Comparative study of factors influencing tension lap splices in reinforced concrete beams (original) (raw)
Related papers
IMPROVING THE BEHAVIOR OF REINFORCED CONCRETE BEAM WITH VARYING LAP SPLICES LENGTH
The main objective of this paper is to study the behaviour of lap splice of steel reinforcement in tension zones in reinforced concrete beams. An experimental program is conducted on fifteen simply supported concrete beams. The main studied variable is splices length in the splice zone. There is an increase in ductility of beams when transverse reinforcement was used.
Assessment on Tension Bar Lap Splices of Concrete Reinforcement Steel
Splicing rebar with lap splices must be done in its implementation due to the influence on the methods of implementation and the availability of existing reinforcing steel length. Lap splices length (ld) serves to channel the force borne by the steel reinforcement. Lap splices length testing conducted to determine the distribution of force occurs. The test specimen lap splice using a class B which is 1.3 ld with concrete covers at least 3 cm. By using an experimental study in which the use of reinforcing steel D-10 with a lap splices length of 1.3 ld by 43 cm, 1.2 ld by 40 cm using K-400 concrete and calculation analysis produces the lap splices length 27 cm and 30 cm use quality of concrete K-400 and K-450. Tests using the tensile test equipment (Universal Testing Machine) in laboratory B2TKS BPPT. Results from this study is the length of the lap splices of 1.3 ld and 1.2 ld use quality of concrete K-400 is able to meet the mechanical properties of reinforcing steel for the collapse occurred in the reinforcing steel. With lap splices length 27 cm and 30 cm using quality of concrete K-400 occur in lap splice collapse after passing the yield stress of reinforcing steel 40 kg/mm 2. While the lap splices length 27 cm and 30 cm using the quality of concrete K-450 collapse there are a difference between the test specimens due to the tension that occur closer to the ultimate stress of rebar's at 57 kg / mm 2
REVIEW OF DESIGN CODES FOR TENSION SPLICE LENGTH FOR REINFORCED CONCRETE MEMBERS
Institution of Engineers, Bangladesh., 2013
A review of provisions of different design codes for splice lengths of reinforcing bars used in reinforced concrete structures has been presented. The reviewed codes are ACI (2002), BNBC (1993), AASHTO (2007), CEB-FIP Model (1990) and EURO Code 2(2003). Normalized splice length is calculated for particular strength of concrete and reinforcing bars. A parametric study has been conducted for selected parameters. It has been found from the study that for BNBC (1993), the normalized splice length remains the same up to 22 mm diameter bars and for larger diameter bars the normalized splice length increases significantly. In contrast, ACI (2002) recommends the same normalized splice length for 22 mm and larger diameter bars. CEB-FIP Model (1990) advised the larger normalized splice length than ACI (2002) for lower strength of concrete. With increasing of concrete strength CEB-FIP Model exhibits the largest normalized splice length.
Performance of Tension Lap-Splice in Lightweight Concrete
International Journal of Engineering and Advanced Technology, 2020
The use of Light-Weight Concrete (LWC) in modern construction has resulted in efficient designs and considerable cost savings by reducing structural own weight and supporting footings sections. The purpose of this paper is to investigate the Lap-Splice behavior between LWC and steel reinforcement (RFT). The tested specimens were divided into four groups to study the effect of main variables: steel reinforcement bar size, internal confinement (stirrups), splice length and concrete cover thickness. Four-point bending tests were carried out on test specimens to evaluate the performance of lap splices under pure bending. Bond behavior and failure modes were noted to be similar in the normal concrete and in the LWC. In tested beams, it was observed that the bar size has a significant influence on the mean bond stress in the splice. Improving radial tensile strength by using increasing stirrups number improves the bond behavior. The splice length up to 35 times bar diameter decreased the ...
Materials and Structures, 2002
Reports on the very brittle and splitting mode of failure of tension lap splices anchored in high strength concrete (HSC) specimens and the lower normalized bond stress [u/~) for high strength than for normal strength concrete, instigated several research projects aiming at recommending mechanisms to provide confinement and ductility for bars or splices anchored in HSC. The stateof-the-art report of ACI Committee 363, ACI 363R-84, defines high strength concrete as concrete with compressive strength above 6,000 psi (41.4 MPa).
