Experimental Investigation and Design of Hollow Section, Centrifugal Concrete-Filled GFRP Tube Columns

The compressive response of hollow section, centrifugal concrete-filled GFRP tube (HS-CFGT) members is examined experimentally and reported analytically in this paper. A total of 17 specimens separated into two groups were tested; the specimens in each group were of four different lengths and included thirteen straight columns and four tapered columns. The details of the test rigs, procedures as well as key test observations composed of ultimate-moment capacities, load-displacement curves, and failure modes were truthfully reported. The test results were analyzed to evaluate the influence of initial eccentricity on the structural performance. Therefore, the aim of this paper is: (1) to propose a proper coefficient, φe, reflecting the effect of initial eccentricity based on the Chinese design code; and (2) to determine a new confinement coefficient, kcc = 1.10, for centrifugal concrete confined by GFRP tubes. Comparisons of the present design codes and specifications of confined concrete members with test results on 17 full-scale tube columns are also presented. Accordingly, new design equations, whose predictions generally agree well with the test results, are recommended to estimate the compressive capacity of the proposed HS-CFGT columns.

Analysis of Rectangular Reinforced Concrete Liquied Tanks by Using Yield Line Theory

In the analysis of rectangular reinforced liquid storage tanks, a method assuming linear-elastic behavior for material can be used, i.e., the strip method, the moment coefficient method, the finite element method, etc. In the analysis of these types of tanks, tank walls can be considered as slabs. In this study, tank walls were analyzed as slabs subjected to hydrostatic loading; in the analysis, the yield line theory is used because it is more suitable for the linear inelastic behavior of reinforced concrete slabs than the ones based on the linear elastic theory. An iterative algorithm based on yield line theory is presented for the design of isotropically reinforced recrangular concrete slabs supported along all four edges. A computer program is coded which predicts the location of yield lines for the slabs depending upon certain parameters. As a result of this prediction, the manual design of such slabs can be significantly simplified by the use of the coefficient obtained by using the program. It was shown that the analytical computation of the ultimate moment per unit length requires the solution of a highly nonlinear system of equations. This difficulty was overcome by utilizing an iterative technique within the computer program. It also gives the value of the ultimate moment per unit length of the yield line.

Flexural Behaviour of Chicken Mesh Ferrocement Laminates with Partial Replacement of Fine Aggregate by Steel Slag

Bending tests were conducted on ferrocement laminates containing chicken mesh and steel slag. The fundamental goal of the examination was to investigate the effects of partial substitution of fine aggregate by steel slag in cement mortar combining chicken mesh of different volume fractions as reinforcement in thin ferrocement laminates. The following variables were investigated: (a) volume fraction of chicken mesh as 0.94%, 1.88%, 2.82%, and 3.77% and (b) level of steel slag substitution from 0% to 50% by weight fine aggregate. Results show that ferrocement laminates with chicken mesh of volume fractions of 3.77% and 30% substitution of fine aggregate with steel slag display better performance in terms of load deflection behaviour, first crack load, ultimate load, energy absorption, and ductility ratio when related with other specimens. An analytical model has been proposed to predict the ultimate moment carrying capacity of ferrocement laminates under flexure to validate the experimental results.

Textile-Reinforced Mortar (TRM) Strengthened One-Way Reinforced Concrete Slabs

The issue of upgrading and strengthening the reinforced concrete (RC) infrastructure has become of great importance. Recently, textile-reinforced mortar (TRM) was used in the field of structural strengthening. In the current study, using of TRM for flexural retrofitting of one-way reinforced concrete (RC) slabs was experimentally and theoretically investigated. The parameters examined included; the number of TRM layers (1, 3, 5 layers) and the strengthening configuration fully and partially). For this purpose, eight specimens were prepared and tested under three points- loading up to failure. The result showed that the TRM increases substantially the flexural capacity of RC slabs. The highest flexural capacity increase recorded was 103 %. It was also noted that increasing the number of retrofitting layers resulted in different increases in the flexural capacity. It was also shown that the strengthening configuration plays an important role in the effectiveness of the technique. The fully covered approach showed higher loading capacity than the partial cover technique provided that the same TRM layer is applied. Finally, the ultimate moment of the strengthened specimens was calculated theoretically and compared with that obtained experimentally. The results of calculations showed a good agreement between the theoretical and experimental results.

