Papers by Keyword: Compaction

Abstract: Black cotton soil (BCS) which is an example of expansive soil has present substantial obstacles to engineering projects. The seasonal volumetric changes in this black cotton soil led to swelling and shrinkage, thereby compromising its geotechnical properties and making it unsuitable for engineering project. In this study, black cotton sol was stabilized using various ratios of xl-Terrasoil and xl-Bond to enhance the soil's properties.. Xl-Terrasoil and xl-Bond are chemical product with stabilizing properties and commercially available. Samples of BCS were examined by varying percentages of xl-Terrasoil and xl-Bond to 1, 1.5 2, 5, 6 and 7%, of xl-Terrasoil with 2, 3, 4,10, 12 and 14% of xl-Bond. A variety of geotechnical tests, including the Atterberg limit, compaction, and California bearing ratio tests, were performed to evaluate the enhancement of soil characteristics. The results from the Atterberg limit test indicated a decrease in the liquid limit (LL) and an increase in the plastic limit (PL) when compared to the high values recorded in the control sample. The mix ratio of 7% xl-Terrasoil and 14% xl-Bond produced the highest maximum dry density (MDD) alongside the lowest optimum moisture content (OMC). For the California bearing ratio (CBR), the highest value was observed in the combination of 7% xl-Terrasoil and 14% xl-Bond, which demonstrated a more effective stabilizer mixture in this analysis. Conclusively, the properties of BCS have improved with certain proportions of these admixtures thereby making the soil more stable. Further investigation on the long term of these admixtures on environmental conditions is suggested.

Abstract: Limited land with good soil quality results in infrastructure being built in areas with unfavorable soil characteristics. development. Soil with unfavorable characteristics one of which is swamp land. Swamp soil needs to be stabilized if we want to build buildings on that land, the stabilizing material used can be silica waste or other binding materials. In this test, steel slag, fly ash, and glass bottle powder were used as the main stabilizers, with a fixed percentage of 20% steel slag and 20% fly ash, and glass bottle powder as an independent variable with a percentage of 0%. 5%, 10%, and 15%, and with the aging time of 0, 3, and 7 days. Testing the characteristics of Situ Rawa Arum, Jl. Kp. Tegal Wangi No. 62, Kec. Gerogol City of Cilegon Banten has poor soil carrying capacity with a CBR value of 1%. After stabilization using steel slag, fly ash, and glass bottle powder there was a significant change. The most optimum change in soil carrying capacity occurred in a mixture of 5% glass bottle powder + 20% steel slag + 20% fly ash with a CBR value of 31%.

Abstract: This paper presents the regression model for predicting the maximum dry density (MDD) and optimum moisture content (OMC) for sedimentary residual soil mixed with bentonite. The empirical models were developed in accordance with the statistical validity steps and conditions. The laboratories were conducted to determine the physical properties of mixed samples with bentonite such as Atterberg limit and particle size distribution. Meanwhile the compaction testing was performed on the mixed soil samples with bentonite to determine the MDD and OMC values at different compaction energies. The data obtained from laboratories and secondary data were used to develop an empirical model. The results showed there is significant relationship between the particle size, compaction energy and bentonite content to the OMC. Meanwhile there is a relationship between the OMC, bentonite content and compaction energy to the MDD. Reasonably good regression coefficients are obtained in case of both model which R² = 82% for MDD model and R² = 72% for OMC model. Meanwhile the determination coefficient and mean square error (MSE) for validated model between predicted model and empirical model were given R² = 89.5% with MSE = 0.065% for MDD model and R² = 79.5% with MSE = 5.9% for OMC model. Therefore, the models developed present a good predicting for MDD and OMC values.

Abstract: Powder metallurgy has become a compatible alternative method in term of manufacturing complex component, such as frangible bullet. A bullet with frangible properties can be manufactured by using copper-based metal matrix composite with tin as the reinforce. During compaction process, the applied load and dwelling time are considered as substantial factor which affect the final product. Therefore, the aim of the present work study is to observe the pressure and the holding time during the compacting process (dwelling time) which has an impact on the mechanical properties of the Cu-Sn composite product. The green component or pressed product is tested with various compaction pressure variables, namely 500, 600, and 700 MPa with 0, 5, 15, 30, 45 minutes dwelling time, respectively. The sintering process is performed at 260°C for 30 minutes in the horizontal furnace. The result shows that the surface contact area was increased along with the compaction load upsurge which led to low porosity green compact. The 700 MPa compaction pressure with 15 minutes dwelling time has the optimum density, hardness, and compressive strength, which had 8,454 gr/cm³, 87 HRF and 349.74 MPa in value. The compacting product has been tested on Scanning Electron Microscope (SEM) and showed that 700 MPa compaction pressure had the best powder densification process.

