Rubber/crete: mechanical properties of scrap to reuse tire-derived rubber in concrete. A review

The recycling of waste tires is of paramount importance for the environment protection and for economic reasons too. The amount of scrapped tires in USA reached 550 million tires per year and it is still raising. In the EU even higher numbers are estimated reaching the value of 1 billion tires per year. Disused tires are transformed into wastes, causing a highly negative environmental impact. Tire disposal mainly involves highly polluting treatments (e.g. combustion processes for the production of fuel oil), while only a small percentage of waste (from 3% to 15%) is destined for less invasive treatments such as powdering. In this work we will see some previous study in which waste tire powder of different ranges used in combination with cement concrete mixture, providing a final product with suitable mechanical properties for the chosen engineering application. As results of previous work recorded that reaching a good compressive strength can be achieved through replacing 30% of powder tire with crush sand. First, the percentage of aggregation between crumb rubber and crushed sand increases the compressive strength will drop extremely. Second, aggregation replacement between crumb rubber and crushed sand lower than 30 % can show reduction in density at around 10% leading lower in its weight. Third, modulus of elasticity depends on the percentage of addition, the more rubber added to concrete the lesser it will be. In addition to that, the lower the toughness of concrete means the higher strength. Moreover; addition of rubber to concrete increases the toughness value of it (1)

Reuse of tyre steel fibres as concrete reinforcement

To attain economically viable and environmentally friendly tyre recycling, it is necessary to develop new applications and products, which will use tyre by-products (especially the steel cord) as raw materials. The authors demonstrate that the steel fibres recovered from used tyres can be used to reinforce concrete elements. This application has a great potential, as it is estimated that more than 500000 t of high-quality steel fibres could be recovered annually from used tyres in the EU alone. This paper presents the work carried out as part of various ongoing projects on the use of steel fibres in concrete construction. The first part of the paper deals with waste management issues, the methods used to recover steel fibres from tyres, and existing applications of used tyres. The second part presents the mechanical behaviour of concrete elements reinforced with these steel fibres and discusses the relevant design and economic issues. It is concluded that the use of these steel fibres in concrete construction will benefit not only the construction industry, but also the producers and recyclers of used tyres

Haul Truck Tires Recycling

The disposal of large Off-the-Road (OTR) tires is an increasingly important concern. These tires can weigh up to 8,450 pounds with an overall diameter and width of approximately 140.7 inches and 45.1 inches respectively. OTR tires are used for mining vehicles such as haul trucks, wheel loaders, backhoes, graders, and trenchers.[1] These new tires cost between $38,000 and$50,000 each, depending on multiple factors including oil prices and the cyclical nature of the industry. Haul trucks contain six tires per vehicle, and mines replace these tires around every 9-12 months.[2] Statistics regarding discarded OTR tires are not provided by the industry as they are for other types of tires. Thus, it is difficult to approximate the number and location of waste OTR tires not only in individual states, but in the U.S. in general.[3] Currently, Minnesota and Arizona are the only states that place regulations and fees on OTR tires. However, Minnesota is the only state that actually tracks them.[3] The Rubber Manufacturers Association (RMA) roughly estimates that OTR tires account for 1% of scrap tires by number and 15% by weight. When the tires are replaced, the old tires can be discarded with the waste rock in stockpiles at the mining site but more often are landfilled without documentation by an appropriate agency due to lack of federal regulations. Their low density and hollow centers cause them to float to the top of landfills, disrupting the compactness.[4] Also, tires have a heat content 20-40% greater than that of coal which can be very dangerous on the rare occasions that tires catch fire in stockpiles.[5] Furthermore, burning tires release hazardous substances including pyrolytic oil, ash, and smoke, which contain carcinogens, heavy metals, and other toxic compounds.[6] Due to the large size of OTR tires, there are few facilities that can accommodate their recycling.[3] This leads to increased costs in transporting them to such sites. Transportation costs for a tire taken out of service can be up to $1000. In addition to the freight costs, recycling an OTR tire can cost up to$1500 because of their rugged construction compared to passenger tires which cost around 1 to recycle.[3] In response to the waste OTR tire problem, the Ball Hogs from the University of Arkansas have designed a solution that recycles OTR tires by using old tires as liners in ball mills for hard rock mines. Ball mills are large cylindrical vessels consisting of an outer shell, an inside liner and a load of metal balls. A motor turns the ball mill using a transmission system causing the metal balls to move in a cascading motion to grind the material fed into the ball mill. Ball mills require liners that are constructed from materials such as steel or rubber. For a 30 ft long ball mill with a Task #2 5 University of Arkansas 20 ft diameter, a hard rubber liner reinforced with steel can cost 150,000. These liners are replaced at least once a year, creating a substantial upkeep cost for these ball mills. Metal mines in Bolivia are already using tractor tires to line many ball mills. This technique has been effective for over twenty years. The high import costs of new liners and the low cost of labor has led many Bolivian metal processors to use truck and tractor tires as liners in their ball mills. This construction normally occurs on site using tools like handsaws, drills, torches and knives to cut up tires and manpower to mount these tire-made liners onto mills. However, this is not always the case in the U.S. where labor costs are much higher and the mills are generally larger. Many mines in the U.S. do not have the means to fabricate and install these liners on site; therefore, a third-party solution is proposed that will take a mine’s discarded tires and make ball mill liners out of them. The Ball Hogs’ solution provides an environmentally and economically feasible process of increasing the life of OTR tires beyond their typical use. This alternative would utilize the engineering and technology that makes these tires strong enough to hold a 400 ton truck. Mining companies would save yearly an average of $70,000 per ball mill liner replacement, and over 780,000 kg of CO2 per liner. Furthermore, mining companies would earn positive PR, goodwill, and tax breaks. We recommend all mining companies use their OTR tire treads as ball mill liners

