11 resultados para PREVENTION OF ACCIDENTS AT WORK
em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States
Resumo:
The issue of corrosion of winter maintenance equipment is becoming of greater concern because of the increased use of liquid solutions of ice control chemicals, as opposed to their application in solid form. Being in liquid form, the ice control chemicals can more easily penetrate into the nooks and crannies on equipment and avoid being cleansed from the vehicle. Given this enhanced corrosive ability, methods must be found to minimize corrosion. The methods may include coatings, additives, cleansing techniques, other methods, and may also include doing nothing, and accepting a reduced equipment lifetime as a valid (perhaps) trade off with the enhanced benefits of using liquid ice control chemicals. In reality, some combination of these methods may prove to be optimal. Whatever solutions are selected, they must be relatively cheap and durable. The latter point is critical because of the environment in which maintenance trucks operate, in which scrapes, scratches and dents are facts of life. Protection methods that are not robust simply will not work. The purpose of this study is to determine how corrosion occurs on maintenance trucks, to find methods that would minimize the major corrosion mechanisms, and to
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The chemistry of today’s concrete mixture designs is complicated by many variables, including multiple sources of aggregate and cements and a plethora of sometimes incompatible mineral and chemical admixtures. Concrete paving has undergone significant changes in recent years as new materials have been introduced into concrete mixtures. Supplementary cementitious materials such as fly ash and ground granulated blast furnace slag are now regularly used. In addition, many new admixtures that were not even available a few years ago now have widespread usage. Adding to the complexity are construction variables such as weather, mix delivery times, finishing practices, and pavement opening schedules. Mixture materials, mix design, and pavement construction are not isolated steps in the concrete paving process. Each affects and is affected by the other in ways that determine overall pavement quality and long-term performance. Equipment and procedures commonly used to test concrete materials and concrete pavements have not changed in decades, leaving serious gaps in our ability to understand and control the factors that determine concrete durability. The concrete paving community needs tests that will adequately characterize the materials, predict interactions, and monitor the properties of the concrete.
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Report on the Local Public Health Services Grant administered by the Bureau of Local Public Health Services, a division of Health Promotion and Chronic Disease Prevention of the Iowa Department of Public Health for the period July 1, 2006 through June 30, 2008
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This report presents construction methods and results using three reinforcing fabrics to prevent reflection cracking in an asphalt overlay. The original highway in the rural area was Portland Cement Concrete 20 feet wide. It was widened by adding 2 feet of asphaltic concrete 10 inches deep on each side prior to resurfacing. Data are presented for the widening joint and transverse cracks in the rural area and for the random cracking in the urban area.
Resumo:
Mixture materials, mix design, and pavement construction are not isolated steps in the concrete paving process. Each affects the other in ways that determine overall pavement quality and long-term performance. However, equipment and procedures commonly used to test concrete materials and concrete pavements have not changed in decades, leaving gaps in our ability to understand and control the factors that determine concrete durability. The concrete paving community needs tests that will adequately characterize the materials, predict interactions, and monitor the properties of the concrete. The overall objectives of this study are (1) to evaluate conventional and new methods for testing concrete and concrete materials to prevent material and construction problems that could lead to premature concrete pavement distress and (2) to examine and refine a suite of tests that can accurately evaluate concrete pavement properties. The project included three phases. In Phase I, the research team contacted each of 16 participating states to gather information about concrete and concrete material tests. A preliminary suite of tests to ensure long-term pavement performance was developed. The tests were selected to provide useful and easy-to-interpret results that can be performed reasonably and routinely in terms of time, expertise, training, and cost. The tests examine concrete pavement properties in five focal areas critical to the long life and durability of concrete pavements: (1) workability, (2) strength development, (3) air system, (4) permeability, and (5) shrinkage. The tests were relevant at three stages in the concrete paving process: mix design, preconstruction verification, and construction quality control. In Phase II, the research team conducted field testing in each participating state to evaluate the preliminary suite of tests and demonstrate the testing technologies and procedures using local materials. A Mobile Concrete Research Lab was designed and equipped to facilitate the demonstrations. This report documents the results of the 16 state projects. Phase III refined and finalized lab and field tests based on state project test data. The results of the overall project are detailed herein. The final suite of tests is detailed in the accompanying testing guide.
Resumo:
Four series of five specimens each were investigated for static and fatigue strength. These four series differed in that there were two variables, the first being the subsidence of concrete around reinforcing bars and the second being shrinkage due to two different curing conditions. The combinations of these variables were then compared to each other by use of, load-deflection curves and S-H fatigue curves.
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To promote community care coordination and advanced care planning. Seamless communication and execution of individual patient care choices across the healthcare continuum.
