Journal of Civil and Environmental Engineering

Roads are backbones for one’s country economy and play great role in public’s mobility. To make these well function proper drainage systems must have; and these drainages are major causes for land degradation and gully formation. This assessment was conducted in selected road drainage (bridges, culverts and side channels) of Mekelle to Adigrat 113 Km road. The study focuses types, causes, impact of road drainage erosion, and government attentions to protect erosions and possible remedial measures by selecting 60 farmers which are 26.67% of the total population in the study area (225) randomly downstream of the road; 17 DAs selected based on their profession of 4 Woreda experts. Major findings from the socioeconomic assessment using interviewing and field survey are 1) There are three types of erosions (splash and sheet, rill, and gully) but most common is gullying in 87 culverts (44.39%) 2) Major causes of gully from interview of experts are: 38.81% lack of conservation works upstream and downstream of the structure, 14.93% design problem and lack of appropriate energy dissipaters, 20.90% improper land use practices.

Water is playing a vital role and widely used in our life. The use of water for fire extinction and extinguishment is widespread because of the following reasons. The first is economic. A second reason is that many fire safety. Fire suppression by using water mist is widely considered to be an alternative to gaseous fire suppression agents. A lot of commercial activity has occurred in the last years to develop technology for fire suppression systems based on water mist. The objective of this paper is to investigate the effectiveness of water mist with various droplet sizes and various nozzle flow rate on fire suppression in hanger, taking into account extinguishing time, gas concentration, and temperature decay. Three nozzle flow rate with the same conditions were employed and different droplet size provided. It was found that the extinguishing time decreases with the droplet size decrease and flow rate increase. The temperature decay rate was improved by decreasing the droplet diameter or increasing the flow rate. In addition, with an increase in the extinguishing time, the concentration of O2 decreased while CO2 increased. The study is carried out using Fire dynamic simulator (FDS) combined with PYROSIM and SMOKEVIEW programs. These programs, to achieve the model of compartment fire scenario require investigating and determining temperature and gas concentration.

One of the legacies of the past in industrialized countries is that land has been contaminated due to mining, industry and society disposing of waste with little regard for future consequences. Contamination of the soil layers forms one of the major topics of Environmental Geo-technology. The accidental spillage or leakage of highly aggressive industrial effluents has detrimental effects on the properties of soil. The addition of these effluents in to the subsoil directly affects the use and stability of the supported structure. In the present day Geotechnical engineering, little consideration has been given to the potential influence of physico-chemical interactions on the mechanical performance of soil confronted with increasing occurrence of soil contamination. The modern construction requires a detailed study of the foundation material as well as its working during the course of lifetime of the structure supported by it. In this study, an experimental investigation is done to quantify the influence of contamination in two different types of locally available soils i.e. sand (SP) and clay (CL-ML), so as to understand the engineering behaviour of the soil under the effect of pollutants. Therefore, due to the multitude of these pollutants the study was restricted to the contaminant fluid, Petrol. Through this study it has been found that, the contamination of soil with petrol has a significant influence on the engineering behaviour of the soil and the consequent change in the engineering properties of the soil has been reported in this paper.

Precisely, researches have been done on Fiber Reinforcement Self-Compacting Concrete (FRSCC) which can divide into two different fields, material serviceability and mechanical rheology investigations. The mechanical aspect of FRSCC has been investigated to provide the constitutive models of shear and flexure capacity, tensile or compressive zone data. The characteristics of FRC are determined by post-cracking behavior and FRSCC is controlled by SCC workability. By using FRSCC the costs and construction period reduce significantly and its ability to place irregular section in terms of congestion of stirrups and bars and thin section is another great aspect. Consequently of this capability is to arrest cracks, fibers mixtures increased tensile strength, both at ultimate and at first crack, especially under flexural loading. The other ability of fibers are to hold matrix after extensive cracking. The transition failure from brittle to ductile by fibers is another ability of fibers which can absorb energy and survive under impact loading. In this study, investigate the fibers influence by two techniques, direct and inverse technique.

