Effect of length of steel fibers of waste tires on splitting tensile strength of concrete

The increase in volume of vehicles ultimately increases the number of waste tires. The proper disposal or reutilization of waste tires is a challenge. This study is aimed to utilize the steel fibers of waste tires as reinforcement in concrete. Concrete cylinders were cast with addition of different percentages of steel fibers (0-2%) and length (10-20 mm). The fresh and hard properties of concrete reinforced with different percentages of steel fibers and lengths were observed. It is seen that splitting tensile strength of concrete increased with increase in the length of fiber and with the increase in the percentage of fiber. The inclusion of the fibers in concrete causes the reduction in the workability of concrete

Factors That Influence Travelers’ Willingness to Adopt Bus Rapid Transit (Green Line) Service in Karachi

peer reviewedBus rapid transit (BRT) system is a sustainable mode choice alternative and traffic management method for traffic congestion problems in urban areas. As an extent of total demand management, BRT has broadly been implemented in many countries. BRT has proven to be progressive in alleviating traffic congestion and the difficulty of finding parking spaces in city centers. Currently, people driving their automobiles to work cause traffic congestion along Karachi’s main corridors. People cannot be persuaded to use public transit until their travel patterns are understood. Therefore, the disparity between public and private transportation must be addressed. This research aimed to develop a model to shift car travelers toward Karachi’s Green Line BRT and investigate the factors that influence car travelers’ decisions. A questionnaire-based survey was carried out on single-occupant vehicle (SOV) users in the Green Line corridor of Karachi. This study investigated the elements that influence SOV users’ willingness to adopt the BRT system and studied the possible ways of attracting car drivers to BRT. Data were examined using descriptive-analytic techniques such as the contingency table approach in conjunction with a Chi-square test of the independence/association model in SPSS. Furthermore, binary logistic regression was applied to the highly mediated associated variables. The research’s outcomes were geared at the imposition of parking fees at workplaces to deter individuals from parking their automobiles there. SOV travelers can be diverted to BRT services using this strategy. The research findings will assist policymakers and serve as a foundation for scientific investigations on the travel demand model for the BRT system.11. Sustainable cities and communitie

Modelling travellers' choice of information sources and of mode

This study investigates the travellers' choice of information sources and their subsequent mode choice decisions. The goal of this study is to develop a comprehensive choice model that can capture the information acquisition process by predicting the choice of information sources together with its effects on modal choices of the travellers. A decision making framework for travel information acquisition is developed and the abstract terms, necessary to be tested in the models, are identified. A Stated Preference experiment is developed based on the complicated decision making process and an interactive CATI questionnaire is designed to cope with it. Utility functions are formulated by expanding travellers' choice set to include different combinations of the viable sources of information and with the inclusion of policy sensitive variables. The research employs a wide range of modelling methodologies and examines a range of traditional and newly developed calibration and estimation procedures including Mixed Logit models with individual specific parameters and the newly developed Random Regret Minimisation framework. The study also analyses the effects of travel planning websites on travel decisions and establishes a link between content, design, advertisements, and presentation of information on overall modal shift. The results indicate that travellers give credence to government owned sources and give more importance to their own previous experiences followed by multimodal websites, train websites, friends and coach websites respectively. A website with less search time, specific infonnation on users' own criteria, and real time information is regarded as most attractive by the travellers. The study also found that the market share of the modes increases when information sources show decreased travel time and cost values and the maximum results are achieved when different information sources give the same information to the travellers. These results show that information sources could be used to influence the mode choice of the travellers

Modelling Choice of Information Sources

This paper addresses the significance of traveller information sources including mono-modal and multimodal websites for travel decisions. The research follows a decision paradigm developed earlier, involving an information acquisition process for travel choices, and identifies the abstract characteristics of new information sources that deserve further investigation (e.g. by incorporating these in models and studying their significance in model estimation). A Stated Preference experiment is developed and the utility functions are formulated by expanding the travellers' choice set to include different combinations of sources of information. In order to study the underlying choice mechanisms, the resulting variables are examined in models based on different behavioural strategies, including utility maximisation and minimising the regret associated with the foregone alternatives. This research confirmed that RRM (Random Regret Minimisation) Theory can fruitfully be used and can provide important insights for behavioural studies. The study also analyses the properties of travel planning websites and establishes a link between travel choices and the content, provenance, design, presence of advertisements, and presentation of information. The results indicate that travellers give particular credence to governmentowned sources and put more importance on their own previous experiences than on any other single source of information. Information from multimodal websites is more influential than that on train-only websites. This in turn is more influential than information from friends, while information from coachonly websites is the least influential. A website with less search time, specific information on users' own criteria, and real time information is regarded as most attractiv

