scholarly journals The experimental investigations of RC internal columns in the connection zone with lightweight concrete slab

2013 ◽  
Vol 12 (1) ◽  
pp. 187-194
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn ◽  
Łukasz Krawczyk
Keyword(s):  
Lightweight Concrete ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Variable Parameter ◽  
High Strength ◽  
Shear Capacity ◽  
Punching Shear ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Load Carrying

This paper presents the problem of load carrying capacity of the columns made of high-strength reinforced concrete which are separated by slab made of lightweight concrete. The experimental investigations of three models representing the internal connection between column and flat slab made of lightweight concrete of the strength tree times less than concrete strength of column are presented. The effort degree on the punching shear capacity stands for the variable parameter in the presented study. The performed study shows that there is no effect of this parameter on the effective concrete strength of the column.

Composite Constructions of Timber and High-Performance Concrete

2010 ◽  
Vol 133-134 ◽  
pp. 1171-1176
Author(s):  
Hubertus Kieslich ◽  
Klaus Holschemacher
Keyword(s):  
High Performance ◽  
Lightweight Concrete ◽  
High Performance Concrete ◽  
Concrete Slab ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Experimental Investigations ◽  
Hardened Concrete ◽  
Timber Beam ◽  
Load Carrying

Currently Timber-Concrete Composite (TCC) Constructions are often applied for strengthening existing timber beam slabs. The load bearing capacity of the composite construction is primarily affected by the material properties of the timber beam and the concrete slab. But the type of bond between both parts is also of high importance. The concrete slab has to perform several tasks, not only in load carrying direction of the ceiling but also perpendicular to the direction of span or for stiffening the whole building. These tasks will be pointed out in this paper. Furthermore the working process (easy workable mixture and exchange of conventional reinforcement) and the dead load of the construction are of particular interest in the field of redevelopment. Several innovative concretes have been verified for the use in TCC constructions. Regarding their fresh and hardened concrete properties, they all can be described as High Performance Concretes (HPC). In this paper Self Compacting Concrete (SCC), Fiber Reinforced Concrete (FRC), Structural Lightweight Concrete (SLWC), High Strength Concrete (HSC) or combinations of them will be focused. Especially the advantages but also the disadvantages of innovative concretes for the use in TCC will be presented as well as the results of some experimental investigations.

scholarly journals Experimental investigations of reinforced concrete columns in the edge connection zone with a reinforced concrete slab

2014 ◽  
Vol 13 (3) ◽  
pp. 175-182
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn ◽  
Łukasz Krawczyk
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Variable Parameter ◽  
High Strength ◽  
Concrete Columns ◽  
Experimental Investigations ◽  
Reinforced Concrete Slab ◽  
Strength Concrete ◽  
High Strength Concrete Columns

In this paper the results of the experimental investigations of edge column – slab connections are presented and commented on. The load transmission mechanism between high strength concrete columns and slab made of normal, five times lower strength concrete was considered. The variable parameter of presented study was the overhang of slab cantilever. The performed study showed important effect of slab cantilever on effective concrete strength of column in the connection zone.

Punching shear analysis of reinforced high-strength concrete slabs

1991 ◽  
Vol 18 (6) ◽  
pp. 954-963 ◽  
Author(s):  
H. Marzouk ◽  
A. Hussein
Keyword(s):  
Mechanical Model ◽  
High Strength Concrete ◽  
Concrete Slab ◽  
High Strength ◽  
Shear Capacity ◽  
Punching Shear ◽  
Strength Concrete ◽  
Modes Of Failure ◽  
Proposed Model ◽  
Memorial University Of Newfoundland

An experimental investigation was conducted at the structural laboratory at Memorial University of Newfoundland to examine the behaviour of high-strength concrete two-way slabs. It was evident that a new mechanical model is required to predict the punching shear capacity of such slabs. The experimental results of the tested slabs with regard to deformations, strains, ultimate capacity, and modes of failure were examined. Based on the test results, a mechanical model was adopted and developed for high-strength concrete slab applications. The formulation takes into account the actual behaviour of the high-strength concrete and steel. The proposed model gives a fairly good agreement between the predicted and experimental punching loads. Key words: deflections, deformations, failure mechanisms, flat concrete plates, high-strength concrete, loads (forces), mechanical model, punching shear, reinforced concrete.

scholarly journals Effect of Use Recycled Coarse Aggregate on the Behavior of Axially Loaded Reinforced Concrete Columns

2019 ◽  
Vol 25 (10) ◽  
pp. 88-107
Author(s):  
Omar Shamal Farhan
Keyword(s):  
Carrying Capacity ◽  
Coarse Aggregate ◽  
Concrete Strength ◽  
Steel Fibers ◽  
Environmental Benefits ◽  
Recycled Aggregates ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Axially Loaded

