No abstract

This paper presents a framework and analytical studies to evaluate the impacts of airport locations on the surrounding urban area and land uses. This work is based on reviewing the impacts of some international airports on land uses and compared them with those of Hurghada International Airport in Egypt. The description of land use surrounding Hurghada International Airport was obtained from the general strategic plan for Hurghada City in 2015-2027, prepared by the General Authority for Urban Planning (GAUP). Compatibility factors that were used for evaluating the development of land use around airports are generally presented, as well as the criteria of these factors. Two main compatibility factors were applied, namely noise and safety, but the safety factor was applied only from a land-use point of view. The results of the present study indicated that some land uses are incompatible with the noise factor as well as other uses are incompatible with the safety factor in terms of the type of land use. For unused areas, the permitted and prohibited uses are mentioned relative to the location of each area within its safety zone.

Recent SUPERPAVE technology allows assessment and performance grading (PG) of modified asphalts according to AASHTO T 350–14 and ASTM D7405-15 standards. These testing protocols use modified - multiple stress creep recovery (MSCR) test, to yield the high temperature PG and the traffic level of the asphalt binder. Latest AASHTO T 350–14 test protocol is used to assess two major Egyptian bitumen products, Alex and Suez (pen 60/70) before and after polymer modification. These standard products have different fractional composition since they are obtained from different local origins. Low density polyethylene modification (LDPE) of such products leads to a major enhancement in their PGs and decreases their high temperature rutting potential. A characteristic comparison between virgin a and LDPE modified bitumen samples is provided to achieve the desired PG and traffic level for high reliability projects deployed in Egyptian hot climate regions. it was found that a 2% wt recycled LDPE modification, enhances the high temperature performance grade and the traffic grade from PG 58S-XX to PG 64S-XX for the bitumen produced by Alexandria Oil Company, and from PG 58S-XX to PG 70S-XX for the bitumen produced by Suez Oil Company.

Most of road networks are constructed using hot mix asphalt (HMA). HMA is used for roads construction and maintenance at high temperature (150-170˚C) requiring high fuel consumption. In addition, gases emissions generated from HMA are issues of concern among the pavement researchers. Therefore, reducing gases emission and mixing temperature is an objective toward sustainable asphalt pavement industry. Thus, using warm or half-warm asphalt mixes as a modern technique are considered suitable alternatives to HMA. This study aims to reduce gasses emissions and manufacturing cost of HMA using half-warm mixes asphalt (HWMA). Chemical additives are used in order to produce HWMA at low temperature. In this study, Ethoxylated Nonyl Phenol (NP9) was used to enhance the performance of asphalt mixes at low temperature. The tried percentages of NP9 were 10, 15, 20, and 25% (by weight of bitumen). The tested mixes include control mix (mixed at 155°C) and modified mixes (mixed at 90°C, HWMA modified by NP9). Rolling thin film oven (RTFO), Marshall, moisture susceptibility, indirect tensile strength (ITS), wheel tracking, scanning electron microscopic (SEM) and gases measurements tests were carried out for control and modified mixes. The results indicated that, significant changes were occurred in modified mixes compared to the control mixes. Bitumen viscosity decreased by the increase of NP9 percentages. The optimum percentage of NP9 was 10% by weight of bitumen.The retained penetration of modified specimens by 10% NP9 was higher than conventional specimens by 40.26%. Also, the results showed that Marshall stability and Marshall Quotient (MQ) of HWMA enhanced by 15.22% and 11.58% respectively. Producing HWMA reduced the loss of stability by 18.10% and changed tensile strength ratio from 91% to 96% by an enhancement of 5.50% compared to the conventional mixes. In addition, the resistance of HWMA specimen against rutting was higher than or as same as the value of control specimen during the test period. From SEM test results, a significant change was observed for all tested specimens , the structure of control specimen under SEM was differ than the shape of modified specimens. Finally, the chemical analysis showed that the gases emissions reduced by manufacturing HWMA at 90C.

The small cracks in concrete constructions are inevitable due to deterioration during their service life throughout different load combination factors. In this study, we aimed to isolate, identify, and construct a bacterial consortium able to heal small cracks of concrete and enhance the different properties of concrete. Six isolates of bacillus, endospore-forming bacteria were isolated. There are only three isolates out of the six coded as NW-1, MK and NW-9 were showed the ability to produce urease enzyme and able to grow at 60°C with optimum growth at a temperature of 40°C. These isolates were survived in high pH, where isolate NW-1 was tolerated pH up to 11 with optimum growth at 10 while the isolates NW-9 and MK showed growth at pH 12 with an ideal growth at 10. CaCO3 production was observed by the three bacterial isolates whether in pure or mixed cultures (bacterial consortium) but the consortium consisting of MK and NW-9 was significantly the highest in productivity among them. Therefore, these two isolates were identified using 16s as Bacillus flexus MK-FYT-3 and Bacillus haynesii MK-NW-9 and deposited to GenBank under accession numbers MN965692 and MN965693 respectively. The effect of bacteria on some properties of concrete was studied, and the results showed that the compressive and tensile strengths of bio-concrete specimens were significantly increased by 31.29, 29 % after 7 days and 36.3, 39 % after 28 days of curing compared to control specimens. The results of permeability indicated that the bio-concrete specimens significantly showed less permeability than the control specimens by 21.1, 23.1% after 7 and 28 of curing, respectively. To determine the concrete density, Ultrasonic Pulse Velocity (UPV) test was performed, and the bio-concrete specimens gave higher values ​​than control specimens by 26 and 20% after curing for 7 and 28 days, respectively. Also, surface healing of concrete was observed visually, the bio-concrete showed white precipitates around and inside the cracks after 7 days, which led to almost complete sealing of concrete after 28 days of curing, while the control samples were showed only very slight deposits on the surface and away from the cracks. The micro-analysis of concrete samples using SEM and XRD were done. It was found that the bio-concrete specimens showed crystalline precipitate with different shapes under SEM, while no such deposits appeared in the control specimens. On the other hand, the XRD profile was explained the characteristic peaks of calcium carbonate in both the bio-concrete and the control specimens, but the peak intensity was higher in the bio-concrete than the control specimens. This reflects the effectiveness of bacterial consortium in repairing and preventing the concrete cracks from spreading in addition to improving the various properties of concrete leading to increasing its life and sustainability.