scholarly journals Experimental Investigation on the Structural Performance of Single Span Hollow Core Slab under Successive Impact Loading

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 599
Author(s):  
Kamal Amin Chebo ◽  
Yehya Temsah ◽  
Zaher Abou Saleh ◽  
Mohamad Darwich ◽  
Ziad Hamdan
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Behavior ◽  
Impact Loading ◽  
Structural Response ◽  
Experimental Program ◽  
Hollow Core ◽  
Review Section ◽  
Reinforced Concrete Slabs ◽  
Hollow Core Slab ◽  
Post Tensioned

In Lebanon and many other countries where structures are vulnerable to impact loads caused by accidental rock falls due to landslides, specifically bridges with hollow core slab, it is mandatory to develop safe and efficient design procedures to design such types of structures to withstand extreme cases of loading. The structural response of concrete members subjected to low velocity high falling weight raised the interest of researchers in the previous years. The effect of impact due to landslide falling rocks on reinforced concrete (RC) slabs has been investigated by many researchers, while very few studied the effect of impact loading on pre-stressed structures, noting that a recent study was conducted at Beirut Arab University which compared the dynamic behavior of reinforced concrete and post-tensioned slabs under impact loading from a 605 kg impactor freely dropped from a height of 20 m. Hollow core slabs are widely used in bridges and precast structures. Thus, studying their behavior due to such hazards becomes inevitable. This study focuses on these types of slabs. For a better understanding of the behavior, a full scale experimental program consists of testing a single span hollow core slab. The specimen has 6000 mm × 1200 mm × 200 mm dimensions with a 100 mm cast in a place topping slab. Successive free fall drops cases from 14 m height will be investigated on the prescribed slab having a span of 6000 m. This series of impacts will be held by hitting the single span hollow core slab at three different locations: center, edge, and near the support. The data from the testing program were used to assess the structural response in terms of experimental observations, maximum impact and inertia forces, structural damage/failure: type and pattern, acceleration response, and structural design recommendations. This research showed that the hollow core slab has a different dynamic behavior compared to the post tensioned and reinforced concrete slabs mentioned in the literature review section.

Numerical Simulation of Impact Response Behavior of Rectangular Reinforced Concrete Slabs under Falling-Weight Impact Loading

2011 ◽  
Vol 82 ◽  
pp. 266-271 ◽  
Author(s):  
Norimitsu Kishi ◽  
Yusuke Kurihashi ◽  
Sara Ghadimi Khasraghy ◽  
Hiroshi Mikami
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Impact Loading ◽  
Dynamic Responses ◽  
Concrete Slabs ◽  
Analysis Method ◽  
Numerical Analysis Method ◽  
Reinforced Concrete Slabs ◽  
Weight Impact ◽  
Falling Weight

A numerical analysis method for rectangular reinforced concrete slabs under falling-weight impact loading is established. The proposed method using finite element analysis incor-porates a simple constitutive model for concrete elements. The applicability was investigatedcomparing the numerical results with the experimental data. Falling-weight impact tests wereconducted on reinforced concrete slabs with different supporting conditions. These were: a slabwith line supports on four sides; a slab with two line supports on two opposite sides (the othertwo sides were free); and a slab with one line and two corner-point supports. Following resultswere obtained from this study: (1) the time histories of dynamic responses are well predictedby using proposed numerical analysis method; (2) maximum reaction forces and the maximumdeflections in the slab center below the loading point, and characteristics of the damped freevibration after falling weight was rebounded, can be better predicted; and (3) major crackpatterns can be roughly predicted despite of support conditions.

