Foundation Layer Research Articles

Influence of Sand Gradation on Volumetric Weigh and Compressive Strength of Pavement Foam Mortar

Abstract Foam mortar is a substitute for sub-base layers and base layers in road pavement construction on peat soil, which has the advantages of lightness, strength, and self-compacting. Sand is one of the building blocks of foam mortar. The purpose of the study was to analyze the effect of the gradation of sand on the resulting physical and mechanical properties of foam mortar (foam concrete). In this research, six gradations of sand were made (gradations of 3 sand sources and 3 gradations based on pusjatan standards) and then used in the manufacture of foam mortar and analyzed for volumetric weigh and compressive strength. Foam mortar from the six gradations of sand, it is concluded that gradation no. 6 (lower limit of pusjatan gradation) with a value of volumetric weigh is 0.97 t/m3 does not float perfectly in water, and no. 1 to 5 (gradation of 3 sand sources and 2 gradations of Pusjatan upper limit and middle) with a volumetric weigh is 0.83 t/m3 - 0.93 t/m3 floats in water. The compressive strength values of the 6 gradations are above 2000 kPa and can be used as foundation layers in road pavements.

Performance Analysis of Recycled Asphalt Material Foundation Layer and Top Foundation Layer Reviewed from Primary Displacement

This study aims to determine the unconfined compressive strength of recycled materials based on variations in cement content of 1%, 3%, and 5%, as well as the percentage of emulsified asphalt. This study is urgently needed because the massive development of road infrastructure drives an increase in the need for road materials. Utilization of recycled waste from existing asphalt layers and foundation layers is an alternative sustainable and environmentally friendly material. Reusing this material is more efficient if the road damage has not reached the structural stage. Testing in the study was conducted experimentally at the Road Materials Center Laboratory, Bandung, using materials from existing asphalt layers and foundations. Testing includes physical analysis of the material, compaction to determine the optimum water content and maximum dry density, and unconfined compressive strength. The results showed that the unconfined compressive strength with cement content of 1%, 3%, and 5% were 0.70 MPa, 1.70 MPa, and 2.09 MPa, respectively, with primary displacement values ​​of 20 mm, 25.8 mm, and 24.7 mm. Meanwhile, the residual strength value decreased with increasing cement content, namely 76.3%, 66.3%, and 64.3%.

Assessing the effect of offline topography on electrical resistivity measurements: insights from flood embankments

Summary Electrical resistivity tomography (ERT), a geophysical imaging method, is commonly used on flood embankments (dykes or levees) to characterise their internal structure and look for defects. These surveys often use a single line of electrodes to enable 2D imaging through the embankment crest, an approach that enables rapid and efficient surveying compared to 3D surveys. However, offline variations in topography can introduce artefacts into these 2D images, by affecting the measured resistivity data. Such topographic effects have only been explored on a site-specific basis. If the topographic effects can be assessed for a distribution of embankment geometries (e.g. slope angle and crest width) and resistivity variations, it would allow for targeted correction procedures and improved survey design. To investigate topographic effects on ERT measurements, we forward-modelled embankments with different trapezoidal cross-sections sat atop a flat foundation layer with contrasting resistivity values. Each was compared to a corresponding flat model with the same vertical resistivity distribution. The modelling workflow was designed to minimise the effect of forward modelling errors on the calculation of topographic effect. We ran 1872 unique embankment forward models, representing 144 geometries, each with 13 different resistivity contrasts. Modelling results show that offline topography affects the tested array types (Wenner-Schlumberger, Dipole-Dipole, and Multiple-Gradient) in slightly different ways, but the magnitudes are similar, so all are equally suitable for embankment surveys. Three separate mechanisms are found to cause topographic effects. The dominant mechanism is caused by the offline topography confining the electrical current flow, increasing the measured transfer resistance from the embankment model. The two other mechanisms, previously unidentified, decrease the measured transfer resistances from the embankment model compared to a layered half-space but only affect embankments with specific geometries and resistivity distributions. Overall, we found that for typical embankment geometries and resistivity distributions, the resistivity distribution has a greater control on the magnitude of the topographic effect than the exact embankment geometry: the subsurface resistivity distribution cannot be neglected. 2D inversions are suitable when both the embankment is more resistive than the foundations and when the embankment's cross-sectional area is greater than 4 m2/m2 (area scaled to an embankment with a height of 1 m). Topographic corrections, 3D data acquisition or 3D forward models are required when these conditions are not met. These are demonstrated using field data from an embankment at Hexham, Northumberland, UK. Improving the accuracy of the resistivity values in ERT models will enable more accurate ground models, better integration of resistivity data with geotechnical datasets, and will improve the translation of resistivity values into geotechnical properties. Such developments will contribute to a better characterised and safer flood defence network.

