Utilizing Employee Stress to Establish Guidelines for Managing Personnel During Lean Transition

Employee resistance has been one of the many primary obstacles during Lean execution. Employee stress is a principal outcome of resistance when implementing Lean systems. This research is directed towards finding the relationship between employee stress and Lean. The hypothesis states-Lean implementation increases employee stress. The research methodology involves investigating employee stress during various phases of Lean. This research proposes three phases of Lean that are- Lean Introduction Phase, Lean Implementation Phase, and Lean Refinement Phase. Surveys are used to collect data for the study. Two questionnaires are used 1) Lean Environment Evaluation Profile (LEEP) 2) Work Stress Profile (WSP). A pilot test is conducted using these two questionnaires. The results from the pilot test are used to calculate the sample size; the standard deviation was 13.06, with an acceptable confidence level of 95% and maximum error of 3. The sample size was calculated to be 72.80 rounded up to 73. A standard data collection procedure is designed to ensure consistency of data collection throughout the study, which included identifying the companies for the study. Hypothesis testing, correlation analysis, regression analysis, and descriptive and graphical analysis are used to analyze the data collected. Correlation analysis and regression analysis indicates that there is a negative correlation between employee stress and Lean. There is a - 0.531 correlation between employee stress and Lean. The coefficient of determination (r2) is calculated to be 0.28. The following regression equation was obtained from the analysis, Employee stress = 190 - (0.396) x (Lean) Hypothesis testing resulted in refuting the null hypothesis that was H0 = Lean increases employee stress. The results from data analysis indicated that as Lean progressed through various phases the employee stress reduced, however there is a slight increase in employee stress at the beginning of every phase as shown in figure 10. The research made the following conclusions based on the analysis of the data collected using the LEEP and WSP questionnaires. 1. There is a negative correlation between employee stress and Lean 2. Employee stress is different in the three phases of Lean 3. Various Lean principles have a different impact on employee stress in various phases of Lean This research identified areas for future research and suggested the following hypothesis: Human aspects of Lean are more stressful than technical aspects of Lean

Application of Epoxy-Asphalt Composite in Asphalt Paving Industry: A Review with Emphasis on Physicochemical Properties and Pavement Performances

One of the failure mechanisms associated with asphalt paving layers, especially on steel deck bridges, is large permanent deformation, which adversely affects its long-term performance in service. Thus, epoxy resin was introduced in asphalt paving industry to tackle permanent deformation of asphalt mixtures due to its thermosetting nature. In this review, epoxy resin as a dominant component of the epoxy-asphalt composite system was first considered, followed by a discussion on its curing methods and curing mechanism. Furthermore, the physicochemical property and mechanical performance of epoxy asphalt and epoxy asphalt mixture were thoroughly examined. Crosslink density of epoxy asphalt dictates its viscosity and thus the allowable construction time. Phase separation and dispersion of asphalt particles in the epoxy matrix was observed for epoxy-asphalt composite, and it showed superior elastic behavior and deformation resistance capability when compared with conventional asphalt materials. Furthermore, epoxy asphalt mixture exhibited significantly higher compressive strength, much better rutting resistance, and superior durability and water resistance properties. However, its low-temperature cracking resistance was slightly compromised

Utilization of Iron Ore Mines Waste as Civil Construction Material through Geopolymer Reactions

In India, due to fast pace development there is a drastic growth in the iron and steel industry. As of 2017, India is one of the largest producers of crude steel in the world. This has led to drastic increase in mining activity. Mining activity is responsible for generation of wastes, which can pose threat to the environment and its habitants. However, there is also a great potential for mines wastes to be utilized in construction industry, which can become an important ingredient for sustainable and eco-friendly development. In iron and steel industry, Iron ore tailings (IOT) and slimes utilization is still an area of challenge, because of the low content of iron oxide present in them, which is unsuitable for metal extraction. Usually particle size of slimes below 1 mm is not amenable for further metal extraction through conventional pelletization techniques. In the present study waste from two different iron ore mines have been tried for their utilization as a construction material through geopolymerisation technology. As a primary consideration, shapes made in the form of common bricks were tested for their densification behavior, compressive strength and water absorption. To reduce the cost, industrial wastes like fly ash, ground granulated blast furnace slag, and lime were tried in different batch compositions in addition to sodium silicate and sodium hydroxide. Relationship between compressive strength values with individual ratio of silica to alumina (Si/Al), silica to alumina with iron combined (Si/Al + Fe), and calcium to silica (Ca/Si) were developed. Based on the elemental ratios, critical threshold values were established that showed significant effect on the compressive strength of the final composite

