Search results

The present work focuses on evaluating the physical and mechanical characteristics of geopolymer concrete (GPC) by replacing the sodium silicate waste (SSW) in place of traditional river sand. The aim is to create eco-friendly concrete that mitigates the depletion of conventional river sand and conserves natural resources. Additionally, the study seeks to explore how the moisture content of filler materials affects the performance of GPC.

SSW obtained from the sodium silicate industry was used as filler material in the production of GPC, which was cured at ambient temperature. Instead of the typical conventional river sand, SSW was substituted at 25 and 50% of its weight. Three distinct moisture conditions were applied to both river sand and SSW. These conditions were classified as oven dry (OD), air dry (AD) and saturated surface dry (SSD).

As the proportion of SSW increased, there was a decrease in the slump of the GPC. The setting time was significantly affected by the higher percentage of SSW. The presence of angular-shaped SSW particles notably improved the compressive strength of GPC when replacing a portion of the river sand with SSW. When exposed to elevated temperatures, the performance of the GPC with SSW exhibited similar behavior to that of the mix containing conventional river sand, but it demonstrated a lower residual strength following exposure to elevated temperatures.

Exploring the possible utilization of SSW as a substitute for river sand in GPC, and its effects on the performance of the proposed mix. Analyzing, how varying moisture conditions affect the performance of GPC containing SSW. Evaluating the response of the GPC with SSW exposed to elevated temperatures in contrast to conventional river sand.

The purpose of this paper is to use the waste materials in soil stabilization and low traffic volume roads so as to minimize the cost of subgrades for road construction along with solving disposal problems of waste materials thus protecting the environment.

An extensive laboratory study has been carried out on various samples of soil alone and along with waste materials such as municipal solid waste incineration ash and marble dust by adding cement to evaluate their effect on geotechnical characteristics of clayey soils.

The experimental study revealed that mixture of soil:Municipal solid waste incineration ash (MSWIA):Cement and soil:Marble dust (MD):Cement can be successfully used for the construction of low traffic volume roads. The differential free swell of the clayey soil is nil on adding MSWIA: cement and MD: cement to clayey soil in optimum amounts.

The research needs further experimentation on combining both MSWIA and MD together to stabilize clayey soil.

The research can be successfully used by government agencies in subgrades of low traffic roads.

The utilization of waste materials in the study solved the disposal problem of both waste materials, thus protecting the environment and giving quality living standards to people.

The use of MSWIA along with cement and use of MD along with cement for evaluating geotechnical properties has not been studied in the past. The present study is focussed on the use of both these materials along with cement in soil stabilization.

Circular economy (CE) has gained the attention of the business community with the promise of several trillions of dollars to be gained from finding productive uses for waste materials, and developing new business models focused on extending and reimagining the useful life of products. Industrial symbiosis (IS) involves the shared management of resources among multiple firms, most often within some geographic proximity. IS is particularly focused on the reuse of secondary materials, such as industrial by-products, for which conventional recycling does not exist. IS and CE represent a radical reconceptualization of business models from individual to collective competitive advantage with private and public benefits. IS has been recognized as a novel strategy for businesses and regions interested in implementing the CE. In this chapter, we explore the conditions and circumstances in which IS could play a pivotal role in increasing circularity and sustainability in diverse supply networks.

The purpose of this paper is to examine the use of phragmites australis ash (PAA) in cementitious systems to achieve sustainable construction.

In this paper, the properties of mortar containing PAA as partial cement replacement are determined. The PAA is produced through slow burning in a closed system to minimize the CO₂ emission. A total of four mortar mixes are prepared with PAA replacement levels ranging from 0% to 30% by weight. The water to binder and the proportions of binder to sand are 0.55 and 1:3 by weight, respectively. The properties tested are density, compressive strength, flexural strength, ultrasonic pulse velocity, water absorption by total immersion and capillary rise. Testing is conducted at 1, 7, 28 and 90 days.