Effect of Calcium Carbide Residue on Shrinkage Mechanism of Clayey Subgrade Soil

ABSTRACT Calcium carbide residue (CCR) has been identified as an effective replacement for traditional lime for the stabilization of expansive soils. The shrinkage of expansive clay severely threatens the foundation layers’ long-term stability. The efficacy of CCR stabilization in reducing compressibility and enhancing the strength and stiffness of clay has been widely reported; however, the calcium-based additive stabilized soil tends to lose its engineered integrity under field-exposed seasonal moisture variation, specifically, shrinkage induced by prolonged drying. In this study, the shrinkage characteristic of CCR-treated clay (6%, 9%, and 12%) slurry was investigated by digital image analysis and mercury displacement method to quantify volumetric shrinkage strain. The results were compared with those of 4% and 6% lime-treated clay, which revealed the higher efficacy of CCR in reducing shrinkage strain by 47–57%. A characteristic shrinkage curve that depicted the significant variation of shrinkage phases in CCR-treated clay samples is developed. The dominance of the proportional shrinkage phase is observed in both untreated and treated clay samples. The shrinkage caused by evaporation, hydration, and decalcification is postulated in treated clays. This study is expected to contribute to the understanding of shrinkage mechanisms of CCR-treated clay and assist in the future design of stabilized embankment sections or subgrade for unpaved roads.

Comparative Study of Airport Layer Thickness Planning Between US Army Corp Graphical Method and Federal Aviation Administration (FAA) PCN-ACN and PCR-ACR Method

Airport pavement is designed following the US Corporation of Engineers method or better known as the California Bearing Ratio (CBR) method and the FAA (Federal Aviation Administration) method which issues regulations for calculating airport pavement structures, namely AC (Advisory Circular) 150_5320_6D which same as the method CBR. In 2021, the FAA issued a standard for calculating airport pavement structures, namely AC (Advisory Circular) 150_5320_6G which uses the FAARFIELD assistance program. The difference in pavement thickness is at most 7.6 cm, on the flexible pavement type base course. In the FAARFIELD Auxiliary Program, all aircraft loads are taken into account as a contributor to pavement damage indicated by the CDF value that can accommodate aircraft loads, in contrast to the graphical method where aircraft are converted to design aircraft. The thickness of the base course using the graphical method is greater than that of the FAARFIELD Assistance Program, this is because when performing calculations, the initial base course value is the minimum value based on the minimum base course table for the use of top foundation layer material (AC No.150_5320_6G). The thickness of the surface course pavement is the same according to FAA provisions for the critical thickness of the surface course which is 4 in or 102 mm.

Derajat Kepadatan Lapis Pondasi Agregat Tanpa Penutup Aspal Menggunakan Metode Sand Cone pada Proyek Rekonstruksi Jalan Kecamatan Serai Serumpun, Kabupaten Tebo di Ruas Jalan Tanjung Aur Seberang-Malako Tinggi

Road infrastructure is very important for the economic progress of Tanjung Aur Seberang village residents. Economic development in Tanjung Aur Village, Tebo Regency has significantly increased traffic levels. If this is not balanced by improving the quality of transportation facilities and infrastructure, then this could cause serious problems. Determining the value of the degree of density of the foundation layer aggregate (soil) class S in obtaining soil stability with safe conditions in accordance with the requirements of density standards is the aim of this research. The methods used are direct tests in the field and in the laboratory. Testing soil density in the field using a sand cone tool follows the provision stated in SNI 03-2828-1992, while testing soil density in the laboratory follows the provisions stated in SNI 1742-2008. Soil density testing intervals vary between 50 meters, 75 meters, 100 meters, 150 meters, 200 meters depending on location conditions. The results sand cone testing was carried out on roads from STA 2+000 to 3+800. In the first test with 9 test points, the field density was obtained below 95%, namely STA 2+100 (94,141%), STA 2 +550 (94,389%) and STA 3 +800 (94,289). Theses results indicate that the required standard degree of field density has not been achieved, so that the base layer of class S aggregate can be added and compaction can be carried out again. And from STA 0 + 005 to 4 + 200 in the second test with 26 test points. Test results using a sand cone tool show that the average water content value is 7.513% with a density reaching 98.846%. and these results were in accordance with applicable standard requirements.