Abstract: The article describes the behavior of a fresh concrete exposed to the effects of vibration. The individually deposited layers of concrete mix are able to migrate in the vertical and horizontal direction in the specimen or structure. This phenomenon is simulated using successively deposited layers of colored concrete of defined height. The specimens were exposed to vibrations of variable frequency and amplitude. The degree of interconnection between the layers is determined by using regular sections across the specimens to observe the differences in the movement and interconnection of the layers for different consistencies of the concrete mix. The results summarized in this paper present new results of continuous research aimed at a more detailed description of the vibration behaviour of fresh concrete, as this phenomenon is relatively marginally addressed in the current standards.

Abstract: Different fines of rice husk ash (RHA) are typically used as a binder for soil stabilization. This study aims to assess the performance of RHA fines as a binder with lime in the improvement of plasticity and compaction characteristics of stabilized soil. Consistency limits, particle sieve analysis, and compaction tests were conducted on the natural lateritic soil, while consistency limits and compaction tests were conducted on the stabilized lateritic soil. The tests conformed to BS 1377 (1990). The chemical compositions of the RHA were assessed. Lateritic soil samples were mixed with lime in the proportions of 2, 4, 6, 8, and 10% by weight of dry soil. Plasticity Index (PI) was used as the determinant of optimum performance of lime-stabilized lateritic soil and this was obtained at 8% of lime addition. Thereafter, binder ratios (Lime: RHA) of 0:8, 2:6, 4:4, 6:2, and 8:0 were employed in the blending of the lateritic soil. The Plasticity Index (PI) of the stabilized soil were generally lowered to 7.82%, 21.36%, 18.97%, 19.71%, 15.03% when stabilized with BR2:6₇₅μm, BR4:4₇₅μm, BR6:2₇₅μm, BR2:6₃₀₀μm and BR6:2₃₀₀μm respectively. All binder ratios containing both lime and RHA size of 75 μm reduced the PI. Also, the effect of all binder ratios containing both lime and all RHA sizes showed increment in the Maximum Dry Density (MDD). Similarly, soil stabilized with BR2:6₁₅₀μm, BR4:4₇₅μm, BR4:4₁₅₀μm, BR4:4₃₀₀μm, BR6:2₁₅₀μm and BR6:2₃₀₀μm offered a lowered OMC. 75μm RHA and BR4:4₇₅μm had the potential to improve Lime-RHA stabilized lateritic soil mixture especially for road application.

Abstract: The article discusses a powdered material - carbidostal. Comparative characteristics of carbidostals, tool steels are given and hard alloys. Methods of producing and producing carbidostals are considered. Conditions for free separation of residues of impregnating material from the surface of the article are established. The reasons of volumetric change of amount of carbides and binding by height of impregnated press are studied.

Abstract: Dune sands are poorly graded collapsible soils lacking fines. This experimental study explored the possibility of sustainable invigoration of fine waste materials in dune sand to improve the geotechnical properties. The fine wastes used in this study are reservoir sediments and marble waste powder. The fine waste powder was mixed with dune sand at different percentages (5, 10, 25, 50%) to study the gradation, void ratio and, compaction characteristics. A machine has been manufactured to elucidate the maximum void ratio using a developed and manufactured linear-axis 3D clay printer arm. The geotechnical properties of sand-waste mixes delineated in this study reveals the enhancement in compaction and gradation characteristics of dune sand. According to the results, the binary mixture of dune sand with 25% of marble waste and 50% of reservoir sediment gives the highest maximum dry density. Thus, for improving dune sand’s geotechnical characteristics, the addition of fine marble waste and reservoir sediment to the dune sand is an environment-friendly solution.

Abstract: Plain Concrete pipes serve as effective underground infrastructure lines especially as sewer lines and culverts. The installation quality has a high effect on the performance of the buried pipe-soil system besides the pipe material strength. In this research, experimental investigation of buried plain concrete pipes installed in gravelly-sand soil and subjected to strip loading platform as surface loading to search the effect of the bedding compaction on the pipe. Granular soil bedding is a traditional material surrounding concrete pipes. An experimental testing program for two precast plain concrete pipes has 300 mm inner diameter was conducted in a laboratory soil box test facility. Loading on a pipes-soil system were applied up to collapse. Circumferential strain in pipes was measured by means of strain gauges in addition to the measurements of displacement developed in the vertical direction by means of a linear variable differential transformer (LVDT’s) and dials gauges. It is concluded that in case of loose bedding, a higher bedding factor of 1.83 is produced in comparison with dense bedding which produces a bedding factor of 1.49, thus yields that the quality of installation is improved with relatively loose bedding under the pipe.

Abstract: In this study investigates utilizing of slag as an additional material to improve engineering properties of contaminated soil by crude oil to changing the engineering characteristics to be satisfying and compatible, this is due to its pozzolanic reactivity. The aim of this study the impact of slag material in geotechnical engineering and to stabilize properties of contaminated soils. Two percentages of slag were utilized in this study, which is 0% and 6%. Compaction and direct shear strength tests had been conducted on the artificial contaminated prepared soil samples. In the results, showed that the increasing of slag leads to a decrease in the optimum water contents while the maximum dry density values increase. Furthermore, the shear strength is improved by utilizing slag so that slag can be considered as a stabilizing material to improve the properties of contamination soil.