While there is a decrease in strength as the amount of PAA increases, there is strong indication of pozzolanic reaction in the presence of PAA. This is in agreement with the results reported by Salvo et al. (2015), where they found noticeable pozzolanic activities in the presence of straw ash, which is rich in SiO₂ and relatively high K₂O content. At 90 days of curing, there is a decrease of 5% in compressive strength at 10% PAA replacement. However, at 20% and 30% replacement, the reduction in compressive strength is 23% and 32%, respectively. The trend in flexural strength and ultrasonic pulse velocity is similar to that in compressive strength. The water absorption by total immersion and capillary rise tends to increase with increasing amounts of PAA in the mix. There seems to be a linear relationship between water absorption and compressive strength at each curing age.

The Phragmites australis plant used in this investigation is obtained from one location and this present a limitation as the type of soil may change the properties. Also one method of slow burning is used. Different burning methods may alter the composition of the PAA.

This outcome of this research will contribute towards sustainable development as it will make use of the waste generated, reduce the amount of energy-intensive cement used in construction and help generate local employment in the area where the Phragmites australis plant grows.

To the best knowledge of the authors, the ash from the Phragmites australis plant has not been used in cementitious system and this research can be considered original as it examines the properties of mortar containing PAA. Also, the process of burning in a closed system using this material.

Foundry produces cast metal components and parts for various industries and drives manufacturing excellence all over the world. Assuring quality of these components and parts is vital for the end product quality. The complexity in foundry operations increases with the complexity in designs, patterns and geometry and the quality parameters of the casting processes need to be monitored, evaluated and controlled to achieve expected quality levels.

The literature addresses quality improvement in foundry industry primarily focusing on surface roughness, mechanical properties, dimensional accuracy and defects in the cast parts and components which are often affected by numerous process variables. Primary data are collected from the experts working in sand and investment casting processes. The authors perform machine learning analysis of the data to model the quality parameters with appropriate process variables. Further, cluster analysis using k-means clustering method is performed to develop clusters of correlated process variables for sand and investment casting processes.

The authors identified primary process variables determining each quality parameter using machine learning approach. Quality parameters such as surface roughness, defects, mechanical properties and dimensional accuracy are represented by the identified sand-casting process variables accurately up to 83%, 83%, 100% and 83% and are represented by the identified investment-casting process variables accurately up to 100%, 67%, 67% and 100% respectively. Moreover, the prioritization of process variables in influencing the quality parameters is established which further helps the practitioners to monitor and control them within acceptable levels. Further the clusters of process variables help in analyzing their combined effect on quality parameters of casting products.

This study identified potential process variables and collected data from experts, researchers and practitioners on the effect of these on the quality aspects of cast products. While most of the previous studies focus on a very limited process variables for enhancing the quality characteristics of cast parts and components, this study represents each quality parameter as the function of influencing process variables which will enable the quality managers in Indian foundries to maintain capability and stability of casting processes. The models hence developed for both sand and investment casting for each quality parameter are validated with real life applications. Such studies are scarcely reported in the literature.

The purpose of this paper is to investigate the applicability of lean and green practices to foundry industry in India for improving productivity and eliminating waste, incorporating the sustainability into business performance measures.

The study used survey questionnaire method to collect data against 16 lean and green practices from 71 middle- to senior-level professionals belonging to Indian foundry industry. The survey instrument of lean and green practices was developed based on a number of sources from the literature and formal discussions with academicians and foundry industry professionals. The responses were received on a five-point Likert scale ranging from least applicable to most applicable. Exploratory factor and reliability analyses are conducted to obtain and validate constructs and measure each constructs Cronbach’s α (i.e. a consistency coefficient). The lean and green practices are categorized into the four constructs, namely, workplace organization practices, management practices, inventory control practices, and industrial manufacturing and quality improvement practices. Further, descriptive statistics is employed to find out the relative significance of lean and green practices.

Factor and reliability analyses show that all four constructs are adequate and reliable to illustrate lean and green practices. Descriptive statistics indicates that lean and green practices are applicable for implementation to a certain extent in the foundry industry. Correlation analysis shows that lean practices are positively and moderately interrelated with green practices. Thus, the results present a strong evidence that lean and green practices are moderately applicable for implementation in the foundry industry.

The paper provides insights into the applicability of lean and green practices implementation in the context of a developing country and presents evidence that lean and green practices are moderately applicable in the foundry industry. In addition, this paper is one of the few efforts to promote sustainable development within the industry.

The purpose of the paper is to illustrate an approach for developing a framework of indicators for integrating environmental protection into corporate performance. This paper also highlights Green Productivity Index (GPI) of the Continuous Improvement (CI) performed in a foundry casting, which includes both economic and environmental performances.