Effects of 3D Geocells on Flexible Pavement Foundations

Abstract: The current below study examines the effects of adding a Cubic Three-dimensional Geo-synthetics material known as Geo-cells to the foundation layer of flexible Bitumen pavements. In this study, the test of California bearing ratio (CBR) of 5% is used to compare the steel reinforced and unreinforced pavement made sections built on that subgrade. To comprehend the impact of Geo-cell reinforcement upon the pavement section's load-carryings mechanism under static and repetitive loading circumstances, a number of model tests were conducted. The following characteristics were examined: surface deformation profile the test sections, real rut subgrade level, load-settlement response of the pavement sections, and pressure is transmitted into the subgrade soil beneath into the Geo-cell reinforced foundation layer.

TINJAUAN TEBAL PERKERASAN PADA RUAS JALAN MARISA-MOTOLOHU IV KABUPATEN POHUWATO

Review of Pavement Thickness on Marisa Motolohu IV Road Section, Pohuwato Regency Marisa – Motolohu IV Road is a collector road which is a very useful transportation in the community and a road to agropolitan access in Pohuwato Regency, Gorontalo Province. In improving the road, adequate studies are needed to achieve optimal benefits. Road pavement thickness planning uses the SNI/AASHTO 93 method. Traffic enumeration surveys are carried out on road sections located in the study area. Subgrade research to find representative CBR values. In this planning stage, the criteria considered in this planning are traffic volume, time limits, traffic loads, reliability, environmental conditions, road performance criteria, drainage factors. Field conditions (existing) on ​​the Marisa – Motolohu IV section are (D1) 5.0 cm, base layer (D2) 10.0 cm, subbase layer (D3) 15 cm. The results of the study obtained the thickness of each pavement, namely: surface layer (D1) 8.0 cm, upper foundation layer (D2) 13 cm, lower foundation layer (D3) 19 cm. This study can be used as a comparison in previous planning using different methods.

Practical Appearance Model for Foundation Cosmetics

AbstractCosmetic products have found their place in various aspects of human life, yet their digital appearance reproduction has received little attention. We present an appearance model for cosmetics, in particular for foundation layers, that reproduces a range of existing appearances of foundation cosmetics: from a glossy to a matte to an almost velvety look. Our model is a multilayered BSDF that reproduces the stacking of multiple layers of cosmetics. Inspired by the microscopic particulates used in cosmetics, we model each individual layer as a stochastic participating medium with two types of scatterers that mimic the most prominent visual features of cosmetics: spherical diffusers, resulting in a uniform distribution of radiance; and platelets, responsible for the glossy look of certain cosmetics. We implement our model on top of the position‐free Monte Carlo framework, that allows us to include multiple scattering. We validate our model against measured reflectance data, and demonstrate the versatility and expressiveness of our model by thoroughly exploring the range of appearances that it can produce.

Influence of Foundation Layer Strength on Slope Stability When Water Level Drops Slowly

Influence of Foundation Layer Strength on Slope Stability When Water Level Drops Slowly

ANALISIS LIFE CYCLE COST PERKERASAN KAKU DAN LENTUR JALAN PROVINSI (STUDI KASUS: JALAN RAYA PARE – KEDIRI)

