To avoid the generation of air-entraining vortices at a projected outlet structure in an existing reservoir of a pumped-storage plant, large-scale model tests were conducted. The model, with a scale of 1:18, had the considerable dimensions of 30 m in length and 16 m in width. Due to the complex shape of the reservoir, the many inlets and outlets, and numerous operating conditions, very complex ...

This research is focused on the utilization of cable waste originating during recycling wires as a partial substitution natural aggregate in cement screed. The main goal work performed was to find an optimal level terms freezing–thawing resistance, which significant aspect for such type concrete mixtures. studied artificial gradually dosed screed by 5% volume up 30% substitution. influence also...

Among human activities, motor vehicles play the most important role in air pollution. Air pollution has negative impacts on people and on the environment. In this paper the effect of oxygen-enriched air (20.8%, 21.8%, 22.8%, 23.8% and 24.8%) and different bioethanol-gasoline blends (zero, 5%, 10%, 15%, 20% and 25%) in different engine speeds (1000 rpm, 2000 rpm and 3000 rpm) on the amount o...

among human activities, motor vehicles play the most important role in air pollution. air pollution has negative impacts on people and on the environment. in this paper the effect of oxygen-enriched air (20.8%, 21.8%, 22.8%, 23.8% and 24.8%) and different bioethanol-gasoline blends (zero, 5%, 10%, 15%, 20% and 25%) in different engine speeds (1000 rpm, 2000 rpm and 3000 rpm) on the amount of po...

Abstract Nowadays, the use of waste materials in concrete production is crucial for a clean environment and less cost. This study aimed to enhance some mechanical properties utilizing integral waterproof (IWP) admixture using ceramics as fine aggregate with finer particles improve compressive strength modulus elasticity absorption studied. Studies indicate increase by IWP only also reduction ce...

This article uses 1,4-dibromobutane, hexadecyl primary amine, sodium 3-chloro-2-hydroxypropionate, formaldehyde and formic acid as raw materials to synthesize a new type of concrete air entraining agent (1,4)-bis(cetylmethyl hydroxy-propionic quaternary ammonium salt) butane through the reaction ammonia alkylation quaternization. The characterizes molecular architecture product, surface activit...

The characterisation of recycled fine mortars under frost action was highlighted in this study. Mortars with three different ratios cement (RC), namely (10%, 30% and 50%) along a reference mortar 0% RC were prepared subjected to freeze–thaw (F–T) cycles without air-entraining agents. After 96 F–T cycles, the specimens did not reveal any macroscopic damage; however, changes noticed at microscopi...

Abstract The paper investigates the fresh and hardened mechanical properties of a concrete mix produced with partial or full substitution natural aggregates recycled from demolition works crushed tested cubes laboratory. Recycled aggregate (RAC) is that has been made waste materials as coarse and/or fine aggregate. One taken demolished buildings in Iraq due to military operations on 2014 other ...

Overview In free-surface flows the turbulence in the liquid may be sufficient to disturb the surface to the point of entraining air into the flow. This process is important, for example, in water treatment where air is needed to sustain microorganisms for water purification and in rivers and streams for sustaining a healthy fish population. Air entrainment is typically engineered into spillways...