Explore the vast range of titles available.

The construction of a precast flat plate frame of buildings is considered for its implementation during the restoration of the housing stock of Ukraine. The analysis of the precast flat plate floor system of the frame structural system by using the yield line method showed that in the ultimate state the floor is divided into separate discs along the joints of precast plates. This makes it possible to determine the load-bearing capacity of the floor by considering each plate taking into account their supporting and loading conditions. Based on this, experimental tests of three full-size over-columned plates of a precast flat plate floor system are carried out, according to the diagram closest to the actual scheme of their operation as part of the floor. The general deflections of the plates, moments of crack formation and width of their opening, as well as strains of concrete and reinforcement in characteristic cross-sections of the plates are determined. Based on the experimental tests, the accepted failure scheme of the over-columned plates of the precast flat plate floor system is confirmed and the feasibility of applying the yield line method to the calculation of their bearing capacity is proven.

Reinforced Concrete (RC) barriers are used for different purposes in the highway inventory. An important purpose is the use of concrete barriers to act as railing that protects bridge piers against vehicular collision force (VCF). Therefore, these barriers are designed to absorb the collision energy and/or redirect the vehicle away from the parts being protected. Accurate estimation of the capacity of RC barriers during crash events is an important consideration in their design and placement. The American Association of State Highway and Transportation Officials (AASHTO) considers yield line analysis (YLA) with the V-shape failure pattern to predict the barrier capacity. AASHTO’s analysis method involves some assumptions that are intended to simplify the analysis process. Some of these assumptions have been shown to underestimate the actual barrier capacity and might disqualify many existing RC barriers from acting as intervening structures due to structural inadequacy. Many researchers have proposed alternative failure patterns and methodologies in an attempt to better predict the capacity of RC barriers. This research shows that AASHTO’s YLA, with the current V-shape failure pattern, can be improved and still predict the barrier capacity when some of the simplifying assumptions are eliminated. Also, the research presents an alternative innovative truss analogy model to predict the capacity of RC barriers. The results of the improved YLA and the proposed truss model are validated by finite element analysis (FEA) using Abaqus. The results of this research will help structural engineers in the highway industry to initially design new barriers for the intended capacity as well as estimate the capacity of existing ones.

Reinforced concrete (RC) flat slabs are a widely adopted structural system in buildings due to their efficient load transfer mechanism and architectural flexibility. Unlike conventional beam-supported slabs, flat slabs are directly supported by columns, reducing overall building height and simplifying construction. However, their design requires complex static analysis to ensure structural safety and performance under various loading conditions. Since RC flat slabs offer significant advantages in terms of cost-effectiveness and spatial efficiency, they present unique design challenges, particularly concerning deflection control and punching shear resistance. Addressing these issues requires precise static analysis methods, such as the equivalent frame method, finite element modelling, and yield line analysis. Several widely recognized design standards including Eurocode 2, the American Concrete Institute (ACI) standards, and the Indian Standard (IS) codes are elaborated in this research. These codes provide different methodologies for analyzing bending moments, shear forces, and deflection control, offering a comparative perspective on their design recommendations. The insights from this research contribute to improved design practices for engineers and architects, ensuring safer and more efficient RC flat slab structures. By providing a comprehensive understanding of static analysis and key design considerations across multiple design codes, this study aids in the development of more reliable and durable structural solutions in modern construction.

Yield line analysis is a powerful method used in structural engineering to evaluate the ultimate load-carrying capacity and failure mechanisms of reinforced concrete slabs. in this study finite element method is used to analyze three side supported(fixed) slab with concentrated loading on different location to find yield line pattern of slab. The finite element software Ansys is used to analysis the slab. this study performed on total five model or specimens. concentrated loading is positioned as-in centre of slab, shifted along central-line along the length, shifted along central-line transverse to the length. ANSYS R2 is used to simulate and analyse the structural behaviour of different models. The analysis aimed to define the yield line pattern and compare the behavior of slab for different loading condition. Overall the objective of study structural behaviour and to find the yield line pattern of slab subjected to concentrated loading at different locations.

This work's objective is to analyze and dimension of Reinforced Concrete stringers using the Engesser-Courbon Method for moving loads and the Yield Line Theory, Areas of Influence and Grid Method for determining permanent loads. It also to evaluate the influence of the number and stiffness of crossbeams on load distribution. With the research, concluded that the Areas of Influence method has shown to be more effective on decks with high crossbeams stiffness. The Yield Line Theory offered more accurate results compared to the Areas of Influence Method. The number of crossbeams was what most impacted the difference in steel areas between the decks. When the crossbeams numbers went from 4 to 5 and from 5 to 6, there was a reduction in the steel areas of the reinforcements by 25%, 35% and 40% on average, between the steel areas of the vertical stirrups positive and negative longitudinal reinforcements respectively.

Skew slabs have various applications, e.g. as floor of bridges and buildings. This is pertinent when it is not possible to cross a river or gap at an angle of 90°. Design aids and plans suggested by various codes are applicable for standard skew angles, i.e. 15°, 30°, 45°, etc. with selective spans only. However, in actual practices, several cases are encountered, wherein skew angle and aspect ratio of the slab panel do not fit the recommended guidelines. This occurs due to the very high land cost and space limitations. The present study proposes an analytical model for the design of skew slabs with any skew angle and aspect ratio. The developed model indicates that skew slabs simply supported along two opposite parallel sides and free along the other two sides are suitable for the construction of bridges having short diagonal larger than the span. The developed model validates the assumptions considered in terms of collapse loads and crack patterns experimentally and numerically. This shall facilitate engineers during the design of skew slab bridge for any skew angle and aspect ratio, without deviating from the alignment of the road.