Pare-Kediri Highway is a provincial road which is the main connecting road between Pare and Kediri City. On this road section is often bypassed by vehicles with large loads. However, in existing conditions there is damage that varies. Road planning is generally planned to be used for a certain period of time, for example 10 to 20 years depending on existing transportation needs, in the hope that the road will remain in good condition and suitable for traffic. Road maintenance measures are necessary to ensure good operating conditions throughout the planning period. Maintenance and repair of damaged roads also cost a lot. As a result evaluating road damage and choosing the right type of repair is very important. According to the results of research with the 2017 pavement Design Manual guidelines, flexible pavement thickness was obtained including AC-WC 4 cm, AC-BC 6 cm, AC-Base 16 cm and Class A aggregate foundation layer 15 cm. While the thickness of the rigid pavement using continuous concrete without reinforcement with 30 MPa quality concrete obtained plate thickness of 28.5 cm and a layer of thin concrete foundation (LMC) 10 cm. Based on data processing, the construction cost of flexible pavement amounted to Rp 12,958,812,587.00 while rigid pavement amounted to Rp 30,584,262,345. 00. The Total maintenance cost for flexible pavement is Rp 23,836,678,414.33 while for rigid pavement is Rp 3,208,462,265. 15. So that the results of life cycle cost analysis of this study obtained the total cost during the 20-year life cycle of flexible pavement of Rp 36,795,491,001.33 while rigid pavement of Rp 33,792,724,610. 15. In this case, rigid pavement has a life cycle cost (life cycle cost) which is 8.51% more efficient than flexible pavement.

Practical experience of installing an artificial base for industrial floors

The installation of artificial foundations for industrial buildings and constructions (industrial floors) is becoming more and more relevant in modern construction, as the number of satisfactory sites for development is decreasing, territories with complex geological and hydrogeological conditions are increasingly being used. A high-quality installation of an artificial base should ensure the durability, strength and stability of the structure. When preparing the site and arranging the artificial base, it is necessary to take into account such important factors as the type of soil, the level of groundwater, the expected load on the floor and the type of floor covering. Compliance with the requirements of regulatory and technical documentation, the use of quality materials and professional execution of work are critical for the successful construction of industrial floors. As part of the study, an overview and detailed description of the process of installing an artificial base for industrial floors was carried out on the example of a real construction, a warehouse complex with an area of 35,000 m² in the south-western outskirts of the city of Kyiv. The article highlights that the foundation installation process includes two main stages: site preparation and creation of artificial foundation layers. The preparation of the site includes cleaning and planning of the territory, removing and removing the fertile layer of soil, conducting engineering and geological studies and implementing measures for the engineering protection of the territory. The arrangement of the artificial base includes the compaction of the existing soil layers, the creation of new artificial base layers and their mechanical compaction in combination with the reinforcement of the layers with geosynthetics materials (geogrids). This study emphasizes the importance of a comprehensive approach to site preparation and artificial base installation, which allows for reliable and long-term operation of industrial floors, minimizing the risks of deformation and damage.

Flexible Pavement Design Using Bina Marga 2017 Method for The Padang Mengatas Road Section in Lima Puluh Kota Regency

Kota Payakumbuh and Kabupaten Lima Puluh Kota are experiencing rapid development in the fields of economy and tourism, attracting many visitors from both local and out of town. The increase in new tourist destinations has increased traffic movement in these areas. This research was conducted to plan flexible pavement using the Bina Marga 2017 method on the Padang Mengatas road section, aiming to improve future transportation comfort and meet the increasing traffic needs, thereby supporting economic and tourism growth in the region. This study uses a quantitative method, where the initial evaluation determines the Average Daily Traffic (ADT) and soil data (field CBR), essential information for pavement design. The research results show that the flexible pavement layer using the Bina Marga method has a CBR value of 3.1% and an ADT of 5792 vehicles per day. The recommended pavement layers consist of AC-WC with a thickness of 4 cm, AC-BC with a thickness of 6 cm, and a top foundation layer with a thickness of 40 cm.

Studying the Impact of Soil Stabilization Techniques on Rigid Pavement Joints Across Various Axle Loads

Rigid pavement slabs are erected on a prepared subgrade or foundation layer, providing a hard and continuous surface. Transverse joints made of dowel bars connect them, and longitudinal joints made of tie bars join them longitudinally. This study is an investigation of the impact of soil strength and concrete parameters on the effectiveness of dowel bars in rigid pavements. Moreover, three parameters were examined; California Bearing Ratio (CBR), concrete compressive strength and slab thickness. The analysis was conducted using the Ever FE program and focused on several axle configurations applied to the joint. The results indicate inverse association between the pavement slab thickness and the concrete strength, under the assumption of consistent soil strength. Moreover, an assortment of reduced shear forces on the dowel bars is seen when the soil strength values increase. It indicates that soil strength has a greater impact on the shear load of dowel bars compared to the qualities of concrete. Additionally, the type of axles used and the magnitude of soil strength were shown to have a significant effect on the shear load.

