Numerical analysis of I-Lam honeycomb sandwich panels for collision protection of reinforced concrete beams

Bridge damage due to over-height vehicle collisions is a major issue throughout the transportation network with damages ranging from minor distortion or spalling in fascia girders to almost complete bridge destruction. Repairing such damages resulted from over-height vehicle collisions is expensive, and it includes costs for bridge repair, and rerouting traffic as well as indirect economic and societal costs. In this study, in correlation with a series of impact tests for reinforced concrete beams with or without Impact-Laminate (I-Lam) panel protection by a wooden projectile, the numerical modeling using the finite element codes ABAQUS is conducted to simulate the over-height vehicle impact, and a good agreement with the available experimental data is obtained. Parametric studies are conducted to further investigate the effects of design parameters (e.g. the velocity of projectile, I-Lam parameters, and core layer sequence, etc.) on the effectiveness of the protection system. The observed phenomena from the parametric studies reflect a design philosophy aiming at improving protection efficiency and providing important information on design of I-Lam honeycomb sandwich collision protection systems for field application.

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Performance of Reinforced Concrete Beams with Multiple Openings

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.857.162 ◽

2020 ◽

Vol 857 ◽

pp. 162-168

Author(s):

Haidar Abdul Wahid Khalaf ◽

Amer Farouk Izzet

Keyword(s):

Reinforced Concrete ◽

Ultimate Load ◽

Concrete Beams ◽

Load Capacity ◽

Reinforced Concrete Beams ◽

Design Parameters ◽

Ultimate Load Capacity ◽

Concentrated Load ◽

Simply Supported ◽

Group I

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.

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Strengthening of Reinforced Concrete Members using Post-Tension Cables: A Parametric Research

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b1250.0782s319 ◽

2019 ◽

Vol 8 (2S3) ◽

pp. 1334-1338

Keyword(s):

Reinforced Concrete ◽

Parametric Study ◽

Concrete Beams ◽

Load Capacity ◽

Reinforced Concrete Beams ◽

Design Parameters ◽

Internal Stresses ◽

Force Magnitude ◽

Post Tensioning ◽

Post Tension

In building construction, post-tensioning allows longer clear spans, thinner slabs than the reinforced concrete beams. This paper presents a theoretical investigation on the behavior of existing reinforced concrete beams strengthened with post-tensioning cable(s) for increasing their load capacity. The proposed post-tensioning technique consists of stressing cable passing through a structural beam element starting from the top/bottom side and traversing the beam to the bottom/top side and then return back to the original side. A theoretical parametric study is conducted to study the effect of post-tensioning parameters on the internal stresses to optimize the design parameters. An excel spread sheet program was developed to calculate the internal straining actions at critical sections of the beam. A parametric study including the cable length, inclination angle of the cable and pre-stressing force magnitude was performed by using this program. This parametric study, led to well-defined guidelines for the proper use of the strengthening of beams by pre-stressing cables with adequate geometrical conditions of the cables

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Flower pollination-based optimal design of reinforced concrete beams with externally bonded of FRPS

Advanced Composites Letters ◽

10.1177/2633366x20962499 ◽

2020 ◽

Vol 29 ◽

pp. 2633366X2096249

Author(s):

N Sundar ◽

PN Raghunath ◽

G Dhinakaran

Keyword(s):

Reinforced Concrete ◽

Optimal Design ◽

Concrete Beams ◽

Weight Ratio ◽

Design Procedure ◽

Reinforced Concrete Beams ◽

Design Parameters ◽

Flower Pollination ◽

Reinforced Polymer ◽

Externally Bonded

The optimal design of reinforced concrete beams (RCBs) and structures with an objective of improving the chosen performances is an important problem in the field of construction works. Recently, the concrete beams, structures, and walls are strengthened externally by bonding fiber-reinforced polymer strips (FRPS). Usually, FRPS are employed in rehabilitation of existing beams, bridges, and other structural elements. This article modifies the problem of designing new RCBs with appropriate selection of FRPS with a goal of exploiting the benefits of FRPS such as higher tensile strength, better corrosion resistance, higher stiffness-to-weight ratio, and longer life. It, firstly, proposes an artificial neural network-based mathematical model for assessing the performances of RCBs bonded with FRPS from the data obtained from 69 FRPS-glued RCBs and then develops an optimal design procedure employing flower pollination-based optimization, which is imitated from the pollination process of plants, for obtaining design parameters of FRPS-glued RCBs with a view of enhancing both the ultimate load and the deflection ductility. It presents optimal design parameters of five FRPS-glued RCBs and experimentally validates the performances.

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