In the paper data were collected from a foundry and used for developing indicators and Green Productivity Index (GPI). Mass balance concept was used for quantification of environmental indicators.

The paper finds the approach adopted will provide a clear guidance for developing indicator and GPI to various types of industries. A casting case indicates that the GPI can be used as an actionable feedback for leadership to make effective decisions.

This research in this paper developed a framework of indicators for measuring direct environmental impact from the foundry, while indirect environmental impact due to electricity consumed has yet to be performed. Limited external validity of the indicator framework, as the analysis was performed in a single foundry.

The paper relies on a unique foundry data. Environmental indicators may vary, since the melting furnace used for melting metal and type of molding process used for making molds may vary from one foundry to another.

This paper is a holistic approach of combining theory and practical ideas to cover the scope of sustainable development. From a research perspective, it establishes a framework of indicators for the integration of environment into foundry and creates new research and application opportunities to other pollution‐intensive industries. From a practical perspective, the framework of indicators developed to this point provides a guideline of immediate applicability.

Recycling construction waste is a promising way towards sustainable development in construction. Recycled aggregate (RA) is obtained from demolished concrete structures, laboratory crushed concrete, concrete waste at a ready mix concrete plant and the concrete made from RA is known as RA concrete. The purpose of this study is to apply multiple linear regressions (MLRs) and artificial neural network (ANN) to predict the mechanical properties, such as compressive strength (CS), flexural strength (FS) and split tensile strength (STS) of concrete at the age of 28 days curing made completely from the recycled coarse aggregate (RCA).

MLR and ANN are used to develop a prediction model. The model was developed in the training phase by using data from a previously published research study and a developed model was further tested by obtaining data from laboratory experiments.

ANN shows more accuracy than MLR with an R²-value of more than 0.8 in the training phase and 0.9 in a testing phase. The high R²-value indicates strong relation between the actual and predicted values of mechanical properties of RCA concrete. These models will help construction professionals to save their time and cost in predicting the mechanical properties of RCA concrete at 28 days of curing.

ANN with rectified linear unit transfer function and backpropagation algorithm for training is used to develop a prediction model. The outcome of this study is the prediction model for CS, FS and STS of concrete at 28 days of curing.

Mutual Investigation. There seems to be a refreshing, open breeze blowing through the ranks of time and motion study technicians these days. Gone are the ponderous exponents of the mystic art and, instead, we find the experts vying with each other, almost, in telling their audiences how easy time and motion study really is if you only sit down and think about it.

The purpose of this research was to develop new sustainability indicators consistent with the sand mould casting industry, through benchmarking of cleaner production (CP), in order to identify the levels of practice and performance of companies of the casting sector. In addition, a lean manufacturing checklist was specified in order to verify the presence of lean manufacturing techniques employed to eliminate waste towards CP. No previous work was found in the literature that attempts to assess practices and performance of companies performing sand mould casting (a significantly polluting manufacturing process) in the context of CP and lean manufacturing.

For the application of this benchmarking, nine companies from the sand mould casting sector were studied, where the profile of each company was analysed through eight variables and 47 indicators. Data was obtained through face-to-face visits and questionnaire application in the companies, and the data was analysed both quantitatively and qualitatively.

The results obtained were the diagnosis of companies' practices and performance resulting from their position in the benchmarking charts, as well as the identification of the areas in which companies should implement improvements aiming at achieving CP.

This research was developed specifically for sand mould casting companies, and each process has its own characteristics

14 companies were invited to participate in this survey, but nine companies agreed to participate. Unfortunately, there were companies that declined to participate in the survey.

It is important to diagnose casting companies regarding CP practices, performance and deployment potential. Thus, important negative issues in the company can be identified, and with this information, they can develop actions focussed on cases that need more attention. In addition, this work contributes to evaluate the relationship and efficiency of improvement actions developed by companies in the context of both lean manufacturing and CP, aiming to reduce or eliminate the environmental impact. The improvement of practices and performance of a company regarding CP is considered to be beneficial to supply chain management in the context of sustainability, as the other participating companies are likely to seek ways to reduce environmental impact, and the diagnostics provided by this work may also be used by those companies.