Compaction Energy Level Research Articles

Response surface regression and machine learning models to predict the porosity and compressive strength of pervious concrete based on mix design parameters

This study investigates the influence of aggregate size, aggregate-to-cement ratio, and compaction effort on pervious concrete's porosity and compressive strength. It proposes using response surface methodology and machine learning techniques to predict porosity and compressive strength. Fifteen mix designs (three aggregate sizes and five aggregate-to-cement ratios) with seven compaction energy levels were employed. Experimental data analysis using various regression models revealed that the quadratic model provided the best fit for predicting both porosity and compressive strength. Machine learning models were employed to predict porosity and compressive strength more accurately. Among the models investigated, the artificial neural network achieved superior performance across all datasets (training, testing, and validation). This suggests the artificial neural network model can effectively capture the complex relationships between input and response variables. Sensitivity analysis using SHAP (SHapley Additive exPlanations) revealed that compaction energy significantly impacts both porosity and compressive, while aggregate size has the most negligible influence.

Influence of Compaction Energy on the Mechanical Performance of Hot Mix Asphalt with a Reclaimed Asphalt Pavement (RAP) and Rejuvenating Additive

The Mexican asphalt paving industry is increasingly interested in using reclaimed asphalt pavement (RAP) to produce hot mix asphalt (HMA) due to its economic and environmental advantages. However, an ill-defined methodology for integrating RAP into the HMA mix design has hindered its use. This paper investigates how compaction energy affects both rejuvenated and non-rejuvenated recycled HMA mixtures. A Superpave gyratory compactor was used to determine the optimal binder content and find a balance between flexibility and stiffness that meets cracking and rutting resistance requirements. Various recycled HMA mixtures were subjected to different compaction energy levels (75, 100, and 125 gyros), different RAP contents (15%, 30%, and 45%), and various dosages (10%, 15%, and 36%) of the rejuvenating additive Maro-1000®, following the blending chart. Performance was evaluated using the Hamburg wheel tracking test (HWTT) and the fracture energy flexibility index test (I-FIT). The results demonstrate that mixtures with RAP, a rejuvenating admixture, and varying compaction energies exhibit favorable mechanical behavior. However, both rejuvenated and non-rejuvenated mixes with 15% RAP showed performance comparable to conventional mixtures. They improved stiffness by up to 46% while reducing the flexibility index to 25%, striking a balanced equilibrium between rutting resistance and cracking susceptibility.

Converting optimum compaction properties of fine-grained soils between rational energy levels

This study introduces a practical energy conversion (EC)-type modeling framework capable of converting the optimum compaction properties of fine-grained soils between any two rational compaction energy levels (CELs). Model development/calibration was carried out using a database of 242 compaction test results — the largest and most diverse database of its kind, to date, entailing 76 fine-grained soils (covering liquid limits of 16–256%), with each soil tested for at least three different CELs. On establishing the framework, an independent database of 91 compaction test results (consisting of 34 fine-grained soils tested for varying CELs) was employed for its validation. The proposed EC-based models employ measured optimum water content (OWC) and maximum dry unit weight (MDUW) values obtained for a rational CEL (preferably standard Proctor) to predict the same for higher and/or lower compactive efforts (covering 214–5416 kJ/m3). The 95% lower and upper statistical agreement limits between the predicted/converted and measured OWCs were obtained as −2.16 wc % and +2.25 wc %, both of which are on par (in terms of magnitude) with the ASTM D1557 allowable limit of 2.1 wc %. For the MDUW predictions, these limits were calculated as −0.71 and +0.66 kN/m3, which can also be deemed acceptable when compared against ASTM’s allowable limit of ±0.7 kN/m3 (= ±4.4 lb/ft3). The proposed framework offers a reasonably practical procedure to accurately convert the optimum compaction parameters across different CELs (without the need for any soil index properties), and thus can be used with confidence for preliminary project design assessments.

