 51: Percent Passing Soil #15: Hydromete
Page 55 and 56: Large blocks were produced from two
Page 57 and 58: The large blocks produced were kept
Page 59 and 60: decreased by 23-25% over the course
Page 61 and 62: Figure 4.23: UMU Mini-Blocks; Five
Page 63 and 64: Average UCS [psi] 2000 1600 1200 UM
Page 65 and 66: Clayey soil is often mined and tran
Page 67 and 68: Figure 5.1: Full Block in 3-Point B
Page 69 and 70: nature will increase the level of c
Page 71 and 72: this point of testing. The testing
Page 73 and 74: Average Large Block UCS [psi] 800 7
Page 75 and 76: Figure 5.13: Aspect Ratio Test, Fiv
Page 77 and 78: Figure 5.17: Aspect Ratio Test, One
Page 79 and 80: E [ksi] 35 30 25 20 15 10 y = 23.85
Page 81 and 82: The equation of the trend-line was
Page 83 and 84: of optimizing a soil mix design. Of
Page 85 and 86: plasticity. They also do not offer
Page 87 and 88: the SCEB strongly influence its com
Page 89 and 90: specimens will be tested for compre
Page 91 and 92: P f Pf [ psi] 2 A force at fail
Page 93 and 94: Coduto, D. P. 1999. Geotechnical En
Page 96 and 97: 8.2. Crow Tribe Case Study Test Dat
Page 98 and 99: 8.2.2. Schmidt Hammer Test Data R V
Page 100 and 101: UMU Sample #15 1:3 (6 x 12 x 3 5/8)

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