Seismic Analysis of Multi Storey Building Using Strong Column Weak Beam Ratio (SCWB) in Different Zones of India

An earthquake structures are mandatory to avoid significant damages (i.e., collapse) and aims that structure withstand a major earthquake without collapse. The design approach adopted is to ensure that the columns of the structure more capable to resist moments than beam; to avoid progressive collapse of structure due to failure of columns in lower level; it is necessary the columns have stronger than beams (strong column weak beam). The concept of SCWB is to ensure that plastic hinge formed in the beam not in the column; this help in dissipating the more energy along with providing ductility to the structure. If the plastic hinge is formed on the both ends of column then, the column is not able to spread the plasticity and collapse which are leads to global failure. The failure modes in all past earthquake is exactly opposite i.e, strong beam weak column; and comes to sway mechanism and fails to collapse. For this it is foreseen that the values of ratio of Mc/Mb (ratio of sum of ultimate moment of resistance of columns to sum of ultimate moment of resistance of beam) in the beam-column joint are stated by many design codes and the values are different ranging from 1.2,1.3,1.4,1.5 to 2, etc. Another effect of ratio Ic/Ib (ratio of moment of inertia of column to moment of inertia of beam) have been studied but the exact meeting of SCWB behaviour in the structures at the time of collapse not stated clearly. The Mc/Mb and Ic/Ib ratio are very important to prevent damage in the structure under seismic action. In the present work, attempts are made to achieve exact ratio of exact strong column weak beam. In this study, the combined effect of two ratio (Mc/Mb, Ic/Ib) simultaneously investigated in different zones of India to find out exact SCWB ratio’s value for to meet the SCWB behaviour. Different numerical examples are presented of combine ratios (Mc/Mb,Ic/Ib) and pushover analysis is performed on each ratio’s. The result of the investigation highlighted on the objective that is to find exact SCWB ratio value considering the parameter like target displacement, ductility ratio, hinge response etc.

The Ambivalent Conjunction of Modernity and Human Rights

Modernity is a stage in societies’ development that is the corollary of enlightenment. It has variously been conceived to be the ultimate moment in the unfolding of human history in the sense that norms and values, and practices and institutions are nearly or at their most perfect. However, the conceived prelude to or realization of utopia does not accord with reality in many specific modern societies, even those that are generally considered to be the forerunners of modernity. In Africa, the onset of modernity and its extension into the diverse realms of human beings’ lives has entailed norms and values, and practices and institutions that are the genesis of dystopia. This article examines the ambivalent nexus of modernity and human rights in Africa from the onset of the modernization project to date. Using critical theory, the article argues that although modernity is credited with the birth of human rights, in Africa its primary actors, namely capital, the markets, and the state, are either ambivalent to and/or causal to widespread and deep human rights violations. The human rights violations are systemically and systematically cast as incidental and spurious rather than the hallmarks of modernity. Judicial, political, and educational institutions act and reiterate their capacities to address the incidental/spurious human rights violations, despite abundant evidence that, as part of modernity, these institutions are ambivalent to human rights and, therefore, can only mask the reality and perpetuate human rights violations. This general stance is the consequence of the pervasive logic of capital. This article explains how this pervasive phenomenon in its various forms, such as state capitalism and global capitalism, coupled with neopatrimonialism, has impacted the institution and practice of human rights in Africa. The analysis concludes that though modernity is credited with the birth of human rights regimes, its historicity has been causal of significant violations of human rights. The violations unleashed by capital are exacerbated by political elites who, in their processes of policy-making and budgetary deliberation, and implementation, marginally conceive nation-extensive notions of common good. Consequently, violation of human rights is rampant.