A preliminary characterisation of innovative semi-flexible composite pavement comprising geopolymer grout and reclaimed asphalt planings

This article considers semi-flexible composite (SFC) pavement materials made with reclaimed asphalt planings (RAP) and geopolymer cement-based grouts. Geopolymer grouts were developed and used to fill the internal void structure of coarse RAP skeletons with varying levels of porosity. The geopolymer grouts were formulated at ambient temperature using industrial by-products to offer economic and environmental savings relative to conventional Portland cement-based grouting systems. They were characterised on flowability, setting time, and compressive strength. The effect of grout and RAP on SFC material performance was evaluated using permeable porosity, compressive strength, and ultrasonic pulse velocity. SFC performance was significantly influenced by both grout type and RAP content. Improved performance was associated with mixtures of high-flowability/high-strength grout and low RAP content. A practical limitation was identified for combination of grout with low-flowability/fast-setting time and well-compacted RAP skeletons. Solids content exceeding 49% by volume was not feasible, owing to inadequate grout penetration. A suite of SFC materials was produced offering performance levels for a range of practical pavement applications. Preliminary relationships enabling prediction of SFC elastic modulus based on strength and/or ultrasonic pulse velocity test data are given. A pavement design is given using SFC as a sub-base layer for an industrial hardstanding

Effect of hooked end steel fibers on strength and durability properties of ambient cured geopolymer concrete

Growing carbon emissions in the construction industry have warranted the use of alternative materials such as geopolymer concrete. At the same time exposure of concrete material to harsh environmental conditions has compelled to design of durable geopolymer concrete. The use of hooked-end steel fibers in conventional fiber-reinforced concrete has proven to improve its crack resistance, and thus, positively influence the durability properties of concrete structures. Nevertheless, limited studies explore the effect of hooked-end steel fibers on the strength and durability properties of ambient cured geopolymer concrete with a low NaOH content (i.e., 8 M concentration). In this study, ambient cured geopolymer concrete was prepared by fly ash, ground granulated blast furnace slag (GGBS), NaOH, Na2SiO3, manufactured sand, and natural coarse aggregates. Additionally, hooked-end steel fibers with an aspect ratio of 67 were added to the mix by volume fraction in dosages of 0 %, 0.5 %, 1 %, 1.5 %, and 2 %. The experimental results showed that the addition of fibers reduced the workability with a minimum slump of 70 mm and a maximum Vee Bee time of 8 s for mixes with 2 % steel fibers. The addition of fibers improved the compressive strength, split tensile strength, and flexural strength of geopolymer concrete, with a maximum strength of 41.44 MPa, 4.28 MPa, and 5.23 MPa at an optimum fiber dose of 1 %, respectively. Above the optimum dose, the strength of the steel fiber-reinforced geopolymer concrete (SFRGPC) was reduced. The depth of water penetration reduced in SFRGPC when compared to GPC. Moreover, the resistance to chloride ion penetration was not significantly affected by addition of steel fibers till optimum dose of 1 %. The scanning electron microscopic results revealed the positive effect of steel fibers in restricting the progression of cracks. This has resulted in smaller crack width in the SFRGPC when compared to GPC. Overall, steel fibers in optimum dose have improved the performance of geopolymer concrete and this will contribute towards low carbon material

In-plant production of bricks containing waste foundry sand—A study with Belgaum foundry industry

