# Comparison of Field and Laboratory Tests for Soil Suitability Assessment in Raw Earth Construction
## 3 Results and Discussions
### Field Test Results and Analysis
The dropped ball remained intact for all the tested soils but with some cracks for soils 4 and 6. To improve future trials, several adjustments to the protocol and the evaluation of results can be considered. First, to ensure a fair comparison, it would be beneficial to measure each soil's water content and verify that it aligns with the plasticity limits of the soil. Additionally, standardizing the size of the test ball could enhance consistency; for example, using a ball with a diameter of 5 cm. The test result could then be based on measuring how much the ball spreads upon impact with the ground. The cigar test shows lengths of around 37 cm for soil 1, 26.5 for soil 3, 4.8 for soil 4, 6.9 for soil 5, 7.06 for soil 6, 5.9 for soil 7, 15.7 for soil 8, 3.6 for soil 9, and 7 for soil 10 indicating a wide variety of value for this test. Soils 1, 3, and 8, with a high clay-sized particle content, have values greater than 15 cm and, therefore, can be considered very cohesive. Soils 5, 6, and 10 can be considered moderately cohesive, and soils 4, 7, and 9 are weakly cohesive. The jar test results, which indicate the number of visible layers in the sedimentation process, provide important insights into the particle size distribution and uniformity of the soils. In the tested soils, the number of visible layers varied from one to three layers, suggesting clear particle size segregation was based on settling velocities. Soils showing only one visible layer (soil 1, 3, 5, 6, 7, 8, 9, and 10) indicate a more uniform particle size distribution. In contrast, soil 4 demonstrates a more distinct particle size segregation, indicating less uniformity in the particle size distribution. Well-graded soils typically achieve better compaction and potentially better mechanical performance due to optimal particle packing. A uniform particle size distribution might require modification through mixing with other soil fractions to achieve the desired gradation for construction purposes. The smell test provides an initial screening tool for organic content. When performed on the collected soils, a distinct humus odor was detected in soils 2, 11, 38, and 39, suggesting significant OM content. These soils were consequently excluded from further testing as high organic content can adversely affect construction properties through reduced mechanical resistance, increased shrinkage potential, and higher porosity [21]. However, it is important to note that while the smell test provides a quick preliminary assessment, it should be validated with quantitative laboratory testing, such as the loss on ignition, as the relationship between odor intensity and actual organic content is not always linear [45]. The pellet test shows no shrinkage for soils 1 and 6, little shrinkage for soils 3, 4, 5, and 7, a shrinkage of 4% for soil 8, a shrinkage of 11% for soil 9, and a shrinkage of 18% for soil 10. [PERSON] et al. [9] showed similar drying kinetics for in situ and climatic chamber simulation studies in the laboratory. Furthermore, good resistance was obtained for soils 1, 3, 8, and 9, medium resistance for soils 5, 7, and 10, and low resistance for soils 4 and 6. The field tests were easily carried out and provided a qualitative evaluation of soil characteristics. The results reveal variability in the properties of the tested soils. A detailed examination of the field test results revealed several significant correlations between different tests. The ring test, which evaluates clay-sized particle content and soil plasticity, shows a strong correlation with the ribbon test results--soils scoring high on the ring test (5, such as soils numbers 1, 3, 8) generally performed well in the ribbon test (5), while those with low ring test scores (0, like soils numbers 4, 6) similarly showed poor ribbon test performance (0-1). This correlation is logical as both tests primarily assess clay-sized particle content and soil plasticity. The cigar test results appear to be indicative of overall soil performance, showing strong correlations with other tests.