Splice Sleeve Classroom and Shop Manuals

Question: Discuss about theSplice Sleevefor Classroom and Shop Manuals. Answer: Introduction The splice sleeve is a coupler used for compression pre-cast, tilt up and other similar connections. The splice sleeve connectors are very effective for column-to-footing and column-topier cap bridge assembly (Parks et al., 2016). The splice sleeve coupler has proved its durability against earthquakes over the years. Splice sleeve coupler is connected between the prefabricated concrete. It provides great construction tolerance and load transfer mechanism (Amelia et al., 2016). Research has demonstrated that splice sleeve couple provides durability and increases the displacement ductility of the structure. The report discussed the benefits and complexities associated with the coupler. The paper is based on research of literature and practical examples. Innovation of Splice Sleeve (why it is used in Civil Construction Projects) Splice sleeve was innovated in the late 1960s and has been in use in the civil engineering sector for over the past 40 years. The first innovation was done in the USA before it spread to japan and all over the world. Splice sleeve is used in civil engineering because of its high-performance properties. Due to this property, no fatalities have been reported related to the application of this device(Pickerill, 2017, p. 241). It is used I buildings to withstand the deformations and stresses resulting from earthquakes. Design of Splice Sleeve The design of s splice sleeve can best be demonstrated by taking the example of NMB splice sleeve. The NMB splice sleeve is one of a mechanical coupler used in the splicing of reinforcing bars that applies a sleeve which is cylindrical in shape. The cylindrically shaped steel is filled with cement on the basis of high early strength grout. From this step, the reinforcing bars which are to be spliced are entered into the sleeve. These reinforcing bars are inserted in such a way that they converge at almost the sleeve centre. SS Mortar is then used in filling the interior of the sleeve. It is also important to note that SS Mortar is the only grout acceptable grout as certified by SSNA as conforming to the requirements and standards to be used in splice sleeves under ICC-ESR 3433. There are two codes used as guides in the design of splice sleeves i.e. ACI 318-08(IBC-2006, UBC-970), Type 1 and 2. According to type 1, the specified mean rebar point should be a minimum of 125%. On the other hand, for the case of type 2, ACI31808 provides the guideline in the spacing of the bars for any specified tensile strength of the splice sleeve(Loo, 2009, p. 188). In this type, a specified minimum of 160% of the yield point of rebar can as well be adopted in line with ICBO UBC-97. Importantly, if the splice lies within a moderate to the high seismic region of a plastic hinge joint, then type 2 must be specified. On one end of the precast element, sleeves are embedded at the precast plant. The principal reinforcing bars are inserted midway into the sleeves and the bars are made to protrude from the other end of the precast element. During the construction stage, the precast members that were precast at the precasting plant are joined. This is done through the insertion of protruding bars from the end of the precast element into the sleeves of the adjacent member. This is followed by grouting of the sleeves thereby creating a continuity of the reinforcing bars throughout the connection. This process is called emulation and the splice sleeve made through this process is known to be an emulative connection for precast systems. Strength of Splice Sleeve Splice sleeves have both compressive and tensional strengths which are above the minimum provisions by ASTM A706 and A615. The strength is achieved through embedding the sleeve bars to one end of the precast elements after the precast(Pickerill, 2017, p. 216). The material components are partly a reason for the consistency excellent performance including steel. Durability of Splice Sleeve Due to their high strength and ability to withstand both compressive and tensile forces, splice sleeves are very durable and can be used for a long duration. By embedding sleeve bars into precast elements, a stronger and more durable structure is formed. Splice sleeves have been made even more durable by fabrication and design of mechanical splices. These splices are made by modifying the conventional steel pipes with steel spiral reinforcement, bolts, steel bars which are straight and tapered shapes which improve the strength of the bond and the confinement pressure. Still, some sleeve spices are made of hollow sections square in shape, aluminium tubes besides polymer reinforced with fibre instead of the cylindrical steel pipe initially used in the splice region. These modifications aid in the elimination of the spread of splitting cracks in the grout (mechanical locking material) around bars of steel. All these end up in increasing the overall strength of splice sleeves and hence the durability. Uses of Splice Sleeve Due to their high performance in the provision of solid support for the structure, splice sleeves find their applications in: Retaining walls Concrete Barge Sound Barrier walls Concrete box culvert; and Caisson In all these above applications, the strength and durability form the basis of the preference of sleeve splice (Amelia et al., 2016). Merits and Demerits of Splice Sleeve Merits Include: High compressive and tensile strength: Slip sleeves take advantage of the mechanical gripping of the reinforcing bars and the slip-bond resistance of the grout to achieve maximum tensile strength. In such a setup, the grout serves to be the medium of transfer of load as well as the bonding material between sleeves and bars. High durability: as a result of the high tensile and compressive strengths and the nature of the materials used in the design of splice sleeves their durability is highly enhanced. High stiffness of the components: Steel, hollow square sections and aluminum tubes and Portland cement which are the main materials used in the design of slip sleeves are very stiff hence able to withstand external forces which would otherwise lead to breakage and therefore failure of the system. Saves time as it is quick to assemble: The design of slip sleeves involves not only a few components but also simple components. The simplicity of the components extends to the simplicity with which the assemblage is done. It basically involves inserting the reinforcing bars into sleeves and protruding it from the other end of the already precast elements. The bars are joined adjacent to each other and then reinforced for continuity. High performance: for over the 40 years since slip sleeves were first deployed in the construction, there have not been any reported serious cases of failure of systems built on them. Instead, excellent and high-quality performances have been recorded thereby the reason for the continued increase in the popularity and use of the material. Disadvantages Costly construct splice sleeves: The construction of splice sleeves involve two stages which occur at different places i.e. precasting of elements done at the precasting plant and the actual design and assemblage of the sleeves which is done at the construction stage/industry. Can easily shrink under bad environmental conditions hence proper storage against environmental hazards is required. The sleeves must be kept away from extra heat to maintain its usefulness. This makes it quite challenging to be used in regions with hot and dry climates. Requires proper management of slack to avoid any future connectors damage. An omission of such care would lead to considerable design failures. References Parks, J., Papulak, T., Pantelides, C. (2016). Acoustic emission monitoring of grouted splice sleeve connectors and reinforced precast concrete bridge assemblies. Construction and Building Materials, 122, 537-547. doi:10.1016/j.conbuildmat.2016.06.076 Ameli, M. J., Brown, D. N., Parks, J. E., Pantelides, C. P. (2016). Seismic column-to-footing connections using grouted splice sleeves. ACI Structural Journal, 113(5), 1021-1030. doi:https://dx.doi.org/10.14359/51688755 Loo, G. K. (2009). Parametric Study of Grout-filled Splice Sleeve Integrated with Flexible Aluminium Tube for Precast Concrete Connection. Louis: Universiti Teknologi Malaysia. Pickerill, K. (2017). Today's Technician: Automotive Engine Performance, Classroom and Shop Manuals, Spiral bound Version. New York: Cengage Learning.