The aim of this investigation, self-healing of cracks in concrete by using named Bacillus Subtilis bacteria isolated from agricultural soils and dry soil. Four concrete mixes include, one plain mix without bacteria, other mixes containing a different concentrations of bacteria 10 3, 106 and 109 cell/ml respectively were prepared. Hardened properties of concrete water absorption, ultrasonic plus velocity, and compressive strength at 7, 28, 60 and 90 days. Also concrete specimens applied to load 10% of compressive strength at 28 days were studied. The result indicate there is decrease in water absorption of (15-38)%, as well as the decrease in the concrete specimens of loading 10% of compressive strength of (23- 41%) relative to control concrete. Increase in compressive resistance of concretes specimens of (6- 20)%, (6-17)%, (8-22)% and (7-20)% for ages 7, 28, 60 and 90 days respectively, concrete specimens loaded by 10% of compressive strength, increased by (25-34%) and (34-39%) for 60 and 90 days relative to control concrete . It was observed that the UPV test of concrete specimens was increased. Scanning Electron Micrographic gave an increased in density, deposition of calcite carbonates in the voids and closure of the crack by precipitation of calcium carbonate layers was observed.
Permanent deformation (rutting Phenomena) of asphalt mixes is considered as one of the major forms of distress that affects the performance of flexible pavement structures. Many factors can cause permanent deformation to occur in asphalt mixtures, but aggregate gradation is one of the key factors responsible for this deterioration.
In this study, aggregate structure was designed using the Bailey method. Eight aggregate gradations were used to analyze their effect on rutting resistance of asphalt mixtures. Three additional mixes were then designed using Styrene Butadiene Styrene (SBS) as a modifier to improve the rutting resistance. Three percentages of SBS, namely (2 %, 4 % and 6 %) by weight of asphalt cement, were mixed for 60 min at a temperature of 180°C using a shear mixer with a rotation speed of 3000 rpm.
The asphalt mixtures were subjected to rutting test using a wheel tracking device at an air void level of 4% corresponding to optimum asphalt content. The results showed that the Bailey method maintained good resistance to permanent deformation as compared to conventional mixes. Overall, mixes with coarser gradation (Bailey Parameter, CACUW, greater than 95 %) and 4% SBS modified asphalt produced more resistance to rutting.
In recent works on the Internet of Vehicles, "intelligent" and "sustainable" have been the significant in the case of transportation. Maintaining sustainability is always a challenge. Sustainability can be achieved not only by the use of pollution-free vehicular systems, but also by maintenance of road traffic safety or prevention of accidents or collisions. Quantifying the sustainability of urban transport is important as evidenced by a growing number of studies to measure sustainability in transportation. This paper dealt with the challenge of measuring transport sustainability based on the long environmental and safety indicators. To overcome the issue of using too many indicators for evaluation, this paper develops a method for obtaining a composite transport sustainability index for limited sources and time for collecting data. Seven sustainability indicators relevant to urban transport which deal with environmental and social (safety) aspects were selected depending on available data. The indicators were integrated to environmental, social (safety) sub-indices and then to a composite index, in a way that overcomes the limitations on normalization, weighting and aggregation. It is an attempt to quantify transport sustainability for arterials streets within the Hilla network which provides information about current situation of urban transport in different parts of the city. The value of I CST (composite index of transport sustainability) for main arterials at Hilla city (as case study) equal to 0.648, 0.542 and 0.462 for 40 th , 60 th and 80 th streets respectively. The value I CST is the highest at 40th street (inner Hilla citythe best case) and the lowest at 80th street (outer Hilla the worst case).
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