2013
The aim of this research is to study flexural behaviour rectangular concrete beams with lap splice between deformed and smooth bars. An experimental program has been performed to investigate the research point, where sixteen rectangular concrete beams were tested in a four point bend configuration. Specimens were grouped into four groups to investigate influences of lap splice length, stirrups intensity and location, end shape, and concrete characteristic strength (N.S.C and H.S.C). It was concluded that distributing stirrups along the splice length increase failure load more than concentrating them at splice ends; end shaping of splices increases failure load; Increasing splice length compared with that required for transmission of tensile stresses through bond decreases ductility; linearity of strain distribution along reinforcement bars increase by the increase and uniformity of stirrups confinement; increasing splice length decreases the difference between strain in deformed and smooth bars.
Tension Lap Splice Length of Reinforcing Bars Embedded in Reactive Powder Concrete (RPC)
Structures, 2019
Reactive Powder Concrete (RPC) is an emerging cementations construction material which has superior mechanical properties such as high compressive and tensile strength, high density and homogeneous. In this research, the tension splice behaviour of reinforcement bars embedded in RPC was investigated using experimental and numerical studies. Six reinforced RPC beams with four-point loading were tested. The parameters investigated in the experimental program were steel fibre contents, size of reinforcing bar, tension reinforcement splice length, and amount of transverse reinforcement. The experimental findings showed that the increasing of steel fibre content, amount of transverse reinforcement, length of spliced bars, and diameter of spliced bars increased the tension splice strength of steel bras embedded in RPC members. Splitting of concrete is the dominate mode of failure that occurred in RPC beams spliced with tension reinforcement. Finite element method was used in this study to simulate the behaviour of members tested experimentally and a comparison between experimental and numerical results were conducted. The comparisons showed a good agreement between experimental results and numerical results in terms of load deflection curves and splice strengths. The verified finite element model was used then to study the effect of wide range of data for variables affect the splice strength using a parametric study. A proposed design equation of splice strength of tension reinforcing bars embedded in RPC was proposed in this study and verified with numerical results.
ACI Structural Journal, 2005
Criteria recommended by ACI Committee 408 on development and lap splice length design for straight reinforcing bars in tension are presented in code format and compared with those in ACI 318-05, Building Code Recommendations for Structural Concrete. The recommended criteria produce designs with improved reliability compared to those in ACI 318. Development lengths are longer than those in ACI 318 for conditions of low cover or confinement, but shorter for bars with higher degrees of confinement, provided by added cover and transverse reinforcement and wider spacing between bars, and for normalweight concretes with strengths between 10,000 and 16,000 psi (70 and 110 MPa). This paper is sponsored by ACI Committee 408, Bond and Development of Reinforcement.
Effect of tension lap splice on the behavior of high strength self-compacted concrete beams
Construction using concrete is spreading widely and there is a need for concrete that is capable of flowing under its own weight without mechanical vibration or compaction and fill the places between reinforcement and the complicated form shapes. From here, Self-Compacted Concrete (SCC) appears for the first time. Limited attention has been directed toward the bond between High Strength Self-Compacted Concrete (HSSCC) and spliced bars in beams [1–8]. This research studies the bond between HSSCC and spliced tension bars in beams. It is focused on observing the effect of some factors such as; reinforcement bar diameter and ratio, splice length and casting position on the beam flexural behavior. An experimental program consisting of sixteen simply supported beams divided into four groups is considered. All beams are of 1800 mm span and 200 · 400 mm cross-section cast with HSSCC. In twelve beams, the tensile steel was spliced in the constant moment zone, and four control beams without splice for comparison purpose. During testing; ultimate capacity, deflection, crack pattern and mode of failure have been recorded. Test results had been compared with proposed values in the Egyptian code of practice, other international design codes and recorded values of other researchers.
Techniques Used for Bond Strengthening of Sub-Standard Splices in Concrete: A Review Study
Processes
Bar splicing is considered an essential part of the construction process of reinforced concrete (RC) due to the ease of installation in construction, transportation constraints, and restricted length of reinforcing bars. Splices serve the primary role of joining reinforcement bars in standard RC elements such as columns, walls, beams, slabs, and joints. Bond behavior between the bars and the concrete is one of the fundamental qualities required for appropriate RC structure design and analysis, as it affects serviceability and ultimate limit states. The most common failure found in lap splice locations is debonding, which occurs at the splice region and insufficient lapped length is considered as the primary cause because of design or construction mistakes, design by outmoded code, and natural catastrophes. As a result, strengthening existing substandard splices in RC structures is critical. The purpose of this research is to analyze and summarize experimental strengthening solutions...