Analysis of Kinang Jingkion Material as Road Subbase Layer Using Soil Cement Method

This research aims to analyze the California Bearing Ratio (CBR) and Unconfined Compressive Strength Test (UCS) values as road foundation layers using local materials, namely Kinang Jingkion. The soil and Kinang Jingkion materials for the study were taken from the Apalapsili quarry in Yalimo Regency. Additionally, the additive or soil stabilizer used was matos obtained from the testing of soil characteristics, including sieve analysis or gradation, Standard Proctor Test for light density, and liquid limit test. After testing, it was found that the soil from the Apalapsili quarry is granular soil and can be categorized as A-1-a according to SNI 03-6797-2002. Subsequent testing involved CBR and UCS testing on Mix Designs made of soil and cement with concentrations of 4%, 6%, and 8%. Next, additional Mix Designs were created with compositions of Kinang Jingkion, soil, cement at 4%, 6%, and 8%. Further Mix Designs included compositions of Kinang Jingkion, soil, matos at 2%, and cement at 4%, 6%, and 8%. From the UCS testing results, Mix Designs with soil and cement concentrations of 4% and 6% did not meet the compressive strength criteria, with compressive strength values of 9.26 Kg/Cm² and 17.4 Kg/Cm² respectively. According to SNI 6887-2012, the compressive strength value after 7 days of immersion should be within 25-35 Kg/Cm², while other Mix Designs met the criteria of SNI 6887-2012. CBR testing also utilized the same Mix Designs, and the highest CBR result was obtained from the Mix Design with compositions of Kinang Jingkion, soil, cement at 8%, and matos at 2%, with a CBR value of 112%. According to the 2018 Revised General Specifications, a CBR value of 112% indicates a Class A Foundation Layer.

Correlation Between Dynamic CBR and Compaction and Bearing Capacity of Pavement Foundation Layers

Correlation Between Dynamic CBR and Compaction and Bearing Capacity of Pavement Foundation Layers

Method of settlement calculation for underlying layer of soft soil composite foundation based on load transfer mechanism

The mechanical properties of soil in soft soil area are poor, and the settlement of the underlying layer in the composite foundation accounts for a large proportion of the total settlement. At present, most of the research focuses on the settlement of the reinforced area, and the research on the settlement of the underlying layer is of great significance for the settlement of soft soil composite foundation. The differences in load transfer modes of soil and pile are analyzed, and based on the Boussinesq solution and Mindlin solution, a calculation method for the stress and settlement of the underlying layer in flexible and rigid pile composite foundation is proposed. The relative displacement of soil and pile in flexible pile composite foundation is small, and the negative friction can be ignored, but the influence of effective pile length should be considered. The relative displacement of soil and pile in rigid pile composite foundation is large, so the negative friction should be considered. Part of soil top stress is transmitted to the pile via negative friction, and then the pile axial force is transmitted back to the soil via positive friction. In addition to effective pile length, the change of stress transfer path caused by negative friction should also be considered in settlement calculation.

Land subsidence along the Beijing-Tianjin high-speed railway before and after the South-to-North water diversion project with multi-source monitoring datasets

