Study Effects of Gradation and Material Thermal Property of Chip Seal Aggregates in Roller Concrete Pavement Crack Healing by Image Processing and RMS.

One of the most roller cement concrete pavement failures of pavement is the formation of first cracks. The roughness of its completed surface after the installation has restricted the usage of this pavement. Therefore, engineers increase the quality of service of this pavement by placing a layer of asphalt coating; The primary goal of this study is to evaluate the impact of particle size and type of chip seal aggregates on filling cracks in rolled concrete pavement. Accordingly, rolled concrete samples with chip seal covering were prepared with various aggregates (limestone, steel slag, and copper slag). Then, the influence of temperature on its self-healing ability was tested by putting the samples in the microwave device for cracking improvements. With the aid of Design Expert Software and image processing, the Response Surface Method reviewed the data analysis. Even though due to the study's limitations, a constant mixing design was applied, the results of this study indicate that the amount of crack filling and repair in specimens slag is higher than that of aggregate materials. With the increase of steel and copper slag, 50% of repair and crack repair at 30 °C, the temperature is 27.13% and 28.79%, respectively, and at 60 °C, the temperature is 58.7% and 59.4%, respectively.

Setting research priorities to achieve long-term national road safety goals in Iran.

Background: Road traffic crashes (RTCs) and its associated injuries are one of the most important public health problems in the world. In Iran, RTCs rank second in terms of mortality. To address this issue, there is a need for research-based interventions. Prioritizing researches using a variety of approaches and frameworks to determine the most effective interventions is a key nodal point in the RTCs' research policy planning cycle. Thus, this study aims to generate and prioritize research questions in the field of RTCs in Iran. Methods: By adapting the Child Health and Nutrition Research Initiative (CHNRI) method, this study engaged 25 prominent Iranian academic leaders having role in setting Iran's long-term road safety goals, a group of research funders, and policymakers. The experts' proposed research questions were independently scored on a set of criteria: feasibility, impact on health, impact on the economy, capacity building, and equity. Following the prioritization of Research Questions (RQs), they were all classified using the 5 Pillar frameworks. Results: In total, 145 Research Questions were systematically scored by experts against five criteria. Iran's top 20 road traffic safety priorities were established. The RQs related to "road safety management" and "road and infrastructure" achieved a high frequency. Conclusions: The top 20 research questions in the area of RTCs in Iran were determined by experts. The majority of these RQs were related to "road safety management". The results of this study may contribute to the optimal use of resources in achieving long-term goals in the prevention and control of road traffic crashes and its related injuries. Considering these RQs as research investment options will improve the current status of Road Traffic Injuries (RTIs) at a national level and further advance toward compliance with international goals. If these research priorities are addressed, and their findings are implemented, we can anticipate a significant reduction in the number of crashes, injuries, and deaths.

Effect of oil pollution on function of sandy soils in protected deserts and investigation of their improvement guidelines (case study: Kalmand area, Iran).

Soil pollution is one of the most dangerous sorts of environmental pollutions because of waste materials, fossil fuels, etc. Unfortunately in developing countries, there are very few arrangements to prevent soil pollution due to the fossil fuels and to improve polluted soil. In this research, influences of gas oil on properties of Kalmand protected area's sandy soil near Yazd, Iran, were studied. It was found that gas oil constituted 5.25% of soil weight in the refueling station in the region. Therefore, cleaning and strengthening of the soil by adding cement rather than expensive and complicated methods were the most important goals of this research. First, the influence of gas oil on soil properties was studied, and to improve the soil, different percentages of ordinary portland cement were added to the polluted sand to study the improved soil properties using laboratory tests. It was found that unconfined compressive strength, cohesion, and angle of internal friction of sample with 16% cement and 8% gas oil after 28 days of curing were higher than those of the specimen of 6% cement and 14% gas oil, at 4.6, 5.4, and 1.3 times, respectively. Moreover, based on falling head tests it was observed that permeability of the stabilized specimens decreased substantially. From SEM tests, fewer voids were observed in the stabilized samples, which led to less pollutant penetration into the soil. According to EDX, although dangerous elements in the contaminated specimen made up 3.99% of the specimen total weight, addition of cement introduced considerable amounts of elements that are vital for pozzolanic reactions. Therefore, it can be concluded that addition of cement to the gas oil-polluted soil not only can improve geotechnical properties of the soil and reduce its permeability, but also is very efficient for environmental issues.