THE EFFECT OF IMPACT LOADS ON PRESTRESSED CONCRETE SLABS

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Youmn Al Rawi ◽  
Yehya Temsah ◽  
Hassan Ghanem ◽  
Ali Jahami ◽  
Mohamad Elani
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Shear Mode ◽  
Reinforced Concrete Slab ◽  
Finite Element Program ◽  
Reinforced Concrete Slabs ◽  
The Impact

Many research studies have been conducted on the effect of impact loading on structures, and design procedures were proposed for reinforced concrete (RC) slabs; however the availability of these studies and procedures are limited for prestressed slabs. The proposed research will examine, using numerical analysis, the impact of rock fall on prestressed concrete slabs with equivalent moment capacity reinforced concrete slabs. It is expected that prestressed concrete slabs will have different behavior to resist impact loading compared with traditional reinforced concrete slabs. The thickness of the prestressed concrete slab will be 25cm whereas that of the reinforced concrete slab will be 30cm. The impact loading consists of 500Kg drop weight. The drop height will be 10m, 15m and 20m.The structural analysis is performed using a Finite Element program "ABAQUS". A comparison will be done between both slab types in terms of failure mode, damage, and deflection. It has been found that both slabs failed in punching. However, the RC slab performed better than the prestressed concrete slab with respect to the value of the deflection at mid-span, while both showed punching shear mode of failure.

BEHAVIOR OF REINFORCED CONCRETE SLABS UNDER ACCIDENTAL IMPACTS

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Shamsoon Fareed
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
High Mass ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Numerical Predictions ◽  
Operational Life ◽  
The Impact

Loads resulting from activities such as rock fall, heavy drop weights (for e.g. equipment's, heavy machines during installation), missile and aircraft interaction with slabs may results in loading intensity which have higher magnitude as compared to static loading. Based on the velocity of the impacting object at the time of contact, these activities may result in impact loading. Therefore, slabs designed should provide resistance to these accidental loading during their entire operational life. In this study, a dynamic non-linear finite element analyses were conducted to investigate the behavior of the reinforced concrete slabs subjected to high-mass low-velocity impacts. For this purpose, initially an already published impact test results were used to validate the numerical predictions. Following validation, a study was conducted to investigate the influence of the impact velocity on the behavior of the reinforced concrete slab. Based on the numerical investigation, it was found that the velocity of the impacting object has a significant influence on the behavior exhibited by slab under impact loading. Furthermore, it was also found that the behavior of slab under impact is both local and global. Local behavior is associated with the damage caused at the contact area of the slab and the impactor, whereas global behavior refers to the overall deformation of the slab when stress waves move away from the impact zone and travel towards the supports.

Modelling the Response of Simply-Supported Two-Way Reinforced Concrete Slabs Exposed to Fire

2016 ◽  
Vol 711 ◽  
pp. 588-595
Author(s):  
Emran Baharudin ◽  
Luke Bisby ◽  
Tim Stratford
Keyword(s):  
Reinforced Concrete ◽  
Computational Study ◽  
Concrete Structures ◽  
Structural Response ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Fire Engineering ◽  
Reinforced Concrete Slabs ◽  
Structural Fire Engineering ◽  
Fire Codes

The historically good performance of concrete structures in real fires, and the lack of urgent drivers for the concrete industry to support research on the fire performance of concrete structures, means that research on the full frame response of concrete buildings to fires has received much less attention than for steel-framed structures. However, a credible understanding of, and ability to model, the response of concrete structures under fire exposure is crucial to make further progress in the field of structural fire engineering, and to make best use of the flexibility enabled by performance-based fire codes. This paper presents a computational study on the structural behaviour of reinforced concrete slabs during fire tests undertaken by Zhang et al.[16]. The distribution of stresses in the slabs is discussed, as is the need for further research to better understand structural response during fire. Amongst other factors, the assumed tensile strength of the concrete is crucial to accurately predict response. The results corroborate the existing consensus that concrete slabs in real buildings can, in some cases, withstand fires for longer than expected; this is due to mobilisation of membrane actions, amongst other factors.

scholarly journals Analysis of Fiber-Reinforced Concrete Slabs under Centric and Eccentric Load

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7152
Author(s):  
Zuzana Marcalikova ◽  
Vlastimil Bilek ◽  
Oldrich Sucharda ◽  
Radim Cajka
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Concrete Slabs ◽  
Detailed Knowledge ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
3D Deformation

