Oil palm empty fruit bunch ash stabilized laterite as a fill material for low-volume pavement

A reddish-brown laterite was treated with up to 14 % oil palm empty fruit bunch ash (EFBA) by dry weight of soil and compacted with the British Standard light, BSL (or Standard Proctor) compactive effort. Index, compaction, strength and durability tests as well as microanalysis of the natural and stabilized specimens were carried out. The index, compaction characteristics (maximum dry density, MDD and optimum moisture content, OMC) and strength properties (California bearing ratio, CBR and unconfined compressive strength, UCS) were improved with higher EFBA treatment. Peak un-soaked and soaked CBR values of 70.0 and 45.0 %, as well as peak UCS strengths of 253.0, 462.0 and 577 kN/m2 at 7, 14 and 28 days curing were recorded at 8 % EFBA content. Based on the CBR specification specified in the Nigerian General Specifications, the laterite optimally treated with 8 % EFBA compacted with the BSL compactive effort can be used as a fill material in the construction of low-volume traffic pavement. The benefit of the EFBA application is primarily the reduction of the adverse environmental impact of the oil palm empty fruit bunch waste. Keywords: California bearing ratio, durability, laterite, oil palm empty fruit bunch ash, microanalysis, stabilization

Influence of fly ash, lime Sludge and Polypropylene fibre on Compaction and Strength Properties of Subgrade

The development of population, quick urbanization and more development of structures and buildings has brought about the decrease of good quality land. To improve the accessibility of good quality land, strength and compaction properties of land should be improved. The fundamental goal of this examination is to explore the utilization of fly ash, lime sludge and polypropylene fiber in Geotech highway application and to assess their impact on quality and compaction of soil, utilized for subgrade. The soil samples were gathered from the zones of Chandigarh where clayey soil is present in abundance. The laboratory testing led to decide the strength and compactive effort of the clay soil. This investigation includes three principle tests. The primary test is standard proctor test. The subsequent test is California bearing ratio and the third test is the direct shear test. Proctor test gives the compactive effort of the soil and CBR gives the subgrade strength. The outcomes acquired are thought about for the examples and inferences are drawn towards the unstability and effectiveness of admixture support at different percentages, as replacement for high quality subgrade and cost-effective approach.

Effect of Compactive Efforts on Strength of Laterites Stabilized with Sawdust Ash

This study investigates the effects of different compactive efforts on the strength of laterites stabilized with sawdust ash (SDA). Laterites in the categories of A-7-5 and A-7-6 were considered because they are not suitable in the natural states as subgrade materials. The geotechnical properties of the laterites in their natural states were determined. The sawdust was burnt and sieved through 600micron. The sawdust ash (at 2%, 4%, 6%, 8% and 10%) was added to the laterites and the atterberg limits were determined, while the California bearing ratio and Unconfined compression test were determined using three compactive efforts (596, 1192 and 2682KN-m/m3).It was generally observed that the maximum dry densities of the natural and stabilised laterites increase with increase in the compactive efforts, while the optimum moisture contents reduce. The plasticity indices of the laterites increased with the addition of SDA. The optimum values of the MDDs (2006 and 1878 kg/m3) were observed at 4% and 6% SDA of 2682 kN-m/m3 compactive effort for samples A and B, respectively. The soaked and unsoaked CBR values of the soils at natural state are 4.89 and 16.33%, and 3.4 and 5.62% for samples A and B, respectively. The results indicate that the higher the compactive efforts, the higher the CBR values of the two samples. Increase in SDA contents of soil samples A and B showed a non-predictable trend on their CBR values. The Unconfined Compressive Strength values at natural and treated states fell below the requirements. Generally, it was found that the use of sawdust ash alone as stabilizer was not effective. Therefore, it was concluded that future studies should consider the use of the sawdust ash in combination with cement or lime.

Geotechnical Characterization of Sub-Soil within Ladoke Akintola University of Technology, Ogbomoso-Nigeria

This study investigates geotechnical characterizations of sub-soil within LAUTECH community as well as the relevant engineering characteristics were evaluated to enable appropriate foundation design. Nine (9) soil samples were obtained at 1.0, 2.0 and 3.0m using boring methods from three locations: LAUTECH Security Unit,(LSU:N8°5.977; E4 10.112), LAUTECH Chapel, (LC:N8° 07.756; E004’ 12.981), and LAUTECH Software Building, (LSB: N8° 09.986; E4’15.781′). The samples were subjected to visual examination and subsequently geotechnical tests in accordance to British Standards BS 1377, (2000). The tests were Specific Gravity (SG), Particle Size Distribution Analyses (PSDA), Liquid Limit (LL), Plastic Limit (PL), and Compaction test using British Standard Light (BSL) compactive effort, California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS). The samples from all the locations varied from light brown sand to reddish gravel. The SG values for LSU, LSB and LC were (2.66, 2.63, 2.37); (2.68, 2.59, 2.60); (2.48, 2.67, 2.43), respectively, while the grain size varied from fine to coarse. The LL values obtained for LSU, LSB and LC were 38.0, 37.0, 44.0% and 34.0, 32.0, 35.0%, while the corresponding PL values were 21.0, 26.0, 28.0%, and 24.0, 20.0, 21.0%, respectively. The maximum dry density values were (1.94, 1.66, 1.38; 2.38, 2.23, 1.93; 2.02, 2.12, 1.77) g/cm’and OMC values were (13.5, 17.2, 19.2; 11.6, 16.4, 13.8; 12.1, 9.4, 14.0) %, respectively. The ranges of CBR values for the soaked and un-soaked samples for LSU, LSB and LC were 26.0 – 38.0; 36 – 52; 26.0 – 59.0%, and 61 – 74; 71 – 85; 56 – 70%, respectively. The UCS values for the disturbed and undisturbed samples were (363 ~ 865; 497 ~ 694; 202 ~ 596) kN/w and (396 ~ 831; 427 ~ 726; 236 – 732) KNAm’. The samples obtained from LSU and LC were classified as A-2, while LSB sample was classified as A-4 and A-6. The samples obtained at (1m) depths within LAUTECH Community are suitable as sub-grade materials. Hence, stabilization is recommended at further depths prior to their applications for engineering purposes.