Abstract. Reinforced concrete (RC) deep beams mainly fail in shear, brittle and sudden in nature can lead to calamitous consequences. Thence, it is critical to determine the shear characteristics of RC deep beams accurately due to involving many parameters at same time. Some of the recent researches have shown that current equations for predicting ultimate shear strength are non-conservative when applied to high strength concrete (HSC) beams as well as some of design codes provisions. There are different approaches for analyzing the behavior of beams in shear.In this paper, a semi-empirical approach is adopted in which a database of existing experimental and literature results of deep beams, d > 300 mm & d < 300 mm, failing in shear under two point loads statically at mid-span, was constructed. The database, 725 deep beams, was used to propose two simplified shear equations using multiple regression analysis, IBM-SPSS-Statistics, to find out and evaluate the most important factors affecting the ultimate shear strength formulating them in a suitable predictive equation for the ultimate shear strength of deep beams without web reinforcement (stirrups). The test database covers a wide range of individual parameters as: cylindrical concrete compressive strength (20 f′ c 104 MPa), longitudinal main steel reinforcement ratio (0.17% q s % 6.64%), effective depth of deep beams "d" (127-1000 mm), shear span to effective depth ratio (1 a/d 2.5), Beam width "b"; b/d < 1, where all database from literature were based on two point loading.This paper concluded that, the proposed equations seem to predict the ultimate shear strengths well, conservative and give lower coefficient of variation "COV" and smaller range of results when compared with the available methods of design; ECP203-2007, ACI 318-14, CSA, and BS8110 codes and other equations proposed by Sudheer Reddy, Zararis, Bazant, Zsutty and Shah.
The recent development of smartphones and the introduction of newer mobile phone networks led to increasing concerns over the prolonged exposure of delicate human organs to mobile phone radiation. This study investigates the Specific Absorption Rate (SAR) and temperature distributions inside anatomical head model exposed to mobile phone radiation. The effects of different microwave frequencies (0.9, 1.8, and 3 GHz) and different antenna positions (voice and video calling positions) were studied. The propagation, penetration, and absorption equations of the microwave radiation as well as the bioheat equation were numerically solved inside the computational domain. The numerical results of the present study were verified by comparison to other published numerical solutions. The Peak overall SAR and temperature rise were found in the voice calling position for the 3 GHz frequency as 14.9 W/kg and 1.6 °C, respectively. The model showed negligible peak SAR and temperature rise values for the video calling position. Moreover, the peak SAR and temperature rise locations are not correlated. Additionally, the temperature rise exceeded 63% of the final value at 6 minutes of exposure time for all the studied microwave frequencies.
Currently, there is no general agreement on a theory describing the response of reinforced concrete members without web reinforcement. Many structural systems are usually performed using empirical or semi-empirical expressions provided by codes of practice that do not consider the influence of many governing parameters. In this paper, a comparison between values of current experimental shear strength and those of various international design approaches like ACI, Canadian, FIB and the method proposed by Sudheer, Zararis ,Zsutty ,Shah ,Bazant and Russo. Eighteen simple span high strength reinforced concrete "HSRC" deep beams without web reinforcement were tested and analyzed under two static point loads at mid-span of the beam to examine the contribution of various parameters on the shear capacity of HSRC beams. The main studied parameters are f'cu=50 MPa, three values of tension reinforcement-ρ%-(0.73%,1.21% &1.83%) and shear span to effective depth ratio-a/d-(2,1.5 &1). As a conclusion of this paper, ACI and FIB code provisions for shear in HSC are safe for use with the exception that CSA should be used with care. Despite numerous studies, there is still a need to develop a clear understanding of the shear behavior of HSC beams without web reinforcement. Therefore, this experimental program was arranged to evaluate the shear behavior and to increase the shear database on HSRC deep beams.
Currently, there is no general agreement on a theory describing the response of reinforced concrete members without web reinforcement. Many structural systems rely on design is usually performed using empirical or semi-empirical expressions provided by codes of practice that do not consider the influence of many governing parameters. In this paper, a comparison between values of current experimental shear strength and those of various international design approaches have been calculated and analyzed on 18 simple span HSRC deep beams without web reinforcement were tested under monotonic two point loads at the mid span to examine the contribution of various parameters on the shear capacity of HSRC beams like; f International Conference on Civil and Architecture Engineering ICCAE-11-2016 cu I. Introduction =60 MPa, three values of tension reinforcement (0.73%,1.21% &1.83%) and shear span to effective depth ratio (2,1.5 &1) were selected to mainly study the behavior of deep beams, where typical shear failure can be anticipated.
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