Analisis dan Desain Struktur Atas Hotel 10 Lantai di Kabupaten Bogor terhadap Beban Gempa

The type of soil at the location of the hotel building is a type of medium land (D). The applications used in this study are ETABS V16.1 and AutoCAD. Based on the PUSKIM website, the Ss and S1 Bogor City were 0.881 and 0.356, respectively. Based on the results of the analysis of the application ETABS V16.1 obtained fewer reinforcement design results than the existing reinforcement. The maximum nominal moment of the beam is 508.3 kNm while the ultimate moment is 498.4 kNm. The maximum nominal shear force of the beam is 565.9 kN while the ultimate shear force is 538.4 kN. The maximum nominal moment of the column is 1488.5 kNm while the maximum ultimate moment is 1478 kNm. The maximum nominal axial force of the column is 6291 kN while the maximum ultimate axial force is 6287 kN. The maximum nominal bending moment of the floor plate is 41.3 kNm while the maximum ultimate moment is 39.9 kNm. The maximum nominal shear force of the floor plate is 234.7 kN while the maximum ultimate shear force is 228.9 kN. The nominal shear force of shear wall is 8238.5 kN while the ultimate shear force is 8194.7 kN. Based on the internal forces, the building that has been built is in accordance with the plan so that it is safe to withstand earthquake loads.

Experimental Study on the Flexural Behavior of Concrete-Filled Steel Box Slabs

Different to conventional reinforced concrete or steel material, a new type of concrete-filled steel box slab has been proposed by effectively integrating the combined benefits of both steel and concrete. By filling concrete, this type of slab could avoid the local bucking of steel plate and then could provide a high moment capacity. Therefore, this study aims to investigate the flexural behavior of concrete-filled steel box slabs through testing seven specimens and characterize their failure characteristics, stress distribution and ultimate moment capacity. A comprehensive parametric study focuses on the influence of the steel plate thickness, the stud and stiffening plate on the slab flexural behavior. The results show that concrete-filled steel box slabs had a high moment capacity and good ductility. The thickness of the steel plate had a significant influence on the moment capacity of the specimen. The stud led to the reduction of the moment capacity of the slab. The stiffening plate effectively improved the flexural behavior of the specimen. Moreover, a calculation method was formulated to describe the moment capacity of the slab and compared with experimental results. The results show that the proposed method for the moment capacity of the slab was conservative and reasonable.

Moment carrying capacity of RSCC beams incorporating alccofine and fly ash

This paper analyses the structural behavior of reinforced self-compacting concrete beams under two-point loading. A total number of five beams were cast with varying quantities of alccofine (i.e., 0, 5, 10, and 15%) and constant dosage of fly ash (i.e., 25%) and tested for examining the load-deflection curves and ultimate moment carrying capacity of reinforced self-compacting concrete beams. From obtained experimental results, it was found that the load-carrying capacity was increased when the beam with the addition of alccofine and fly ash is compared with the normal concrete beam. The experimental obtained ultimate strength values were compared with theoretically predicted values using IS 456-2000, ACI 318-11, and CSA A23.3-04 codes.

Comparison of the design of prestressed concrete hollow-core floor units with Eurocode 2 and ACI 318

A typical 1200 mm (48 in.) wide × 200 mm (8 in.) deep prestressed concrete hollow-core unit is analyzed and designed in order to make a comparison between Eurocode 2 and ACI 318-08. This includes calculations for serviceability limit state of stress and moment of resistance, ultimate moment of resistance, ultimate shear capacities, flexural stiffness (that is, for deflection), and cover to pretensioning tendons for conditions of environmental exposure and fire resistance. Concrete cylinder strength is 40 MPa (5.8 ksi), and concrete cube strength is 50 MPa (7.3 ksi). The hollow-core unit is pretensioned using seven-wire helical strands. Worked examples are presented in parallel formation according to Eurocode 2 and ACI 318. For uniformly distributed loads, the design criterion between the service moment to service moment of resistance (Ms/Msr for EC2 and Ms/Msn for ACI 318) and the ultimate design bending moment to ultimate moment of resistance (MEd/MRd for EC2 and Mu/φMn for ACI 318) is well balanced for this example. Usually the service moment is critical unless the amount of prestress is small. For EC2-1-1, flexurally uncracked shear capacity VRd,c is only limiting when the span-to-depth ratio in this example is less than about 35. For ACI 318, flexurally cracked shear capacity φVci is limiting when span-to-depth ratio is 42, showing that shear cracked in flexure will often be the governing criterion.