Nowadays, the use of recycled waste construction materials instead of aggregates is becoming popular in construction owing to its environmental benefits. This paper presents an experimental and analytical campaign to study the behavior of axially loaded columns constructed from recycled aggregates. The latter was used instead of natural aggregates, and they were collected from the waste of previous concrete constructions. Different concrete mixtures made from varying amounts of recycled aggregates ranged from 0 to 50% of the total coarse aggregate were conducted to achieve 28 MPa. The effect of steel fibers is another investigated variable with volumes ranged from 0 to 2% concerning concrete’s mixture. The experimental results showed that the concrete strength is dependent on the amount of recycled aggregates. When the recycled aggregates were less than 30% of the total aggregates, they had a negligible effect on concrete strength and the load carrying capacity of the column models were improved. Also, the presence of steel fibers enhanced the load carrying capacity of the columns constructed from concrete with recycled aggregates of more than 30%. Finite element analysis (using ANSYS 16.1 software program) was conducted to simulate the experimental investigations, and they achieved good agreements with the test results.

Shear strengthening of reinforced concrete beams with high-strength steel wire and engineered cementitious composites

2021 ◽  
pp. 136943322110463
Author(s):  
Fang Yuan ◽  
Wangren Wei ◽  
Ren Hu
Keyword(s):  
Shear Strength ◽  
Carrying Capacity ◽  
Steel Wire ◽  
High Strength ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Load Carrying Capacity ◽  
Cementitious Composite ◽  
Shear Strengthening ◽  
Load Carrying

Engineered cementitious composite (ECC) is a type of high-performance fibre-reinforced cementitious composite with good ductility and excellent crack control ability. It has attracted increasing attention as a structural repair material in severely corrosive environments. However, the strength improvement is limited when ECC is used alone for shear strengthening of existing reinforced concrete (RC) members, although its shear capacity is much higher than that of other brittle cementitious materials such as cement mortar. This study proposes a novel shear strengthening method for RC beams with both high load-carrying capacity and good durability through the combination of high-strength steel wire and an ECC layer. The shear behaviours of the beams were tested under static loading. The test results showed that the shear strength and the ultimate displacement were significantly improved through shear strengthening. A large number of fine cracks appeared on the ECC layer before the failure of the beams. The load-carrying capacity was reduced by pre-damage owing to the important role of the shear resistance of the concrete with respect to the total shear capacity. The shear strength of the strengthened beams cannot be accurately predicted by the current design code owing to the ignorance of the shear resistance of ECC.

scholarly journals Experimental Investigations on Punching Shear of Flat Slabs Made from Lightweight Aggregate Concrete

2018 ◽  
Vol 64 (4) ◽  
pp. 293-306 ◽  
Author(s):  
M. Gołdyn ◽  
Ł. Krawczyk ◽  
W. Ryżyński ◽  
T. Urban
Keyword(s):  
Lightweight Concrete ◽  
Variable Parameter ◽  
Lightweight Aggregate ◽  
Reinforcement Ratio ◽  
Punching Shear ◽  
Lightweight Aggregate Concrete ◽  
Experimental Investigations ◽  
Concrete Slabs ◽  
Aggregate Concrete ◽  
Flat Slabs

Abstract In the paper the results of experimental investigations concerning flat slabs made from reinforced lightweight concrete with sintered fly ash aggregate CERTYD were presented. In the research program 6 models made in a natural scale were included. The main variable parameter was slab longitudinal reinforcement ratio. The aim of investigation was the experimental verification of efficiency of double-headed studs as punching shear reinforcement. In the existing technical approvals such kind of reinforcement was allowed only in normal concrete slabs. It was demonstrated that double-headed studs can be an effective transverse reinforcement of lightweight aggregate concrete slabs. The use of double-headed studs resulted in increase in the ultimate load from 19% to 44%, depending on the slab reinforcement ratio which ranged from 0.5% to 1.2%. The comparative analysis showed that the Eurocode 2 provisions were conservative in relation to the experimental results, which were on average 42% higher than the theoretical ones however with a very low 7% coefficient of variation.

scholarly journals Experimentally Validated Numerical Analysis of Reinforced Concrete Slab-Column Connections Subjected to Punching Shear

2020 ◽  
Vol 10 (2) ◽  
pp. 125-132
Author(s):  
S.C. Floruț ◽  
D.A. Popescu ◽  
V. Stoian ◽  
D. Daniel ◽  
T. Nagy-György ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Numerical Modelling ◽  
Concrete Slab ◽  
Maximum Load ◽  
Shear Capacity ◽  
Experimental Investigations ◽  
Reinforced Concrete Slab ◽  
Finite Element Software ◽  
Flat Slabs ◽  
Load Carrying