Recent experimental tests on rectangular reinforced concrete (RC) beam-slab systems, subject to gravity loading, reveal that the mode of failure is generally a combined \"beam-slab failure\" (and rarely, a \"slab-alone failure\"). Theoretical studies have also established that the collapse load can be predicted accurately by yield line analysis, accounting for the formation of plastic hinges in the beams along with yield lines in the slab. However, techniques to predict the complete load-deflection plots of such tested beamslab specimens have not yet been reported in the literature. This paper attempts to fil this gap by showing how a displacementcontrolled numerical analysis using finite element analysis software such as Abaqus can capture the complete behavior, including the mode of failure. The concrete is modeled as a three-dimensional (3-D) solid element and the reinforcement is modeled as a onedimensional (1-D) truss element, assuming perfect bond. It is seen that the numerically generated load-deflection plots are in good agreement with the experimental data. With the help of such numerical simulations, it is possible to carry out further studies on beamslab systems with various configurations and possible combinations of beam/slab sizes and reinforcements, without needing to carry out laborious and expensive experiments in the laboratory. Keywords: beam-slab systems; damaged plasticity model; failure mode; load-deflection behavior; nonlinear analysis.

This article investigates the punching shear behavior of recycled aggregate concrete (RAC) two-way slabs. Ten 1500 mm × 1500 mm × 100 mm slabs were tested monotonically. Eight slabs were cast with RAC, whereas two control slabs were cast with natural aggregate concrete (NAC). The RAC incorporated coarse recycled concrete aggregate (RCA) at replacement levels of 25%, 50%, 75% and 100%. Two flexural reinforcement ratios (0.8% and 1.5%) were examined. The results show that the normalized punching shear strength of 100% RAC slabs decreased by 6.5% and 9% compared to NAC slabs for ρ = 1.5% and ρ = 0.8%, respectively. Doubling the amount of flexural reinforcement can increase the punching shear capacity of 100% RAC slabs by up to 45%. A punching shear database of 44 RAC slabs from literature and the 8 RAC slabs presented in this study revealed that the punching shear strength of RAC slabs predicted by ACI 318 was conservative, except for slabs with low reinforcement ratios (<0.6%). The punching shear strength predicted by Eurocode 2 gave more conservative results for all levels of RCA replacement and all flexural reinforcement ratios. A yield-line analysis also showed that the failure mode of the RAC slabs was controlled by punching shear.

In the conventional method of strength design of reinforced concrete (RC) beam-slab systems, it is assumed that if the beams are adequately stif, the slab and beams can be analyzed and designed separately under factored gravity loads. This paper demonstrates, through yield line analysis and load testing of isolated beam-slab systems, that such a design, which tacitly assumes a 'slab alone failure' mechanism, is irrational and overconservative (failing at a load level much higher than expected). The actual collapse of the conventionally designed beam-slab system invariably involves a combined beam-slab failure mechanism. It is therefore more rational and economical to design explicitly for such a collapse mechanism, accounting for plastic hinge formation in the beams along with yield lines in the slab. The proposed method suggests provision of minimum slab steel (as prescribed by the design code), and then designing the beams aiming for a combined two-way beam-slab failure. Experimental load testing establishes that the collapse occurs as planned and that the proposed economical design has the desired code-specified safety margins. Keywords: beam-slab system; combined beam-slab failure; rational design methodology; slab alone failure; yield line analysis.

The incorporation of agricultural waste into construction materials represents a promising pathway toward achieving carbon neutrality in the building sector. This study investigates the flexural performance of a novel prefabricated external wall panel composed of corn straw concrete (CSC), an eco-friendly composite material that utilizes waste corn straws. While prior studies have explored rice straw and hemp fiber concrete, they primarily focused on the mechanical properties of these materials rather than the design of prefabricated panels. This study fills the gap by optimizing reinforcement ratio and window opening layout for CSC panels, and validating their structural viability for prefabricated enclosures. An optimal mix proportion was identified, which meets the mechanical requirements for non-load-bearing applications. Four prototype panel specimens were subjected to out-of-plane monotonic loading, considering variables including reinforcement ratio (0.18% vs. 0.24%) and the presence of a window opening (25% area ratio). Results indicated that increasing the reinforcement ratio significantly enhanced the ultimate load capacity by up to 33.3% (from 45 kN to 60 kN)—an enhancement effect that was 12–15% higher than that of reported rice straw concrete. In contrast, the introduction of an opening reduced the ultimate load capacity by 11.1–16.7%. A detailed nonlinear finite element model (FEM) was developed and validated against experimental results. The validation results indicated deflection error of 7.7–12.8% (mean: 9.33%; SD: 2.05), ultimate load error of 7.7–11.1% (mean: 9.48%; SD: 1.32), and a correlation coefficient (R2) of 0.96 between simulated and experimental values. Furthermore, analytical methods for predicting the cracking moment (with an average error of 5.97%) and ultimate flexural capacity, based on yield line theory (with an average error of 8.43%), were proposed and verified. This study demonstrates the structural viability of CSC panels and provides a sustainable solution for waste reduction in prefabricated building enclosures, contributing to greener construction practices.