Searching for the Profit in Pollution Prevention: Case Studies in the Corporate Evaluation of Environmental Opportunities

The concept of pollution prevention, or "P2," signifies a new, proactive environmental mindset that targets the causes, rather than the consequences, of polluting activity. While anecdotal evidence suggests that P2 opportunities exist and that many have been pursued, there is also the perception that the pace of P2 is far too slow. To explore that claim—and to shed light on barriers to P2 innovation—this paper presents case studies of industrial P2 projects that were in some way unsuccessful. While based on a very limited sample, the evidence contradicts the view that firms suffer from organizational weaknesses that make them unable to appreciate the financial benefits of P2 investments. Instead, the projects foundered because of significant unresolved technical difficulties, marketing challenges, and regulatory barriers. Based on evidence from the cases, the paper concludes with a discussion of environmental policy reforms likely to promote P2 innovation..

Analysis of Shipley Microposit Remover 1165 and AZ P4620 Photoresist waste disposal for Company XYZ

Includes bibliographical references

THE ENVIRONMENTAL APPROACH OF SLATINA CITY REGARDING WASTE MANAGEMENT

This article is focused both on a general description and the actual process ofwaste management in the area of Slatina city. After the conceptual presentation, causes andclasses of waste, the article develops and describes municipal and industrial waste aroundSlatina by also analyzing their temporal evolution. The main types of waste management aredescribed by highlighting their advantages and disadvantages along with the principles onwhich proper waste management is based. The conclusion regards the effect of applyingwaste management and justifies the choice of this specific urban area.waste, management, environment, Slatina.

The Link between Environmental Innovation, Patents, and Environmental Management

This paper analyses empirically the relationship between environmental innovations, environmental management and patenting. In particular it tests a number of propositions on how environmental management systems and the interaction with environmentally more or less concerned stakeholders are associated with the probability of firms to pursue innovation in general (measured as patenting behaviour) and specifically environmental innovation (measured as firm self-assessment and based on patent data). In applying a negative binomial as well as binary discrete choice models the relationship is studied using data on German manufacturing firms. As a novel and important insight, the study finds that environmental innovation can be meaningfully identified using patent data and that environmental innovation defined this way is less ubiquitous than self-reported environmental innovation. It also reveals that the implementation level of environmental management systems has a positive effect exclusively on environmental process innovation, whereas it is negatively associated with the level of a firm’s general patenting activities. For environmental product innovation and patented environmental innovations a positive relationship with environ-mentally concerned and a negative link with environmentally neutral stakeholders is found.Environmental innovations, patents

Path planning algorithm for a car like robot based on MILP method

This project is presents an algorithm for path planning optimal routes mobile robot “like a car” to a target in unknown environment. The proposed algorithm allows a mobile robot to navigate through static obstacles and finding the path in order to reach the target without collision. This algorithm provides the robot the possibility to move from the initial position to the final position (target). The proposed path finding strategy is to use mathematical programming techniques to find the optimal path between to state for mobile robot designed in unknown environment with stationary obstacles. Formulation of the basic problems is to have the vehicle moved from the initial dynamic state to a state without colliding with each other, while at the same time avoiding other stationary obstacles. It is shown that this problem can be rewritten as a linear program with mixed integer / linear constraints that account for the collision avoidance. This approach is that the path optimization can be easily solved using the CPLEX optimization software with AMPL interface / MATLAB. The final phases are the design and build coalitions of linear programs and binary constraints to avoid collision with obstacles by Integer Mixed Linear Program (MILP). The findings of this research have shown that the MILP method can be used in the path planning problem in terms of finding a safe and shortest path. This has been combined with collision avoidance constraints to form a mixed integer linear program, which can be solved by a commercial software package