Compaction Control Using Degree of Saturation and Plasticity Index on Tropical Soil

Soil compaction in the field is conventionally controlled using maximum dry density, (ρd)max, and optimum moisture content, (w)opt, as the target properties. However, achieving accurate control of these target properties can be difficult due to variation of compaction energy level (CEL) and soil type. Recently, a novel soil compaction control approach using optimum degree of saturation, (Sr)opt, as the target properties has been proposed. It was argued that (Sr)opt can be a better compaction control property as the value is less sensitive to the variation of CEL and soil type. This paper presents an investigation of the compaction characteristics of tropical soils from several locations in Indonesia based on both primary and secondary data. This study was performed by exploring the relationships between (i) dry density (ρd) and Sr, (ii) (ρd) and plasticity index (PI), (iii) (ρd) and CBR, as well as (iv) (ρd) and permeability. This study showed that the (Sr)opt of the soils was 91.2%, with variation between 81.2% and 96.5%. This study also showed that (ρd)max can be related to PI at a given CEL. It is expected that the proposed relationships can be better references for field compaction control practices in Indonesia.

Optimal density for effective chemical stabilization of deficient soils for road structures

Clays are deficient soils in pavement construction due to presence of secondary clay minerals which are usually stabilized to improve its engineering properties. Calcium carbide residue (CCR) and Zeolite wastes have both been identified as soil stabilization additives due to presence of calcium ion in the CCR and amorphous silica in zeolite. However, various researchers uses varied compaction energy level to mold specimen for relevant tests. This study is aimed at compacting CCR and zeolite treated clay at five different energy levels to determine the energy level that gives the highest strength and stability. For each compaction energy, the untreated and treated clay were prepared and some selected mixtures were sent for microstructural tests. Unconfined compressive strength (UCS) and California bearing ratio (CBR) specimen were cured tested at predetermined maximum dry density (MDD) and Optimum moisture content (OMC). The MDD increased with compaction energy while the OMC reduced in the same order. The XRD micrograph of specimen treated with CCR and zeolite revealed disappearance of delayed ettringite peaks from untreated clay with formation of microcline and anorthite. The SEM showed the formation of cementitious calcium silicate hydrate (C-S-H) filling the pores in the untreated clay to form a compact mass. The unconfined compressive strength (UCS) increased to 2300kN/m2 for the treated clay after 180 days curing. The CBR values increased from 3% for untreated clay to 260% for treated clay. The durability test showed result of between 72% and 84% for treated clay which satisfy the 70% minimum specified by standard. These UCS and CBR values satisfy the requirement for sub-base of highly trafficked roads. The UCS and CBR results for specimen cured for 180 and 60 days respectively revealed that the optimum compaction energy for effective CCR and zeolite stabilization occurred in Reduced Modified Proctor energy level.

Development and validation of a degree of saturation prediction model using time domain reflectometry for compaction control

Compaction quality is directly related with the shear strength of soils. Inadequately compacted soils have lower shear strength that decrease the load bearing capacity and increase the differential settlement of the pavement, which may endanger safety and durability of the highways. Although intelligent compaction technology has enhanced the quality control of the compaction, conventional evaluation methods adopting sampling from random locations to determine relative compaction are extensively used in most of the earthwork projects. However, relative compaction may lead misjudgment, since the compaction energy level and the soil type in-place cannot match exactly with the given specifications of an earthwork project. Recent studies have shown that soil degree of saturation (Sr) can be utilized as an alternative control parameter for compaction quality. Sr in-place is usually determined with sand cone method. The method is time consuming as well as prone to error due to potential water seepage and deformation of soft soils. With its ability to provide remote and continuous monitoring in real time, Time Domain Reflectometry (TDR) has the potential to serve as a viable alternative method for determination Sr in-place. This research presents models developed using different calibration methods for the prediction of Sr with TDR measured dielectric permittivity. The accuracy of the models was evaluated with cross-validation. The results show that TDR is able to predict the Sr with less than ±5% deviation for 93% of the specimens in the validation set within the saturation ratio range of 0.01–0.93 cm3 cm−3 with an appropriate model.