Research on the interaction between slabs and subsoil involves the field of materials engineering, concrete structures, and geotechnics. In the vast majority of cases, research focuses on only one of these areas, whereas for advanced study and computer simulations, detailed knowledge of the whole task is required. Among the new knowledge and information upon which this article focuses is the evaluation of subsoil stress using specialized pressure cells, along with detailed measurements of the deformation of a fiber-reinforced concrete slab. From a design point of view, this research is focused on the issue of the center of the cross section and the influence of eccentricity. Knowledge in this area is not yet comprehensively available for fiber-reinforced concrete slabs, where 2D deformation sections of the slab and 3D deformation surfaces of the slab are used in experiments. The experimental program includes a centrically and eccentrically loaded slab. These are structural elements that were tested on a specialized device. Both slabs had the same concrete recipe, with a dispersed reinforcement content of 25 kg/m3. The dimensions of the slab were 2000 × 2000 × 150 mm. Laboratory tests assessed compressive strength, the modulus of elasticity, splitting tensile strength, and bending tensile strength. Based on approximate data from the 3D deformation surfaces, an evaluation of the load-displacement diagrams for the center of the slab and for the center of eccentricity was performed. In conclusion, an overall evaluation and discussion of the results relies on experiments and the mechanical properties of fiber-reinforced concrete.

scholarly journals Comparison of Predicted and Experimental Behaviour of RC Slabs Subjected to Blast using SDOF Analysis

2018 ◽  
Vol 68 (2) ◽  
pp. 138 ◽  
Author(s):  
F. B. Mendonca ◽  
G. Urgessa ◽  
K. Iha ◽  
R. J. Rocha ◽  
J.A.F.F. Rocco
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Experimental Program ◽  
Reinforced Concrete Slab ◽  
Peak Displacement ◽  
Blast Damage ◽  
Reinforced Concrete Slabs ◽  
Military Facilities ◽  
Rc Slabs ◽  
Sdof Analysis

<p>Explosions emanating from terrorist attacks or military weapons cause damage to civilian and military facilities. Understanding the mechanical behaviour of reinforced concrete structures subjected to blast is of paramount importance for minimizing the possible blast damage. A full-scale experimental program consisting of six reinforced concrete slabs with compressive strengths of 60 MPa, 50 MPa and 40 MPa, measuring 1.0 m × 1.0 m × 0.08 m, and subjected to 2.7 kg of non-confined plastic bonded explosive, was conducted in blast test area of Science and Technology Aerospace Department (Brazilian Air Force). This paper compares experimentally measured peak displacement values with theoretical values. Theoretical analysis was carried out using single degree of freedom (SDOF) models. The comparison showed that SDOF analysis worked very well in predicting the reinforced concrete slab peak displacement against blast effects. Qualitative analysis after the experiments showed that the blast wave shape generated by the cylindrical explosive was not uniformly distributed on the slabs for the standoff distance of 0.927 m∕kg1/3.<br /><br /></p>

Comparison of steel strength retention models for fire exposed concrete slabs

2021 ◽  
Author(s):  
Thomas Thienpont ◽  
Ruben Van Coile ◽  
Robby Caspeele ◽  
Wouter De Corte
Keyword(s):  
Reinforced Concrete ◽  
Construction Materials ◽  
Structural Response ◽  
Bending Moment ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Moment Capacity ◽  
Retention Models ◽  
Reinforced Concrete Slabs ◽  
Strength Retention

<p>In structural fire engineering, there is a growing trend towards the use of performance based approaches to evaluate structural behaviour during or after a fire. Consequently, there is a need for an increased level of confidence in properties of construction materials used in these performance based approaches. Both steel and concrete have been experimentally observed to show a dispersal in the value of their respective structural strengths, at room temperature, but more significantly at high temperatures. In this paper the influence of three temperature dependent strength retention models for reinforcement steel on the bending moment capacity of simply supported reinforced concrete slabs exposed to a standardized fire is analysed. The results show that the structural response of reinforced concrete slabs strongly depends on the chosen probabilistic model, thus highlighting the importance of appropriate model selection.</p>

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