Cement is still the most popular binder used in buildings construction. The volume of cement production in the world since 2013 has remained at the level of approximately 4.1 billion tons. The cement production process is energy intensive and is the world’s leading emitter of carbon dioxide. Therefore, the main activities cement plants are aimed at introducing technologies changes in production of clinkier (Edwards, 2019).The construction industry is responsible for the majority of CO2 emissions to the atmosphere: the industry emits 30% of total CO2, building emits 28%, transportation is responsible for 22% of CO2, the production of building materials causes 11% of CO2 emissions, including the cement industry is responsible for around 7% of emissions CO2. Other industries are responsible for around 9% of CO2 emissions to the atmosphere (Amran et al., 2020). The process of burning raw materials for the production of clinker is the most important stage of the entire cement production process (Mikulˇci´c et al., 2013; Andrew, 2019). Cement kiln dust (CKD) is waste generated during the production of clinker. The dust collected in the dust collectors is partly reused in the production process and some is stored. The storage method is not preferred due to its operations negative environmental impact. If the dust contains alkalis, chlorides, sulphates, or heavy metals, they cannot be recycled. Generally cement plants strive to reduce the formation of dust. About 1.5 tons of raw materials are used to produce 1 ton of clinker. After the extraction, grinding, and homogenization of rawmaterials, the process of calcination of calcium carbonate takes place.
Hakim S. Abdelgader(1-2022)

Abstract The stiffness modulus of asphalt in hot arid climatics was found to increase rapidly with pavement age and loading rate this reflects the rapid hardening and a complex change in the composition of the asphalt binder occurs due to high thermic susceptibility of the asphalt binder material in hot arid zones of sever climate.Besids this there is an increase in traffic heavier loads and higer tire pressures, the chemical composition of asphalt binders material and their rheological and visco-elastic properties also having a great role on the performance of these the asphalt binder material, a higer performance pavement requires asphalt that is less susceptible to high temprature ruttings or low temprature cracking and having sufficient bonding to stones aggregates. The durability of asphalt concrete is greatly influenced by the enviromental changes during the year between hot and cold tempratures and btween day and night high temprature can soften the asphalt making the mix more suscebtiple to rutting on the other hand low winter tempratures can increase the stiffness of asphalt reduce the flexibility of the asphalt concrete inducing fatique failure and serious cracks which adversly affects the pavement performanance the problem accetuated in hot arid site The loss of flexibility of the binder material will make the asphaltic mix susceptible to shrinkage cracking in the large temperature ranges that occur in these climates. For many years, researchers and development chemists have experimented with modified bitumen’s, of diffrent types . In the last thirty years many researchers have looked at a wide spectrum of modifying material Research continues in the quest to find materials that could enhance the properties of asphalt mixes thus enhancing pavement performance and reducing road maintenance costs. Addition of polymers has become common practice in several countries, with the main objective is improving flexibility and reducing thermal susceptibility of modified asphalt binders. There is growing interesting in asphalts modification with crumb rubber recycled from used tires, since this constitutes an important unique properties for asphalt improvement. The rubber used to produce tires comprises a mixture of different components, of valuable engineering characterstics, when crumb rubber is incorporated. The behavior of modified asphalt-rubbers depends on several factors, such as, the origin, fabrication process and grain size, the type of base conventional binder used in the mixture, temperature and time of the mixing process or digestion., a conventional base binder material having a penetration grade of 60/70 was mixed with rubber tires of (1-10 % by asphalt weight contents, was mixed for variable digestion times. The binder-rubber mixtures, produced using the wet process, were subjected to conventional tests, such as, penetration, softening point, Brookfield viscosity. The objective of the present work was to investigate the main characteristics of crumb rubber that affect the physical and the flow and the mehanical properties of modified binders. The results and findings from the study shows that the rubber additive can be added up to 5 % by asphalt weight did improvements in asphalt intrinsic characerstics
إبراهيم سعد ابودينة (2010)

Abstract Steel joints are the main part a steel structure. The steel members come together in a joint, to where the load action will be transferred between them.These members are with different section properties, may be joined with different type of connections welds, bolts or rivets. The level of fixity is also important which varies from flexible, semi-rigid to fixed. There is also an important factor of joint behavior, the type of loading (tension, shear, bending and torsion). For these the mentioned different factors that affects the behavior of a joint very complicated to demonstrate exactly.The design procedure according to the well known specification is generally based on experimental studies.The present study tries to throw light on some factors affecting the strength consideration for designing beam to columnconnection because of its importance in steel structures from point of view of uses.
علي عبدالله الجعط (2008)