The reliable correlation model for intelligent compaction (IC) is to be developed by integrating characteristics of the filling material and control parameters of the vibratory roller. Key ...characteristics of the backfill soil from the construction site of Rongwu Highway are tested through the modified Proctor test and the direct shear test. A well-documented dataset is built by summarizing 4000 shear strengths from open literature and 246 data from laboratory tests in this study. The PSO-BP-NN model is developed based on this dataset to predict the shear strength and compactness of the subgrade soil in the scope of mechanical properties and compaction powers. The importance analysis of the input variables is performed with the Random Forest algorithm. The influence mechanism is analyzed in sequence. The plain soil and the lime soil demonstrate typical compaction curves, and the lime soil is less sensitive to the influence factors. An optimal compaction power exists for determining the optimal moisture content utilizing the shear strength, tending to be less conservative. The moisture content is the most important factor for the compactness, followed by the compaction power; the particle size is suggested to be considered for real-time evaluations. The compaction mechanism is mainly attributed to the water film theory and the electrochemical property of the filling soil. This study aims to provide a reliable model to estimate the compactness in the aspect of material properties so as to enhance the accuracy of the IC model.
Abstract
Reclaimed asphalt pavement (RAP) is one of the innovative and effective technologies in many places in the world. The utilization of RAP is rapidly increasing popularity and becoming an ...emerging technique in India. As per IRC-120:2015, removing or reprocessing pavement materials containing aggregates that are bitumen coated is termed as RAP. These materials are gained through a process in which the existing surface pavement is reclaimed and reused after processing for reconstruction, resurfacing, or repaving. Well graded and high-quality aggregate are achieved from this process. Proper utilization of RAP with specified properties and specified percentages, not only serve as an alternative useful pavement material but also helps in reducing the usage of natural construction material, that will directly reduce the overall cost of projects. By conducting tests as per MoRTH specifications (5th Revision), the various characteristics of RAP material and fresh aggregates are observed. The main objective of the study is to carry out the performance tests: Modified Proctor test on fresh material as well as on material mixed with reclaimed asphalt pavement i.e. 10%, 20%, and 30% of total mix and to achieve optimum moisture content and maximum dry density by using Modified Proctor Test. Attempts are carried out to design a new pavement using Indian Road Congress (I.R.C-37:2018) guidelines and utilization of RAP material. Economic benefits are calculated in terms of fresh and RAP (10%, 20%, and 30%) mix material pavement.
The California Bearing Ratio (CBR) and modified proctor parameters belong to the soil geotechnical properties used to assess soil behavior. Direct measurement of these properties can be quite ...time-consuming in large-scale applications or when immediate results are required. Therefore, significant research efforts have been made in the literature to develop indirect methods for their estimation. However, some gaps in the state-of-the-art can be highlighted in these topics, such as the deficiency in computational models to calculate the maximum dry unit weight (γd(max)), optimum moisture content (wopt) and CBR, and the lack of methods that consider their intrinsic influence on each other. Hence, in this investigation, mathematical and computational models were created to obtain the above-mentioned variables from the soil grain size distribution. The mathematical model was based on Multiple Linear Regression (MLR) correlations. Meanwhile, the computational model was constructed from a custom-made Deep Neural Networks (DNNs) architecture. Subsequently, the accuracy of these models was validated with an experimental case study. The results demonstrated that the proposed methods in this study are more precise than previous approaches in the literature. Accordingly, the main contribution of this manuscript to the industry is the formation of models with high exactness to predict the γd(max), wopt and CBR of granular soils.
•The grain size distribution was used to forecast several soil parameters.•Mathematical models were created to predict the γd(max), wopt, and CBR.•An ANNs architecture was designed to estimate various soil parameters accurately.
Currently, the scarcity of natural resources has been a significant impact on the construction industry. The demand for fresh aggregate becoming huge due to the increase in the construction of ...pavement and fulfilling the aggregate requirement is a great concern. In this research, an effort has been shaped to assess the feasibility of the use of Reclaimed Asphalt Pavement (RAP) material for improving the strength properties of the granular sub-base (GSB) layer. RAP aggregate was partially and fully replaced with fresh aggregate in different percentages to test various strength properties. Efforts were being made to improve the strength of the GSB layer by using RAP concerning soaked California Bearing Ratio (CBR) by blending with natural aggregates (NA). To know the best of mix proportions, RAP was partially and fully replaced with virgin aggregate in varying percentages such as 0%, 25%, 35%, 45%, 55%, 65%, and 75%. Modified compaction tests were performed on 100 % RAP and mixtures containing various percentages of RAP to establish the optimum water content for CBR sample preparation. Soaked CBR value was determined at 7 days, 14 days to see the effect of RAP on the GSB mixes. It was observed from the results that the soaked CBR value of RAP improves from 32% over 100% when it is mixed with natural aggregates in varying percentages and made it appropriate for utilizing it as a sub-base of flexible pavement. Depending upon the experimental outcomes, it was deduced that RAP in the sub-base layer is limited to 55% which has exquisite properties as natural aggregates utilized in the road sub-base.