Role of Clay Mineralogy in the Estimation of Permeability Coefficient in Compacted Fine-grained Soils

The foundations constructed upon the soils are depending upon the three major criteria i.e., strength, stiffness, and stability. In all three cases, the subsoil is expected to be in a compacted state. In coarse-grained soils, the result of compaction is a problem of substantiality, whereas physicochemical sort of response for fine soils. There is comparatively limited research known about the effects of clay mineralogy on the permeability properties of fine-grained soils, as well as different placement conditions and energy levels. In this study, consolidation behavior will be estimated for the six field soils and one artificial soil having different liquid limits, the Mineralogical composition of clay, and its plasticity properties under placement conditions like 95% of the γd max on dry and wet sides, and at OMC. The permeability behavior of these soils under study is computed by calculating the IS Light and Heavy Compaction energy levels' corresponding consolidation properties (Cv and Mv) using five practical approaches that have been described in the literature. The coefficient of permeability (K) of soils is calculated accurately with a fair degree of accuracy by 1-D consolidation test data like Cv and Mv. The estimated values of K were compared with the K values obtained from experimental studies under various stages of loading, and it was observed that there was good agreement between the two. These results were validated using Abaqus software through Finite Element Modelling analysis.

Influence of soil compaction and moisture variation on development of sesame (sesamum indicum l.) plant in a sandy loamy soil

This study determines the influence of soil compaction on shoot, root development and nutrients uptake of sesame (sesamum indicum l.) plant in a sandy loamy soil. The research was carried out in Mokwa local government of Niger state during wet season. Three soil samples of 300g weight from the top 20cm of the soil profile were taken from college farm. The initial moisture content of the soil was determined using oven-drying method. The soil samples were air dried, large clods broken and grounded. The soil samples were then mixed to obtain a homogenous mixture of the sample. The soil moisture content was then raised to varying moisture levels of 10%, 12%, and 14% exceeding the optimum moisture content of sandy loam which is 12% moisture. Each sample was subjected to five levels of compaction energy using 0,5,10,15,20 blows of a standard proctor hammer in cylindrical cores of 17cm in height and 10cm diameter in accordance with the standard proctor compaction procedure. Four holes were made in each can and four seeds were sown in each hole to be thinned into one seed per hole (four plants in each can). The depth of sowing was one cm. The seedlings were tinned to a maximum of five (5) per core at 15 days after planting. The heights (cm) of the seedling were taken with a measuring tape at 5-days interval to 20 days after planting. The experiment was laid out in randomized complete block design (RCBD). The data collected were subjected to descriptive statistical analysis, regression analysis and analysis of variance. The results from the soil physical properties analysis shows that the soil is sandy loam with sand being 76.8 % and clay as 11.2%. The bulk average density was 1.75 g/cm3. Results obtained from the study shows that compactive efforts significantly affect plant growth and development. It also shows that as compactive effort increases, the soil bulk density and penetration also increases. The effect of number of hammer blows on soil bulk density and penetration resistance was significant. The effect of excessive moisture also affects germination and plant growth. Moderate soil compaction has beneficial effect. This is due to greater water retention. In general, it appears that there is a great potential in growing sesame on sandy loam soil, if the level of compaction is maintained at moderate level, which does not impede root development and other plant requirements.

