Sprayed-On Polymer as Concrete Spall Shield

2008 ◽  
Vol 136 ◽  
pp. 145-152 ◽  
Author(s):  
Bryan Lim ◽  
Pei Jun Hong
Keyword(s):  
High Velocity ◽  
Numerical Models ◽  
Concrete Slab ◽  
Thick Layer ◽  
Polymeric Coating ◽  
Test Results ◽  
Reinforced Concrete Slab ◽  
Concrete Panels ◽  
Opposite Face ◽  
Simulation Results

Concrete when subjected to a blast loading from a close-in detonation will experience spalling due to formation of tension waves on the opposite face of the concrete panel. The spalled concrete may be ejected at high velocity causing undesirable effects to occupants. Tests using 1/2kg TNT blocks were conducted on 100mm thick concrete panels to study the effects of spalling and whether the spalled materials can be arrested using a sprayed-on polymeric coating. From the tests, it was observed that without the sprayed-on polymeric coating, extensive spalling occurred. However, with just a 3-4mm thick layer of sprayed-on polymer, the spalled materials were arrested and contained. Numerical models of the reinforced concrete slab were created using Autodyn 2D and the results of the simulation were compared to observations from the tests. There was good correlation between the test results and the simulation results as the size of the crater, both front and back, on the concrete slab were rather similar.

Simulation of a Reinforced Concrete Slab Punching Impact

2012 ◽  
Author(s):  
Jukka Kähkönen ◽  
Pentti Varpasuo
Keyword(s):  
Reinforced Concrete ◽  
Impact Velocity ◽  
Concrete Slab ◽  
Test Results ◽  
Concrete Wall ◽  
Reinforced Concrete Slab ◽  
Simply Supported ◽  
Blind Prediction ◽  
Reinforced Concrete Wall

Reinforced concrete wall subjected to an impact by a hard steel missile with a mass of 47 kg and an impact velocity of 135 m/s was one case study in the IRIS 2010 benchmark exercise in OECD/NEA/CSNI/IAGE framework. The wall had dimensions of 2m × 2m × 0.25m and it was simply supported. The perforation of the missile was expected. Fortum Power and Heat Ltd. participated in the benchmark. In this paper, we present our modeling and blind prediction of the benchmark case. The test results of the benchmark were released after the predictions were made. Based on the result comparison, we concluded that our model gave conservative results.

Flexural Behavior of Void Reinforced Concrete Slab with CFRP Reinforcing Bars

2012 ◽  
Vol 184-185 ◽  
pp. 988-991
Author(s):  
Seung Hun Kim
Keyword(s):  
Concrete Slab ◽  
Flexural Behavior ◽  
Test Results ◽  
Compression Zone ◽  
Reinforcing Bars ◽  
Flexural Capacity ◽  
Reinforced Concrete Slab ◽  
Bending Tests ◽  
Bending Performance ◽  
Flexural Members

Use of hollow material in slab can reduce self-weight and deflection than solid slab with CFRP reinforcement. This study was intended to evaluate the bending performance of void flexural members with CFRP reinforcements by bending tests. Test results showed that specimens with void and solid section had the similar failure mode by concrete crushing at the compression zone, and that there was a big flexural capacity difference between the two section. Flexural capacity of solid section with CFRP bars was increased by 55% for void section. Thus, for the design of flexural members with CFRP bars by concrete crushing failure, it is important to calculate the exact distribution of strains and stresses, and to consider the reduction of flexural strength of void section.

The Experimental Study of Ultrasonic Testing Prestressed Bellows Pore Grouting Quality

2014 ◽  
Vol 711 ◽  
pp. 461-468 ◽  
Author(s):  
Shao Lin Zhou ◽  
Feng Zhang ◽  
Yuan Cao
Keyword(s):  
Experimental Study ◽  
Ultrasonic Testing ◽  
Concrete Slab ◽  
Ultrasonic Method ◽  
Test Results ◽  
Concrete Panels ◽  
Head Waves ◽  
Different Thickness ◽  
Regular Patterns

The ultrasonic method can be used for testing and analyzing the pore size of concrete. By studying the spectrum curves which is formed by ultrasonic transmitting at different thickness concrete panels can we get different time regular patterns of head waves formed by ultrasonic going through homogeneous concrete, compact grouting pore, grouting incompact pore, not grouting pore. All these provide a basis for predicting prestressed bellows pore grouting quality and judging whether there is interspace in pore. By artificially setting defects in bellows pore, for example, filling the pore to completely empty, 1/4 compact, 1/2 compact, 3/4 compact, fully compact and then embedding them in a concrete slab for ultrasonic testing. Test results show that the ultrasonic method can effectively evaluate the grouting quality of prestressed bellows pore.