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Young women in the juvenile justice system present with characteristics and experiences that differentiate them from their male counterparts. As such, the juvenile justice system in Iowa must consider these factors if it is to effectively and efficiently impact recidivism, rehabilitation and public safety. Data reveal the following trends: All youth in the juvenile justice system experience a significantly higher rate of child maltreatment than do youth in the general population. Additionally, young women have a distinctly higher percentage of reported sexual abuse. Young women commit primarily non-violent offenses, with shoplifting and running away being the only two areas where they exceed young men in number. Young women are held in detention for a substantially higher percentage of misdemeanor versus felony offenses than young men. Young women of color, particularly African American females, are far more likely to come into contact with the juvenile justice system. Additionally, arrests of minority females have increased during the same time frame as arrests of Caucasian females have decreased. The general type of offense committed by young women is against public order (i.e. alcohol related violations, disorderly conduct) or property (i.e. shoplifting), though young women with subsequent charges of a violent nature are likely to have had violent offenses initially as well. Historically, young women have been a smaller segment of the juvenile justice population. They remain so today. Consequently, they are easy to overlook. But Iowa’s response to them is no less important. Perhaps, because they are fewer in number, our system can have a true and meaningful influence, with prevention of further penetration into both the juvenile and adult systems being the ultimate goal. The Iowa Task Force on Young Women recommends the following measures to facilitate movement toward that goal: 1. Facilities and programs striving to provide the most effective and efficient services to young women will opt for single gender environments with female responsive programming that includes components to address trauma. 2. All institutions and agencies that work with females involved in the juvenile justice system and which receive state funding should be required to provide annual female responsive training to their employees. Training should be research based, progressive, ongoing and result in an implementation plan. 3. As detention reform proceeds, gender and the disproportionate number of females in detention for misdemeanor offenses must be an integral part of policy and decision making discussions including any recommendations for solutions to be implemented. 4. As research, data and planning progresses related to disproportionate minority contact with the juvenile system, the needs of girls of color be given equal consideration. Specifically, assessment tools must be without race/ethnic bias and they must also be female responsive.
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Incentive/disincentive clauses (I/D) are designed to award payments to contractors if they complete work ahead of schedule and to deduct payments if they exceed the completion time. A previously unanswered question is, “Did the costs of the actual work zone impacts that were avoided justify the incentives paid?” This report answers that question affirmatively based on an evaluation of 20 I/D projects in Missouri from 2008 to 2011. Road user costs (RUC) were used to quantify work zone impacts and included travel delays, vehicle operating costs, and crash costs. These were computed using work zone traffic conditions for partial-closure projects and detour volumes and routes for full-closure projects. Conditions during construction were compared to after construction. Crash costs were computed using Highway Safety Manual methodology. Safety Performance Functions produced annual crash frequencies that were translated into crash cost savings. In considering an average project, the percentage of RUC savings was around 13% of the total contract amount, or $444,389 of $3,464,620. The net RUC savings produced was around $7.2 million after subtracting the approximately $1.7 million paid in incentives. In other words, for every dollar paid in incentives, approximately 5.3 dollars of RUC savings resulted. I/D provisions were very successful in saving RUC for projects with full-closure, projects in urban areas, and emergency projects. Rural, non-emergency projects successfully saved RUC but not at the same level as other projects. The I/D contracts were also compared to all Missouri Department of Transportation contracts for the same time period. The results show that I/D projects had a higher on-time completion percentage and a higher number of bids per call than average projects. But I/D projects resulted in 4.52% higher deviation from programmed costs and possibly more changes made after the award. A survey of state transportation departments and contractors showed that both agreed to the same issues that affect the success of I/D contracts. Legal analysis suggests that liquidated damages is preferred to disincentives, since enforceability of disincentives may be an issue. Overall, in terms of work zone impact mitigation, I/D contracts are very effective at a relatively low cost.
Resumo:
Premature deterioration of concrete at the joints in concrete pavements and parking lots has been reported across the northern states. The distress is first observed as shadowing when microcracking near the joints traps water, later exhibiting as significant loss of material. Not all roadways are distressed, but the problem is common enough to warrant attention. The aim of the work being conducted under this and parallel contracts was to improve understanding of the mechanisms behind premature joint deterioration and, based on this understanding, develop training materials and guidance documents to help practitioners reduce the risk of further distress and provide guidelines for repair techniques. While work is still needed to understand all of the details of the mechanisms behind premature deterioration and prevention of further distress, the work in this report has contributed to advancing the state of knowledge.
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Improving safety at nighttime work zones is important because of the extra visibility concerns. The deployment of sequential lights is an innovative method for improving driver recognition of lane closures and work zone tapers. Sequential lights are wireless warning lights that flash in a sequence to clearly delineate the taper at work zones. The effectiveness of sequential lights was investigated using controlled field studies. Traffic parameters were collected at the same field site with and without the deployment of sequential lights. Three surrogate performance measures were used to determine the impact of sequential lights on safety. These measures were the speeds of approaching vehicles, the number of late taper merges and the locations where vehicles merged into open lane from the closed lane. In addition, an economic analysis was conducted to monetize the benefits and costs of deploying sequential lights at nighttime work zones. The results of this study indicates that sequential warning lights had a net positive effect in reducing the speeds of approaching vehicles, enhancing driver compliance, and preventing passenger cars, trucks and vehicles at rural work zones from late taper merges. Statistically significant decreases of 2.21 mph mean speed and 1 mph 85% speed resulted with sequential lights. The shift in the cumulative speed distributions to the left (i.e. speed decrease) was also found to be statistically significant using the Mann-Whitney and Kolmogorov-Smirnov tests. But a statistically significant increase of 0.91 mph in the speed standard deviation also resulted with sequential lights. With sequential lights, the percentage of vehicles that merged earlier increased from 53.49% to 65.36%. A benefit-cost ratio of around 5 or 10 resulted from this analysis of Missouri nighttime work zones and historical crash data. The two different benefitcost ratios reflect two different ways of computing labor costs.