Stress dependent behaviour of unbound layers of unselected construction and demolition waste aggregates by lightweight deflectometer tests

The use of construction and demolition waste (CDW) aggregates in unbound road pavement layers is increasing. However, the lack of data on performance in the field has spurred this investigation into their in-situ properties. A lightweight deflectometer (LWD) is a fast and simulative testing device for estimating the elastic modulus of unbound pavement layers. A field test pit was built to run LWD measurements on an unbound subbase layer containing CDW aggregates compacted at different energy levels. To assess their stress-strain non-linear behaviour, several LWD drops were performed on the same location by varying (i) the loading mass, (ii) the drop height, and (iii) the plate diameter. A stress-hardening behaviour of in-situ CDW aggregates was observed, consistent with the stress dependent evolution of resilient modulus of granular material commonly recorded in laboratory tests. The LWD modulus was found to be dependent on the level of compaction energy but also sensitive to the mechanical response of the layer below. The outcomes at this test pit suggest it would be wise to consider the rational evaluation of the in-field stress dependent behaviour of unbound CDW granular materials at both the design stage and when devising quality acceptance procedures. Nonetheless, to have a comprehensive interpretation of LWD results a greater uniformity of material properties and a stronger control of construction procedures will be desired, especially when heterogenous materials such as CDW aggregates are investigated.

Use of steel slag and LAS-based modifying admixture in obtaining highly eco-efficient precast concrete products

This paper presents a study on improving the eco-efficiency of no-slump concrete for precast elements using Basic Oxygen Furnace Slag (BOFS). Recycled BOFS powders and aggregates have been produced to obtain mixtures with better particle size distribution and improved packing density based on a particle packing method. A comprehensive experimental investigation was carried out on mixtures with different cement contents (5%, 10%, and 15% vol.) and compaction energy levels (6, 10, and 20 blows in a sand rammer). A modifying admixture based on Linear Alkyl Benzene Sodium Sulfonate (LAS) has also been evaluated as a workability and cohesiveness enhancer for steel slag concretes. In addition, concrete eco-efficiency was evaluated by measuring the binder intensity (bi) and waste consumption. The highest compaction energy provided packing densities ranging from 0.78 to 0.80, and BOFS aggregates led to better mechanical performances. The BOFS concrete containing 15% cement obtained the best strength (52.1 MPa) and bi value (7.0 kg/m³/MPa), with a waste consumption of 2356.57 kg/m³. The mixture with the lowest cement consumption (5% - 121.56 kg/m³) and the highest consumption of waste (2637.82 kg/m³) reached 16 MPa, delivering a bi of 7.6 kg/m³/MPa.

Experimental Study on Vibratory Compaction Behavior of Tunneling Rock Wastes Used as Unbound Permeable Aggregate Base Materials.

The tunneling rock wastes (TRW) have been increasingly generated and stockpiled in massive quantities. Recycling them for use as unbound granular pavement base/subbase materials has become an alternative featuring low carbon emission and sustainability. However, the field compaction of such large-size, open-graded materials remains challenging, thus affecting post-construction deformation and long-term stability of such pavement base/subbase layers. This study conducted a series of proctor compaction and new plate vibratory compaction tests to analyze the compaction characteristics of such TRW materials. A total of six different open gradations were designed from particle packing theory. In addition, the effects of gradation and compaction methods on the compaction characteristics, particle breakage of TRW materials, and the optimal combination of vibratory parameters were investigated by normalizing the curves of achieved dry density versus degree of saturation for various combinations of gradations, compaction methods, and compaction energy levels. The post-compaction characteristics of interparticle contact, pore structure, and particle breakage were analyzed from the X-ray computed topography (XCT) scanning results of TRW specimens with different gradations. The findings showed that the gravel-to-sand ratio (G/S) based gradation design method can effectively differentiate distinct types of particle packing structures. There exists an optimal G/S range that could potentially result in the highest maximum dry density, the lowest particle breakage, and the best pore structure of compacted unbound permeable aggregate base (UPAB) materials. The achieved dry density (ρd) of UPAB materials subjected to vibratory plate compaction exhibited three distinct phases with compaction time, from which the optimal excitation frequency range was found to be 25-27 Hz and the optimal combination of vibratory parameters were determined. The normalized compaction curves of degree of saturation versus achieved dry density were found insensitive to changes in material gradations, compaction methods and energy levels, thus allowing for a more accurate evaluation and control of field compaction quality.