Behavior of Two-way RC Slabs Combination Strengthened with CFRP Strips and Steel Sheets

2014 ◽  
Vol 501-504 ◽  
pp. 1048-1052 ◽  
Author(s):  
Xiao Jin Li ◽  
Yi Yan Lu ◽  
Na Li
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Test Results ◽  
Reinforced Concrete Slab ◽  
Steel Sheets ◽  
Reinforced Concrete Slabs ◽  
Rc Slab ◽  
Rc Slabs ◽  
Strengthening Technique

A total of four two-way reinforced concrete slabs strengthened with three methods were tested. The four test specimens were one unstrengthened reinforced concrete slab (control), one slab strengthened with CFRP strips, one slab strengthened with steel sheets, and one slab strengthened with an innovative method of applying CFRP strips and steel sheets combination bonding to the tension face of the slab. The test results show the CFRP-Steel combination strengthened technique is a rapid and effective strengthening technique for two-way RC slab. The increase in ultimate capacities of CFRP-Steel combination strengthened slab is 221.1% over the control slab, 84.4% over the CFRP-strengthened slab, and 45.2% over the steel-strengthened slab. In addition, the CFRP-Steel combination strengthened slab exhibited superior ductility than the CFRP-strengthened slab.

scholarly journals Optimal Design of Steel–Concrete Composite Beams Strengthened under Load

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4715
Author(s):  
Piotr Szewczyk ◽  
Maciej Szumigała
Keyword(s):  
Numerical Models ◽  
Concrete Slab ◽  
Plate Thickness ◽  
Steel Part ◽  
Composite Beams ◽  
Steel Plates ◽  
Reinforced Concrete Slab ◽  
Recoverable Strain ◽  
Bending Capacity ◽  
Optimum Solution

This paper presents results of numerical analysis and experimental research on strengthening of steel–concrete composite beams. Studied members consisted of IPE200 I-beam and 90 × 700 mm reinforced concrete slab. The steel part of the section was strengthened by welding additional steel plates at the bottom. The study was performed for plate thickness ranging between 6 to 22 mm. Spatial FEM models were developed to account for material and geometric nonlinearities and for stress and post-welding strain. Proposed numerical models were experimentally validated. One aim was to find an optimum solution which would minimize cost and maximize bending capacity. To achieve this, energy parameters available in numerical simulations were reviewed and analyzed. Recoverable strain energy value determined in Abaqus was used to find the optimum solution.

Assessment of CSA A23.3 structural integrity requirements for two-way slabs

2012 ◽  
Vol 39 (4) ◽  
pp. 351-361 ◽  
Author(s):  
Farshad Habibi ◽  
Erin Redl ◽  
Michael Egberts ◽  
William D. Cook ◽  
Denis Mitchell
Keyword(s):  
Reinforced Concrete ◽  
Structural Integrity ◽  
Concrete Slab ◽  
Punching Shear ◽  
Slab Thickness ◽  
Test Results ◽  
Reinforcing Bars ◽  
Reasonable Estimate ◽  
Reinforced Concrete Slab ◽  
Rectangular Columns

This paper investigates the post-punching behaviour of reinforced concrete slab–column connections with a goal of providing adequate structural integrity reinforcement. The test results of seven interior slab–column connections are presented. A study was made of the effects of slab thickness, length of structural integrity reinforcing bars, distribution of structural integrity reinforcement in slabs with rectangular columns, and the placement of structural integrity reinforcement in slabs with drop panels. Results from this test series and other researchers were compared with predictions using the CSA A23.3-04 design equations for both punching shear and post-punching resistance. The test results demonstrated that the provision of structural integrity reinforcement in accordance with the requirements of CSA A23.3-04 resulted in significant post-punching resistance and the design equations provide a reasonable estimate of this resistance.

Evaluation and comparison of concrete constitutive models in numerical simulation of reinforced concrete slabs under blast load

2021 ◽  
pp. 204141962110489
Author(s):  
Hani Mahdavi Talaromi ◽  
Farhad Sakhaee
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Concrete Slab ◽  
Constitutive Models ◽  
Computation Time ◽  
Material Model ◽  
Reinforced Concrete Slab ◽  
Rc Structures ◽  
Reinforced Concrete Slabs ◽  
Concrete Damage

Numerical models have been used recently to analyze concrete structures subjected to high-impulsive loads. A material model that can well capture the mechanical behaviors is crucial to obtain reliable results. Present study, focused on reinforced concrete slab as a major load carrying element of the RC structures under blast loading. By performing several simulations in popular and powerful concrete constitutive models, including concrete damage R3, HJC, CSCM, and Winfrith the accuracy of these models was investigated. Maximum deflections have been compared with each other and expanded further to compare with experiments. Result showed all models have an acceptable accuracy in estimating maximum slab deflection. Concrete Damage R3 presented the highest accuracy. HJC has the second rank and CSCM and Winfrith have the third and the fourth places, respectively. HJC needed the minimum computation time. CSCM had minimum input parameters but includes maximum calculation time. Winfrith had the lowest accuracy, however this model presented very conservative results. Uniaxial compressive and tensile stress-strain curves showed that the models which presented higher values of strength, evaluated lower maximum values of deflection.

Reinforced concrete slab-column edge connections with shear studs

2000 ◽  
Vol 27 (2) ◽  
pp. 338-348 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Monir H Soliman
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Slab ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Reinforced Concrete Slab ◽  
Test Parameters ◽  
Flexural Reinforcement ◽  
Large Scale Tests

The paper reports the results of an experimental investigation on the influence of shear studs on the behaviour of reinforced concrete slab-column edge connections with openings. The test parameters were the location of openings around the column, the size of openings, and the existence of shear reinforcement. The objective of the paper is to present and discuss the results of large-scale tests on slabs with shear stud reinforcement and compare these test results with those of tests on identical slabs but without shear reinforcement. All tested slabs contained same amounts of typical flexural reinforcement (ACI 318-95 and CSA A23.3-94). The presented test results can be used for studying the behaviour of slab-column connections and for calibration of the predictive models.Key words: reinforced concrete, edge connections, flat concrete plates, punching shear, shear strength, openings, failure, shear studs, shear reinforcement.

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