AbstractThe paper presents the results of experimental investigations and numerical analyses performed on reinforced concrete flat slabs. Two tests were carried out on two flat slab specimens designed without specific shear reinforcement. The present paper deals only with the experimental behaviour and numerical modelling of such slabs, this representing the initial part of a larger study which aims to evaluate the shear capacity of such deficient slabs resulted from faulty design or execution and to identify viable and efficient strengthening solutions. ATENA finite element software package was used to numerically model the behaviour of the specimens. A very good agreement was achieved between the results of experimental investigations and numerical modelling with deviations of 0.2% in terms of maximum load carrying capacity and of 7% in terms of corresponding displacement. The specimens were able to carry loads of more than 950kN, larger than those evaluated using designated Eurocodes, displaying a safety factor of 2.72.

scholarly journals Analysis of Ultimate Load-Carrying Capacity of Combined Connection with Bolts and Welds

Mechanika ◽  
2019 ◽  
Vol 25 (6) ◽  
pp. 426-433 ◽  
Author(s):  
Tao LAN
Keyword(s):  
Ultimate Load ◽  
High Strength ◽  
Shear Plane ◽  
Deformation Capacity ◽  
Load Carrying Capacity ◽  
Element Calculation ◽  
Lap Splices ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Longitudinal Welds

In this paper, load-carrying and deformation capacity of tension lap splices that have both welds and bolts acting in the same shear plane are studied using numerical method. The failure criterion of bolts and welds are given based on the finite element calculation and compared with existing experiment results, it shows that the established numerical model is correct and reliable. The strength of longitudinal welds and the bearing capacity of the high-strength bolts before slipping can be fully used in the combined joints, the bolts and welds fail almost simultaneously. The deformation of welds in combined connections is less uniform than its’ deformation in welded joints as the welds fails, and it causes the deformation of welds as failure is larger in combined connections than in welded connections. The deformation capacity of the combined joint are slightly increased contrasted with bolts joint and welds joint because of the interplay of bolts and welds acting in the same shear plane. The strengths of welds and bolts performed in combined connections can reach 0.95 and the deformation of combined connection is increased at least 1.10 times as the welds connection or the bolts connection.

scholarly journals Strengthening of Reinforced Concrete Beams Subjected to Concentrated Loads

2022 ◽  
Author(s):  
Paolo Foraboschi
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Reinforced Concrete Structure ◽  
Concentrated Loads ◽  
Concentrated Load ◽  
Load Carrying

Renovation, restoration, remodeling, refurbishment, and retrofitting of build-ings often imply modifying the behavior of the structural system. Modification sometimes includes applying forces (i.e., concentrated loads) to beams that before were subjected to distributed loads only. For a reinforced concrete structure, the new condition causes a beam to bear a concentrated load with the crack pattern that was produced by the distributed loads that acted in the past. If the concentrated load is applied at or near the beam’s midspan, the new shear demand reaches the maximum around the midspan. But around the midspan, the cracks are vertical or quasi-vertical, and no inclined bar is present. So, the actual shear capacity around the midspan not only is low, but also can be substantially lower than the new demand. In order to bring the beam capacity up to the demand, fiber-reinforced-polymer composites can be used. This paper presents a design method to increase the concentrated load-carrying capacity of reinforced concrete beams whose load distribution has to be changed from distributed to concentrated, and an analytical model to pre-dict the concentrated load-carrying capacity of a beam in the strengthened state.

scholarly journals The Assessment of Using CFRP to Enhance the Behavior of High Strength Reinforced Concrete Corbels

2021 ◽  
Vol 28 (1) ◽  
pp. 71-83
Author(s):  
Mazin Abdulrahman ◽  
Shakir Salih ◽  
Rusul Abduljabbar
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Strength ◽  
Load Capacity ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Ultimate Load Capacity ◽  
Load Carrying ◽  
Externally Bonded ◽  
Effective Depth

In this research, an experimental study is conducted to investigate the behavior and strength of high strength reinforced concrete corbels externally bonded with CFRP fabric sheets and Plates with different patterns taking into account the effect of adopted variables in enhancing the ultimate strength; the effect of shear span to effective depth (a/d), configuration, type and amount of bonding. Eleven high strength reinforced corbels were cast and tested under vertical loads. Test results showed there was an improvement in the behavior and load carrying capacity of all strengthened corbels. An increasing in the ultimate strength of strengthened corbel by inclined CFRP strips reached to (92.1%) while the increasing reached to (84.21%) for using one horizontal CFRP Plates compared to un-strengthened reference specimen. Also, it can be conducted that the increase of (a/d) ratio from (0.6 to 0.8) resulted in decreasing by 21.05% in ultimate load capacity of corbels and from (0.4 to 0.6) by 31.25% and 58.69% in cracking and ultimate loads respectively Using CFRP .

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