Heavy Metal Diffusion through Soft Clay under High Hydraulic Gradients

This study was focused on the determination of contaminant transport parameters of heavy metal Zinc moving through saturated soft Bangkok undisturbed clay under high hydraulic gradients. These parameters were compared with contaminant transport determined under concentration gradient alone (pure diffusion). In total fifteen column tests were conducted and a mathematical model was applied to determine the coefficients. Two different source concentrations conditions, constant and decreasing, were applied. Testing periods were ranged from 15-60 days while hydraulic gradients were ranged from 0-500. The curves between relative concentration and time and pore volume were developed for the constant source condition whereas curves between source reservoirs concentrations and time were developed for decreasing source condition. The effective diffusion and distribution coefficients, De and Kd, were determined by curve fitting using the computer code POLLUTE v 6.3. The results showed that diffusion coefficient increases and distribution coefficient decreases as hydraulic gradient increases from 0 to high value of 500 due to contribution of dispersion and additional molecular diffusion at high advective velocity. Thus, testing at high gradients ensures the safe performance of earthen barriers under worse conditions

A Conditioned Model for Choice of Mode Under Information

This paper examines the influence of time and cost information obtained from different sources on choice of mode of Leeds' long distance travellers. The choice of mode was investigated through modal attributes provided by at least two different information sources which might provide contrary or corroborating information rather than on actual attributes. The experiment included telephone administered questionnaire including RP (Revealed Preference) questions and an SP (Stated Preference) exercise dealing with the choice of modes conditioned by the information received from various sources. Information on travel time and cost was provided from two different information sources for each mode to facilitate the conditioning of mode choice on corroborating/contradictory information. The research employs a wide range of modelling methodologies and examines a range of traditional and newly developed calibration and estimation procedures including Mixed Logit models with individual specific parameters and the newly developed RRM (Random Regret Minimisation) framework. The study confirms that the market share of the modes increases when information sources show decreased travel time and cost values and shows that the maximum shares are achieved when different information sources give the same information to the travellers. The study found that pre-trip time information has more influence on mode choice when derived from websites than when derived from other sources. Pre-trip information on costs was, however, less influential when derived from websites than when derived from other sources

Numerical Analysis of Shallow Foundations with Varying Loading and Soil Conditions

The load–deformation relationship under the footing is essential for foundation design. Shallow foundations are subjected to changes in hydrological conditions such as rainfall and drought, affecting their saturation level and conditions. The actual load–settlement response for design and reconstructions is determined experimentally, numerically, or utilizing both approaches. Ssettlement computation is performed through large-scale physical modeling or extensive laboratory testing. It is expensive, labor intensive, and time consuming. This study is carried out to determine the effect of different saturation degrees and loading conditions on settlement shallow foundations using numerical modeling in Plaxis 2D, Bentley Systems, Exton, Pennsylvania, US. Plastic was used for dry soil calculation, while fully coupled flow deformation was used for partially saturated soil. Pore pressure and deformation changes were computed in fully coupled deformation. The Mohr–Columb model was used in the simulation, and model parameters were calculated from experimental results. The study results show that the degree of saturation is more critical to soil settlement than loading conditions. When a 200 KPa load was applied at the center of the footing, settlement was recored as 28.81 mm, which was less than 42.96 mm in the case of the full-depth shale layer; therefore, settlement was reduced by 30% in the underlying limestone rock layer. Regarding settlement under various degrees of saturation (DOS), settlment is increased by an increased degree of saturation, which increases pore pressure and decreases the shear strength of the soil. Settlement was observed as 0.69 mm at 0% saturation, 1.93 mm at 40% saturation, 2.21 mm at 50% saturation, 2.77 mm at 70% saturation, and 2.84 mm at 90% saturation of soil