The development of land subsidence has seriously affected the safe operation of Beijing-Tianjin high-speed railway. The South-to-North Water Diversion Project Central Route (SNWDP-CR) was officially put into operation in December 2014. It has changed the water supply pattern in Beijing and provided conditions for reducing groundwater exploitation and controlling land subsidence. In this paper, the time-series interferometric data, in situ monitoring data of recent 20 years and the basic geological datasets are combined to compare and analyze the changes of groundwater level, land subsidence and the main subsidence layers along the Beijing-Tianjin high-speed railway before and after the SNWDP-CR. The effects of the environment of Quaternary sedimentary, groundwater exploitation and soil deformation of different lithology on land subsidence along the high-speed railway under the background of new water conditions are revealed. The main conclusions are as follows: 1) The serious land subsidence area along the Beijing-Tianjin high-speed railway always concentrated in the section of DK11-DK23. After the operation of SNWDP-CR, the land subsidence along the railway generally showed a slowing trend. The maximum subsidence rate was reduced from 80 mm/yr to 49 mm/yr. The length of subsidence rate that more than 50 mm/yr of the section was reduced from 8.0 km to 0 km. 2) The groundwater level of different aquifer groups along the Beijing-Tianjin high-speed railway rose and declined before and after the SNWDP-CR. in eastern part of the plain, the groundwater level of each aquifer group has changed from a continuous decline (range 0.13–1.82 m) to a gradual rise (range 0.45–1.87 m) since 2017. However, in the southeast of the plain, the groundwater level still showed a continuous decline trend, with an average annual decline of 1.2–1.8 m. 3) From 2006 to 2019, the subsidence of the first, second and third compression layer group along the railway accounted for 2.71%, 28.29% and 69%, respectively. The third compression layer group (monitoring layer 94–182 m) had the largest subsidence proportion and was the main subsidence layer. 4) The land subsidence along the Beijing-Tianjin high-speed railway is controlled by the basement structure. The difference of groundwater exploitation intensity led to differences in the spatial distribution of land subsidence along the railway. The subsidence of the soil layer below the bearing layer (about 50 m) of the high-speed railway pile foundation exhibited the characteristics of viscoplastic or viscoelastic plasticity deformation. This section of strata is a key layer that needs to be considered for land subsidence control along the Beijing-Tianjin high-speed railway in the future.

Improved of Mechanical Characteristics of Gargar Mud by Mineral Additives

The operational dams in Algeria lose 32 million m3 of water storage capacity each year, and fifteen of these dams are threatened by siltation. This investigation forms a component of a management strategy for dredged silt in the Gargar Dam, the third-largest dam in Algeria with considerable sedimentation. This paper comprises two main axes: a detailed experimental study based on the studied dam mud's physico-chemical, rheological, and mechanical analysis. The second part is based on the study of the valorization of Gargar mud to be acceptable for use in road civil engineering. In order to obtain this goal, the Gargar mud was treated with lime (0-6%), sand (20%), and natural pozzolana (20%). Test results show that the properties of Gargar mud are significantly improved after treatment, and the soil becomes more friable and more resistant; it can therefore be used as a foundation layer in road civil engineering.

Stabilization and Recycling of Sand in Pedestrian Walkways

The production of construction and demolition waste (CDW) in urban areas is growing rapidly. While the storage and disposal of CDW waste is costly, its recovery can help to conserve natural resources. This study investigates the characteristics of recycled sand obtained from the processing of CDW waste and the possibility of its reuse for pedestrian pathways. Physico-chemical and mineralogical characteristics of the recycled sand were investigated for its reuse. The percentage of fine particles in sand (below 0.63 μm) is 2.8%. The grain size of sand fulfills the particle size requirement of French standards. The methylene blue value of sand is 0.05 g/100 g. The GTR classification of recycled sand is D2 which is insensitive to water and suitable for road applications. A mineralogical analysis of soil shows that quartz, albite and microcline are important minerals in recycled sand. XRF analysis shows that CaO and SiO2 are major oxides in the recycled sand. The characterization of sand was followed by a manufacturing of cylindrical specimens of sand to observe the compressive strength. Samples were compacted with dynamic compaction by applying the Proctor normal energy of 600 kN·m/m3. The compressive strength testing of specimens shows that non-stabilized sand samples have compressive strength around 0.1 MPa which is considerably lower for its reuse in pedestrian pathways and road applications. Due to the low bearing capacity of sand, recycled sand was stabilized with the addition of binders such as Rolac (hydraulic binder), ground-granulated blast furnace slag (GGBS) and ECOSOIL® (slag mixes) with different percentages of the binder ranging from 0 to 7% for the optimization of the binder and for economic efficiency. The compressive strength of sand samples increases with the increasing percentage of the binder. The increase in strength is more important with a higher percentage of binders (5%, 6% and 7%). At a 7% binder addition, specimens with Rolac, GGBS and ECOSOIL binders show the compressive strength of 1.2 MPa, 0.5 MPa and 0.5 MPa. At a 7% Rolac addition, specimens have a compressive strength higher than 1 MPa and meet the strength requirement for soil reuse in the foundation and subbase layers of roads with low traffic. The experimental work shows that recycled sand can replace conventional quarry sand for road applications and pathways with the addition of a local binder, which is an eco-friendly and economical practice.