Impact of Calcium Chloride on the Microstructure of a Collapsible ‎Soil

The study of the collapse of soils under the effect of flooding is a major problem in soil ‎mechanics. Most of the work done on the treatment of these soils has been devoted to ‎the use of binders of hydraulic or organic types. However, little work has been devoted to the use of salt calcium chloride in ‎collapsible soil treatments.‎ The purpose of this study is to evaluate the effect salt calcium chloride on a reconstituted collapsible soil in the laboratory, at ‎different levels of water content, compaction energy and concentration of the saline solution. The ‎results obtained showed a significant reduction in the potential for soil deformation ‎and an illustration and a noticeable interaction between the soil particles ‎and the saline solution resulting in a denser material.

Bio-fiber reinforced roller compacted concrete designed for road construction: feasibility of date palm fibers in pavements

The current study is an attempt to test the feasibility of bio-fibers for roller compacted concrete (RCC). Date palm fibers (DPF) were utilized as a filler to make a different type of RCC designed for road construction. An experimental investigation has been carried out to determine the effect of these fibers on two types of mixtures: (i) without air-entraining agent (AEA) (ii) containing AEA. The experiments were conducted with mixtures prepared, natural, and 0.1% DPF reinforced RCC. 12 mixtures were prepared with four levels of AEA (0%, 0.01%, 0.05%, and 0.1%) and two levels of compaction energy (CE) (2400 kJ/m3 and 4800 kJ/m3). They were tested for compressive strength, abrasion resistance (Cantabro test), and ultrasonic pulse velocity. Concerning durability, freeze–thaw resistance was investigated. The results showed that the inclusion of date palm fibers had an important effect, as, it not only improved the physical and mechanical characteristics, but also found to ameliorate the durability of RCC mixes significantly. Relationships between such factors test are completed using the factorial experimental design methodology to develop mathematical models for predicting RCC properties. The obtained results are promising for further reflection on a large scale to explore the issue of strengthening RCCs with bio-fibers.

Modeling the Compaction Characteristics of Fine-Grained Soils Blended with Tire-Derived Aggregates

This study aims at modeling the compaction characteristics of fine-grained soils blended with sand-sized (0.075–4.75 mm) recycled tire-derived aggregates (TDAs). Model development and calibration were performed using a large and diverse database of 100 soil–TDA compaction tests (with the TDA-to-soil dry mass ratio ≤ 30%) assembled from the literature. Following a comprehensive statistical analysis, it is demonstrated that the optimum moisture content (OMC) and maximum dry unit weight (MDUW) for soil–TDA blends (across different soil types, TDA particle sizes and compaction energy levels) can be expressed as universal power functions of the OMC and MDUW of the unamended soil, along with the soil to soil–TDA specific gravity ratio. Employing the Bland–Altman analysis, the 95% upper and lower (water content) agreement limits between the predicted and measured OMC values were, respectively, obtained as +1.09% and −1.23%, both of which can be considered negligible for practical applications. For the MDUW predictions, these limits were calculated as +0.67 and −0.71 kN/m3, which (like the OMC) can be deemed acceptable for prediction purposes. Having established the OMC and MDUW of the unamended fine-grained soil, the empirical models proposed in this study offer a practical procedure towards predicting the compaction characteristics of the soil–TDA blends without the hurdles of performing separate laboratory compaction tests, and thus can be employed in practice for preliminary design assessments and/or soil–TDA optimization studies.