The main objective of this study is to utilize waste foundry sand (WFS) from Belgaum foundry industry in manufacturing of bricks. The process involved production of bricks in a fully functioning brick manufacturing plant, which has a production capacity of approximately 50000 bricks per month. The entire process of combining clay-sand mixtures, forming of bricks, drying and firing was done with local conditions. With minimum process it was possible to introduce upto 50% WFS in clay bodies to produce bricks of desirable properties. The minimum average wet compression resistance of 3.3 Mpa, and maximum average water absorption of 21.6% was obtained for bricks containing 50% WFS, when fired at 900 °C. There was insignificant difference in apparent porosity, water absorption, and specific gravity of bricks containing WFS, when compared to commercial bricks. The addition of WFS reduced the bulk density of the bricks, which has also caused reduction in compressive strength. WFS bricks can be classified as class III bricks, based on recommendations of IS 1077 standard specification. These bricks can be used in single storied load bearing structures, and also in the construction of infill walls in multi-storied framed structures. The structure, composition, and morphology of the raw materials, as well as bricks were studied by XRD, XPS, and SEM, respectively. Keywords: WFS, Porosity, Compressive strength, Bulk density, Specific gravity, XP

Strength and durability properties of geopolymer paver blocks made with fly ash and brick kiln rice husk ash

In India the generation of agro waste rice husk ash is abundant. The utilization of rice husk ash in development of geopolymer binders can be suitable to alleviate the environmental problems associated with disposal of rice husk ash. Further, the utilization of rice husk ash generated from the stacks of brick kilns has not been addressed in past, particularly in development of geopolymer binders. This study proposes development of geopolymer paver (GEOPAV) blocks utilizing brick kiln rice husk ash (BKRHA). It presents fresh, mechanical and durability properties of GEOPAV blocks blended with fly ash, BKRHA, natural aggregates, NaOH and Na2SiO3 solution, and cured in both sundry and room temperature conditions. Microstructural analysis using scanning electron microscope (SEM) and X-ray diffraction (XRD) was adopted to study the influence of BKRHA on hardened properties of GEOPAV blocks. The results show that addition of BKRHA reduce the workability of GEOPAV mixes due to micro porous surface with honeycombed structure of BKRHA particles. The addition of BKRHA showed negligible improvement in compressive strength of GEOPAV blocks. However, the major advantage was observed with improved split tensile strength and flexural strength for GEOPAV blocks with BKRHA. Further, the durability properties in terms of resistance to acid and frost attack was significantly improved with the addition of BKRHA in GEOPAV blocks. Such improvements can be attributed to high amounts of amorphous silica in BKRHA which contribute towards dissolution and formation of polymeric gel, and thereby serve as a binder to enhance the geopolymer matrix making it dense. Finally, all the developed GEOPAV blocks satisfy the IS 15658–2021 specification requirements and perform much better when compared to commercially available paver blocks

Geopolymer concrete paving blocks made with Recycled Asphalt Pavement (RAP) aggregates towards sustainable urban mobility development

Policy makers in India have realized the importance of facility for pedestrians and non- motorized vehicles in an urban infrastructure setup. This has resulted in increased utilization of construction materials like Portland cement and crushed stone, which are not environmentally friendly and sustainable. The current study presents the development of paver blocks for pedestrian facility using different wastes. Geopolymer concrete was synthesized by fly ash and recycled asphalt pavement aggregates for making of paver blocks. Paver blocks were produced in laboratory with recycled asphalt pavement aggregate replacement levels of 0%, 20%, 40%, 60% and 80% by weight of virgin coarse and fine aggregates. The developed paver blocks were tested for dimensions and tolerances, water absorption, compressive strength and abrasion resistance as per IS15658:2006 standard. The results of the laboratory study show that recycled asphalt pavement aggregates can be introduced into geopolymer matrix to produce paver blocks of desirable quality. Furthermore, its use in pedestrian facilities provides a new avenue for managing the excessive waste, which otherwise goes in landfills, incurring loss to the paving industry. Therefore, the proposed method can help decision makers to effectively utilize recycled asphalt pavement in paving industry with environment-friendly approach