Experts have given much attention on the use of waste in asphalt paving because of its significance from a sustainability perspective. This paper evaluated the performance properties of asphalt concrete mixes modified with Crumb Rubber (CR) as a partial replacement for two grade sizes of fine aggregate (2.36, and 0.3 mm) at six replacement rates: 0%, 2%, 4%, 6%, 8%, and 10% by weight. Asphalt concrete mixes were prepared at their Optimum Asphalt Content (OAC) and then tested for their engineering properties. Marshall properties, fatigue, rutting, ideal CT index test, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray (EDX) spectroscopy were deployed to examine the crystalline structure and elemental composition of the CR-modified and unmodified asphalt concrete mixtures. The results showed a difference in Marshall's characteristics. The CT index revealed that the optimum cracking tolerance was achieved with a 2% CR substitution. Wheel track test results indicated that a 4% CR addition improved the rutting resistance of the asphalt mixture. SEM and EDX analyses exhibited significant changes in microstructure and elemental composition with the addition of CR. The main findings reveal that the use of 2% CR as a partial replacement of fine aggregate contributes to the production of more durable asphalt concrete mixtures with better serviceability. However, these results are based on laboratory experiments and require field verification to ensure practical applicability and long-term performance.
The study of Stress- Strain relation for novolac reinforced by qujurate plant was carried out before and after the immersing in boiled water at 100C0 . It was found that the compression strength and surface hardness decreased when the composites immersed in boiled water for long times.
Abstract:
The Iraqi economy faces complex economic challenges that threaten the prospects for growth and stability in the short and medium term, The decrease in oil revenues on which Iraq is based in financing its total expenditure, both operational and investment, led to the emergence of a deficit in the government budget, As the global oil price crisis affected the revenues of the Iraqi government negatively, especially as this negative impact coincided with the increase in military spending resulting from Iraq's war against terrorism, Which led to the Iraqi government to implement austerity measures were to reduce public spending on several projects, which are less important compared to projects that a
... Show MoreHigh tunnels, or unheated plastic greenhouses, are becoming increasingly popular among organic vegetable growers across the United States. However, the intensive production typical of these systems presents soil health challenges, including salinization due to high fertilizer or compost inputs coupled with lack of rainfall to leach salts. Legume cover crops may improve soil health in high tunnels by reducing the need for external inputs, while adding organic matter. We tested the soil health effects of a winter hairy vetch (Vicia villosa Roth) cover crop used to replace fertilizer N in an organic tomato cropping system in high tunnels. Studies were replicated across three sites differing in climate and soil type (Kansas, Kentucky, and Minne
... Show MoreWe focus on studying the dynamics of bulk semiconductor optical amplifiers and their effects on the saturation region for short pulse that differ, however there is the same unsaturated gain for both dynamics. Parameters like current injection, fast dynamics present by carrier heating (CH), and spectra hole burning (SHB) are studied for regions that occur a response to certain dynamics. The behavior of the saturation region is found to be responsible for phenomena such as recovery time and chirp for the pulse under study.
Three types of metal carboxylates (Ho,Tb and Dy) stearates were LLSed as thennal stabi lizers for PVC. Infrared spectra (1500-1900
|
cm.1
were studied for PVC films stabilized with these metal
carboxylatcs. Two types of oxygen were round -containing products that were formed during the thermal degradation .On the other hand , the presence &nb
... Show MoreIn the resent years, there is a robust scientific interest in discovery of new anti-septic and anti-oxidant naturally products with no/or limited side effects. The current study aimed to investigate the protective role of the quercetin on inflammations induced by lipopolysaccharide (LPS) in male mice A number of criteria included i.e. liver and spleen index and IL-6 and IL1-β cytokines level in spleen homogenate were considered. Sixty male mice (8-9 week age) was divided into six groups and treated for 5 days as the following: the first group represented control, the second and third group were injected with 5, 10 mg/kg b.w doses of quercetin respectively. While the fourth and fifth groups were co-treatment with (5, 10 mg/kg b.w.) intraper
... Show MoreThe c.orrosion rate of low carbon steel in 4M hydrochlwic acid with and without presence of thiourea has b.een studied by gravimetric ahd gasometric methods over the temperature range 303-333 K.
The percentage protection of steel increases vvith the decrease of thimuea concentrations at various temperature range 303-333 K and
approaching highest protection (86.82%) at 303K by using I X 1 o-4 M
of thiourea. The high concentration .of thiourea ( lxlo-3 M), enl1ances.
the corrosion rates and act as dcpolariser for the hydrogen evolution
reaction,&n
... Show MoreBackground: Alum has been used as a treatment medication in cases of oral and gingival ulcers, and also as antiseptic mouthwash. This study aimed to examine the effects of different concentrations of Alum on inhibition zone, viability counts and adherence ability of Mutans streptococci compared with deionized water and chlorhexidine gluconate in vitro. Materials and methods: The study dealt with an in vitro study to establish a concentration of Alum mouthrinse that would have the minimum inhibitory concentration and minimum bacteriocidal concentration. The second part evaluated the anti-adherence ability of the experimental agents. Results: This study found that the antibacterial effect of Alum increases with its concentration from 50 to 1
... Show MoreWatermelon is known to be infested by multiple insect pests both simultaneously and in sequence. Interactions by pests have been shown to have positive or negative, additive or non additive, compensatory or over compensatory effects on yields. Hardly has this sort of relationship been defined for watermelon vis-à-vis insect herbivores. A 2-year, 2-season (4 trials) field experiments were laid in the Research Farm of Federal University Wukari, to investigate the interactive effects of key insect pests of watermelon on fruit yield of Watermelon in 2016 and 2017 using natural infestations. The relationship between the dominant insect pests and fruit yield were determined by correlation (r) and linear regression (simple and multiple) analys
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