Soil stiffness as a function of dry density and the degree of saturation for compaction control

A data set of the coefficient of vertical subgrade reaction for a plate diameter of 30 cm, KP.FWD, measured by Portable Falling Weight Deflectometer tests in full-scale compaction tests on sandy soil using various types of compaction machines was analysed. Based on this analysis and the previous analysis of a CBR data set from another full-scale compaction test series, a set of conclusions could be drawn. The soil stiffness indexes (SSIs), CBR and KP.FWD, can be expressed by, respectively, an empirical equation multiplying a function of ρd and another of Sr, where CBR and KP.FWD decrease significantly as Sr increases. As such, ρd values cannot be estimated from SSI alone. By fixing the field ρd – w compaction curve by keeping the soil type and the field compaction energy level, CELf, to those in the field compaction tests in which the SSI – ρd – Sr correlation has been calibrated, field compacted ρd &w states can be estimated by measuring the SSI values. Then, by the upper-bound and lower-bound control of SSI, the field compacted states approach the specified target, where, typically, ρd = the maximum dry density for CELf and Sr = the optimum degree of saturation, (Sr)opt. A method to incorporate this indirect but fast SSI-based compaction control into the conventional ρd &w-based compaction control is proposed.

Experimental and Statistical Study on Black Cotton Soil Modified with Cement–Iron Ore Tailings

The investigation focused on the response of black cotton soil (BCS) treated with mixtures of iron ore tailings (IOT) and cement to varying compaction effort (CE). Preliminary tests showed that the un-treated soil is A-7-6 (22) on the basis of AASHTO protocols of classification while the USCS (Unified Soil Classification System) guidelines placed the soil in CH group. Laboratory tests carried out included cation exchange capacity, CEC, Specific gravity (Gs) and compaction test. Three compaction energy levels (i.e., British Standard heavy (BSH), West African Standard (WAS) and British Standard light (BSL)) were adopted for the compaction test. Test results showed that CEC decreased; Gs and MDD increased while OMC also decreased for all cement contents considered when admixed with the different IOT contents up to 10 % IOT by the soil dry weight. MDD values of 1.58, 1.59, 1.62, 1.64, 1.64 and 1.66 Mg/m3 were noted for 1% cement and 0, 2, 4, 6, 8 and 10% IOT content compacted with BSL energy. Also, OMC values of 21.2, 20.8, 20.5, 20, 20.3 and 20.2% were noted for 1% cement and 0, 2, 4, 6, 8 and 10% IOT content compacted with BSL energy. Same trend was noted for higher cement concentrations and compactive efforts. Regression models for MDD and OMC, considered as dependent variables while C (cement content), CE, IOT, Gs and PF (percentage of fine) as independent variables were developed using software (Mini-tab R15). The result of regression analysis shows that the independent variables considered greatly influence the dependent variables. ANOVA (Analysis of variance) was use to establish the levels of contributions of cement and IOT to the improvements recorded. Therefore, black cotton soil optimally treated with 4% cement 10% IOT blend and compacted with BSH energy is recommended for soil remediation or geotechnical engineering applications. Keywords— Compaction effort, iron ore tailings, black cotton soil (BCS), Analysis of Variance, regression analysis.

HYDRAULIC CONDUCTIVITY CHARACTERISTICS OF A FINE-GRAINED SOIL POTENTIAL FOR LANDFILL LINER APPLICATION

Sanitary landfills (SLFs) are usually employed as final waste disposal facility to protect public health and the environment. As a result of rapid population growth and urbanization, there is currently a great demand to construct SLFs in the Philippines. The hydraulic conductivity characteristics of remolded samples of a locally abundant fine-grained soil compacted at different compaction energy level is investigated to determine the suitability of the soil as landfill liner material. The hydraulic conductivity of lining system is one very salient feature of the SLF to prevent contamination of nearby soil and water sources. The physical properties of the soil are determined through a series of laboratory tests which includes the grain-size distribution, specific gravity, Atterberg limits, soil classification, Cation Exchange Capacity (CEC), X-ray powder diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEMEDS). The falling head laboratory test was conducted to determine the saturated coefficient of hydraulic conductivity. A numerical model was formulated that can predict hydraulic conductivity as a function of the void ratio. The resulting coefficient of hydraulic conductivity ranges from 1.98 x 10-6to 1.0 x 10-7cm/sec meet the Philippine standard requirement. The soil being classified as clay loam can readily be used as top lining material. However, additional study on unconfined compressive strength and volumetric shrinkage among other parameters is recommended prior to use of the fine-grained soil as bottom lining material as soil amendment maybe necessary.