Global climate change attributed by CO2 emissions could seriously impact people’s daily lives. According to the statistics, road transport is one of the largest contributors to greenhouse gases. Simultaneously, the increasing number of vehicles, especially vehicle mileages traveled, will continue to induce more CO2 emissions. It is believed that the driving behavior is one of the most important factors that impact the CO2 emissions. However, some other factors may also contribute to the CO2 emissions, for instance, the geometric elements of a roadway. This paper explores the relationship between the horizontal curve radius and CO2 emissions on freeways from field tests under realworld driving conditions through the development of an Emission Factor Model (EFM). The prediction results were also compared with the measured CO2 emissions based on the default emission rates generated from Motor Vehicle Emission Simulator (MOVES). The modeling results indicate that the EFM has better performance for the estimation of CO2 emissions factors for horizontal curves on freeways under free flow conditions with a predicting error of 5.5%, which is much smaller than the one from a method directly estimated from MOVES (16.8%).

To reduce the energy consumption and CO2 emissions during asphalt production, several environmentally friendly technologies have been developed during the last years. One of these technologies is the cold recycling by using foamed bitumen. Foaming the bitumen reduces the binder viscosity temporarily and increases the volume as well. Homogenous foams are produced by injection of cold water into hot bitumen. The paper presents the results of laboratory testing of the physical and mechanical parameters of the recycled mixes using the foamed bitumen and resistance to the action of water. The aim of the tests was to evaluate the properties of the mixes in terms of the RAP Content and Foam Binder Content. To evaluate the significance of impact of both factors i.e., Foam Binder Content and RAP Content on the distribution of the analyzed parameters, two-way Analysis of Variance (ANOVA) was performed. ANOVA Analysis results suggest that the RAP in cold mixes is not completely acting as black rock implying that some portion of the residual aged binder is possibly rejuvenated or softened by adding new binders.

Roller-Compacted Concrete (RCC) started in the US and Canada near 30 years ago, at that time it was a new method to construct gravity dams or rehabilitated. After passing these years, it’s become one of the popular methods in designing dams and called Roller Compacted Concrete. No slump is the specific property of the concrete of RCC dams. This type of dam needs place concrete in thin layers and compacted by roller to meet the require compaction. By one side, RCC dams can dissipate energy by stair step slope more than 70 percent of water energy and from the other side, all of the ordinary dams need to have an emergency spillway, but due to using all the length of the crest for spillway in the RCC dams, it is removed and the cost of constructing decreased. One of the most common problems which occur in the RCC dams at the beginning of its usage is hairline cracks throughout dam. This kind of cracks can start from upstream to the downstream. Rehabilitations have got several options depends on the kind of cracks and situation of cracks on dams such as drill holes, injecting grout, using different type of membrane and geomembrane, covered sealing system and covered geomembrane content. In this paper, try to investigate the different rehabilitation way of RCC in detailed and specified the best way for each kind of cracks.

Surface water samples have been collected from various streams of SW Kashmir and analyzed for major ions and trace elements to determine the mechanisms controlling the surface water chemistry and suitability of water for drinking, domestic and irrigation purposes. The order of cations is Ca > Mg > Na > K and anions is HCO3 > Cl > SO4 > NO3. As per the Gibb’s diagram, the major ion chemistry of surface water is controlled by rock-water interaction. The evolution of surface water into Ca-Mg-HCO3 water type of Piper trilinear plot is due to easy dissolution of carbonate minerals and less time for water-rock interaction. Surface water samples are characterized by one main trend of Ca-Mg-HCO3 i.e., carbonate dissolution of Langelier-Ludwig diagram. The major ions and trace elements in the water samples are well below the standards prescribed by WHO and BIS for drinking purposes. Based on EC and TDS classification, the water is fresh, good for irrigation and desirable for drinking purposes. The water samples fall between soft to hard categories of hardness classification with 16.66% belonging to soft, 50% to moderately hard and 33.33% to hard categories. The suitability of water for irrigation was evaluated based on the quality parameters and plots of water like Magnesium Content, Sodium Percent, Wilcox diagram, US Salinity hazard plot and Doneen’s plot. According to the values of these parameters the surface water of the study area was found suitable for irrigation and the water can be used for irrigating most of the crops and majority of the soils.

Ramp metering is a proven, effective measure to deal with congestion and accidents. The most comprehensive study ever conducted on ramp metering was published in 2001 and evaluated their effectiveness by turning off the meters in the Minneapolis-St. Paul area . Without meters, freeway travel times increased 22% resulting in 2.6 million hours of unexpected delay.