The landslides or slope failures are responsible for many fatalities and significant delays in travel by blocking the roads. The soil properties such as cohesiveness, angle of internal friction, and ...bulk unit weight are the primary parameters responsible for land stability and should be considered for the analysis. In this paper, a Xanthan Gum (XG) biopolymer is applied to the laterite soil to improve its engineering properties. The Plaxis Limit Equilibrium (LE) 2D software is utilized to analyze the slope's stability. Four section/ paths of the Lote Parshuram Ghat in the Ratnagiri area of Maharashtra, India are taken for the analysis. It is observed that the application of the XG to the soil which is exposed to atmosphere (normal condition) and submerged conditions improves the strength of the soil and stability of slopes. When compared to conventional laterite soil in its natural state, the cohesiveness of soil treated with XG at concentrations ranging from 1 to 5% is greatly improved, increasing from 250.51% to 378.64%. XG-treated laterite soil has a maximum dry density of 1.72 gm/cc, 28.36% higher than untreated soil. Submerged XG-treated soil often shows a factor of safety (FOS) improvement of across 57.25%. The slope stability analysis revealed that the optimum percentage of xanthan gum as a stabilizer for the submerged slope condition is 2.7% that increase the factor of safety. In case of normal condition, the factor of safety (FOS) and strength of the laterite soil increases with the reinforced percentage of xanthan gum.
It is well known that three quarters of the world contain saline water. The saline water contains amounts of salt dissolved in water to a concentration of parts in per millions (ppm) includes sodium ...chloride, Sodium sulfate and magnesium sulfate. Compaction of Base coarse layer is usually done by water which is considered tap water. Cites near shores often need coastal roads to act as service roads parallel to shore lines. For this matter, the use of saline water in compaction is considered a main objective in this situation due to the decrease in transportation cost of Tap water used in hauling and compaction of base coarse layer. This research studies the effect of saline water on the mechanical properties of the unbounded granular material used in base coarse layer. The study compares the results between the use of saline water and standard tap water by subjecting both samples to different lab tests such as California baring ratio (CBR) and modified proctor. The results showed that saline water could be used successfully in the operation of constructing base coarse layer with good results concerning the amount of absorbed water content and maximum dry density of the base coarse layer which will result in good compaction. In addition, the CBR test results showed high evaluation of strength for samples contained saline water. The study used Dolomite material for base coarse layer from Jabal Ataqa as one of the most used aggregate types in Egypt through construction.
With the increasing population, the limited natural sources are decreasing and environmental pollution is increasing. In recent years, the increase in industrial wastes and the high cost of disposal ...methods of these wastes have necessitated the evaluation of industrial wastes in industrials businesses. Truck tires, blast furnace slag, fly ash, waste concrete, and dismantled asphalt coverings can be listed as industrial wastes. If these wastes are used, environmental pollution is reduced, and contributions are made to the country’s economy. In this study, an evaluation of marble waste as base material was performed. In this scope of work, physical tests, a modified Proctor test, a dry/wet California bearing ratio test, and density of soil in place by the sand cone test were conducted. Also, X-ray diffraction, X-ray fluorescence, and mercury intrusion porosimetry analyses were performed on these marble waste. As a result, the physical and mechanical properties of marble waste were determined. In conclusion, marble waste has been found suitable as a base material according to the Technical Specifications of Turkish Highways.
Purpose
Industrial wastes such as copper slag and fly ash are being generated in tons every year and disposed mainly by land fillings, resulting in wastage of useful land. Copper slag in itself is a ...granular cohesionless sand-like material, while fly ash is highly pozzolanic. The purpose of this paper is to investigate copper slag and fly ash mixes with cement as stabilizer for their proper use in road construction.
Design/methodology/approach
Different trial mixes of copper slag and fly ash were tested for obtaining the optimum mix having maximum dry density. Cylindrical specimens were prepared using optimum mix with different proportion of cement (3, 6 and 9 per cent) and cured for period of 7, 14 and 28 days in desiccator. Several tests such as proctor test, unconfined compressive strength test, splitting tensile strength test and soaked CBR test were carried out.
Findings
After analyzing the variation of test results with varying cement content and curing period, maximum compressive strength of 10 MPa and maximum tensile strength of 1.5 MPa was found for specimen having 9 per cent cement content cured for a period of 28 days. It was concluded that copper slag and fly ash when mixed in optimum proportion and stabilized with 6 and 9 per cent cement can be effectively used as granular material in sub base and base layer of road pavement.
Originality/value
A typical flexible pavement section was designed and checked using IITPAVE software which gave desired results. This paper may add value in the areas of pavement design, waste utilization, etc.
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