The provision of openings in serviceable reinforced concrete beams may result in a substantial decline in the beam's capacity and integrity, indicating the necessity of opening strengthening. The present study investigates the experimental response of reinforced concrete T-beams with multiple web-strengthened openings disposed in shear span to static and impact loads. Fourteen RC T-beams were tested in two groups, each of seven beams. The first group was tested under static loading up to failure, while the second group was tested under repeated impact loading until the width of shear cracks reached 0.3 mm. The residual static strengths of the beams subjected to impact loading were then determined. The test variables considered were

Static loads exposing to mechanical components can cause cracks, which are lead to form stress concentration regions causing the failure of structure. Generally, from 80% to 90% of structure failure is due to initiation of the cracks. Therefore, it is necessary to repair the crack and reduce its effect on the structure where the effect of the crack is modelled as an additional flexibility to the structure. In the last few years, piezoelectric materials have been considered as one of the most favourable repairing techniques. The piezoelectric material converts the applied voltage on it to a bending moment to counter the bending moment caused by the external load on the beam at the crack location. In this study, the design of the piez

This Investigation aims to study the effect of adding Steel fibers with different volume fractions Vf (o.5, 0.75, and 1% by volume of concrete) with aspect ratio 100 on mechanical properties of concrete, and also
finding the influence of petroleum products (Kerosene and Diesel) on mechanical properties of Steel Fiber Reinforced Concrete (SFRC).
The experimental work consists of two groups: group one consists of specimens (cubes and prisms) plain and concrete reinforced with steel fiber exposed to continuous curing with water. Group two consists of
specimens (cubes and prisms) plain and concrete reinforced with steel fiber exposed to kerosene and diesel after curing them in water for 28 days before exposure. The results of all te

The peculiarity of the theater does not lie in its dramatic content because many literary genres and other artistic styles share with it in this content. The peculiarity of the theater lies in contemplating the drama through what is architectural, and this architectural axis is what distinguishes its character. It is a spatial poetry which is composed by the laws of physics and chemistry, (Weight, height, distance, rhythm, gravity, impulses and chemical excretions). i.e., what cannot be expressed in words. This is a game of space to exchange and organize energy and communicate in space by the living body, which contains the possibilities of the living drawing in space: in the time and place. This research deals with the importance of the

In this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate) on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m³ of Ca(OH)₂ and 2 and 3 kg/m³ of Na₂CO₃ were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were comp

Polymers have the ability to extract water after they have been added to the mortar or concrete mixture. They provide the absorbed water during hydration functioning as internal water source. Absorption polymers can absorb up to hundred times of their own weight of pure water.This research deals with the use of water absorption polymer balls in concrete and study the volumetric change of these mixes and compared the results with reference mix (without polymers). Samples were cured both in air and in water for the mixes to compare results which show that samples in air behave for expansion while sample in water acted for shrinkage.

The aim of this article is to study the dynamical behavior of an eco-epidemiological model. A prey-predator model comprising infectious disease in prey species and stage structure in predator species is suggested and studied. Presumed that the prey species growing logistically in the absence of predator and the ferocity process happened by Lotka-Volterra functional response. The existence, uniqueness, and boundedness of the solution of the model are investigated. The stability constraints of all equilibrium points are determined. The constraints of persistence of the model are established. The local bifurcation near every equilibrium point is analyzed. The global dynamics of the model are investigated numerically and confronted with the obt

A real method of predication brake pad wear ,could lead to substantiol economies of time and money. This paper describes how such a procedure has been used and gives the results to establish is reliability by comparing the predicted wear with that which actually occurs in an existing service. The experimental work was carried out on three different commercial samples ,tested under different operation conditions (speed,load,time...etc)using a test ring especially modified for this purpose. Abrasive wear is mainly studied , since it is the type of wear that takes place in such arrangements. Samples wear tested in presences of sand or mud between the mating surfaces under different operational conditions of speed, load and braking time .Mec