Effects of compaction and suction on the hydromechanical properties of a dam core clay

The paper presents an experimental study of the hydromechanical behavior of a compacted clay used in the design of the core of the Boughrara dam (western Algeria). The influence of compaction energy level (CEL) is explored using three different energies: Standard Proctor energy (SP), reduced Proctor energy (SP-20 blows) and enhanced Proctor energy (SP+ 20 blows). The resulting compaction curves are supplemented by measurements of suction, which is a very important parameter in the behavior of compacted unsaturated soils. In addition to the compaction curves, elastic modulus and immediate bearing capacity ratio (IBCR) are measured, and related to suction and compaction energy level (CEL). Mechanical compaction paths following the SP curve and drying-wetting paths starting from SPO are compared. Mechanical properties such as E-modulus and IBCR are related to the two independent major parameters γd and Sr. Measuring these mechanical properties in the field allows to evaluate the compaction state regardless of the CEL. The results are compared with those of the literature.

Experimental Investigation into the Impact of Compaction Energy Level on Thickness of Flexible Pavement

As a means of gaining a better understanding of the impact of compaction energy levels on the thickness of flexible pavements, this study investigated samples that were 50% thicker than the standard Marshall specimen sizes. The gradations for those longer (thicker) specimens were based on the binder course gradations as specified by the Republic of Turkey’s General Directorate of Highways. To obtain reliable assessments of the thicker specimens, we compared our test results with those of a control group consisting of standard Marshall Briquettes prepared using the same materials. All specimens were compacted with 10 different compaction energy levels that were increased by fives, starting from 50 blows and ending at 95 blows. After determining their lengths, volumes and specific gravities, a special marble cutter was used to split the thick specimens into two equal parts. Those two identical specimens were identified as the "thin specimens". Subsequently, the Marshall stability test and the indirect tensile test were applied both to the standard Marshall specimen group and the thick and the thin specimen groups. The test results showed that asphalt specimens of 47 and 95 mm in height were optimally compacted after being subjected to 65 and 70 blows.

COMPACTION CHARACTERISTICS OF A FINE-GRAINED SOIL POTENTIAL FOR LANDFILL LINER APPLICATION

Increasing population growth and urbanization results in increased demand for waste disposal processes and facilities that can protect public health and the environment. In the Philippines, there is a great demand to construct sanitary landfills (SLF) with only 387 local government units (LGUs) or equivalent to 23.86% compliant to date with Republic Act 9003 which mandates all LGUs to use the sanitary landfill. The compaction characteristics of a locally abundant fine-grained soil at different compaction energy levels were investigated as part of a broader study in the suitability of the soil as a landfill liner material. Compaction is essential in the preparation of a well-compacted soil liner in a sanitary landfill to avoid or minimize the migration of leachate and thereby reduce the risk of groundwater pollution. The physical properties are determined through a series of laboratory tests which covers the grain-size distribution, specific gravity, Atterberg limits, soil classification, XRD and SEM-EDX. Correlations to estimate the compaction characteristics at any rational compaction energy (E) are developed. The maximum dry unit weight values at different compactive efforts were used to determine void ratios which were then utilized to compute for the saturated hydraulic conductivity using numerical model for hydraulic conductivity for the same soil type. The resulting hydraulic conductivity ranges from 2.30 x 10-7 to 1.20 x 10-7 cm/sec well above the required value in the Philippines as per RA 9003 and its IRR for the intended Category I and II SLFs application