News

With all these catastrophes all around the world, Malaysia has been exposed to the stark reality that we can no longer be considered immune to such tragedies of tragic proportions in terms of lives lost, property destruction and even economic collapse.

The government and regulatory bodies have therefore taken serious steps in reviewing current building regulations and codes, to enable structural engineers and constructors to take immediate and necessary precautions to ensure the safety of their design as they are liable if anything happened to the buildings (refer provisions under CIDB act below).

*MS 2500 (Profile) Enforced 1 December 2016 Consultation with industry and testing body on 5 January 2017: Testing requirements for design requirements are not clearly stated. The meeting agreed to adopt AS4600 and EN9590 Part 5 in addition to MS2500. CIDB has submitted the MS2500 revise application to DSM on January 6, 2017.

MOMENT JT mechanical connections conform fully with applicable codes including BS 8110 Pt 1:1997 Clause 3.12.8.16.2 Bar in Tension and ISO 15835, providing defined ductile behaviour and performing like a continuous reinforcing bar.

Fig 1: MOMENT JT connections perform beyond the yield point of the bar whereas Lap Splices are only defined in the elastic area. This indicates that the MOMENT JT connection which works as a continuous bar provides additional strength and safety all around independent of the quality of the surrounding concrete.

In reinforced concrete design, the Structural Engineer is faced with the task of determining where and how reinforcing bars must be spliced in a structure. This must be done to ensure that the national regulations are adhered to and also to make sure that the structure will not suffer a progressive collapse if overloaded.

Due to the minimum connection strength required, it is generally assumed in design that the occurrence of a mechanical connection of two reinforcing bars does not result in a reduction of the anticipated structural strength nor the longitudinal ductility of the reinforcing steel. This would maintain the properties which the reinforced concrete member would have had with a continuous unspliced bar. That is, it is assumed that the use of a mechanical connection does not introduce a structural weakness that could jeopardize the overall structural performance.

Design requirements of the applicable codes as in BS 8110 and EN 1992-1 generally assume a minimum connection strength but are silent on the details about test methods and conformity assessment. ISO 15835, which is used as the basis for CREAM’s assessment covers all aspects of coupler production and assessment including:

1. To assess the serviceability, a test is made on a representative gauge length assembly comprising reinforcement of the size, grade and profile to be used and a coupler of the precise type to be used, the permanent elongation after loading to 0.6fy should not exceed 0.10mm,
2. It also covers tests for couplers to be used for mechanical splices in reinforced concrete structures under predominantly static loads and additional requirements for couplers to be used in structures subjected to high cycle elastic fatigue loading and/or to low cycle elastic-plastic reverse loading to represent seismic activities.

In a structure undergoing inelastic deformations during an earthquake, the tensile stresses in reinforcements may approach the tensile strength of the reinforcements. The requirements for MOMENT JT mechanical splices are intended to avoid a splice failure when the reinforcement is subjected to expected stress levels in the plastic regions. In addition to that, in plastic hinge regions, the first part to fail is the concrete where excessive spalling occurs. Once the concrete spalls, the lap splice behaviour is severely compromised, whereas the mechanical splice behaviour remains intact.

Lap Splices (2011 – Turkey) – Concrete spalling results in lower or zero capacity as the concrete that is critical in the load transfer has disappeared.

Mechanical Splices (2017 – Mexico City) – Concrete spalling has no effect on capacity as the mechanical connection is still present.

In seismic consideration:

1. MOMENT JT connections promote full strength capabilities and offer in tension more than the specified ultimate strength of the reinforcing bars ensuring that rupture will only occur in the reinforcing bar before failure in the mechanical connection.
2. MOMENT JT connections are manufactured to the exact standards to withstand a breaking strength of more than 700MPa  thereby promoting adequate strength and ductility so that failure initiates in the concrete rather than the steel reinforcements in the event potential inelastic straining may occur during seismic excitation.

MOMENT JT connection offers many advantages to the designer and builder to help improve the design and reduce construction time and cost while providing versatility and can help to solve many construction problems today.

As Malaysia progresses in nation-building, federal governance, regulations and codes for construction regarding seismic frame construction become more stringent, MOMENT JT connections, the proven mechanical splice method, provides you with the ability to design and build concrete structures to withstand the test of time.

Locally Approved Couplers For Quality Connections.
Let Us Drop You A Call For Consultation. For Free.

Name*

Email*

Phone (Please Include Area/ Country Code)*

Area Code

 - 

Phone Number

Word Verification

SubmitReset

Related Products You May Be Interested

With the advent of Industrialized Building System (IBS), there is one aspect of the supply chain that has remained unregulated and subject to risk of poor quality solutions creeping in to the market place that might be structurally unsound. This largely comes from the fact that the metallurgy of these connections is critical to their suitability, so the selection of the right steel is vital to ensure their performance.

Metallurgy plays a crucial role in enabling sustainability

When construction methods changed to IBS, there was a sudden influx of new technologies to assist in the connections of the precast element; but there is a natural lag before product codes can catch up and provide the same level of total robustness as traditional construction methods.

IBS approach has been widely adopted, as it reduces construction time frames compared with conventional methods.

While the scope of BS8110 did not cover all of these new connections, at least there were some minimum requirements for the mechanical splicing of reinforcing bars.

Thankfully, the CIDB in Malaysia realised that there was a gap and has identified CREAM* as a certification body who can provide the same service locally to provide confidence to the users, purchasers and specifiers of constructional steels and to ensure its safety and reliability, government, private and/or non-profit bodies. However, for other more advanced technologies, where no standards exist today, this type of certification is not possible as CREAM needs a standard to audit against.

For these the engineering community needs to better understand the metallurgy and ensure that the products are fit for purpose. But at least for mechanical splices, the publication of ISO 15835:2018 means that CREAM certification is now possible.

*The Construction Research Institute of Malaysia (CREAM) is a research and development (R & D) institution for the construction industry in Malaysia. Committed to ensure that R & D programs meet the needs and requirements of the national construction industry by implementing quality management systems that meet MS ISO 9001.

Related Articles You May Be Interested

The East Coast Rail Link (ECRL) (Malay: Laluan Rel Pantai Timur) is a planned standard gauge double-track railway link infrastructure project. The construction began in August 2017 was suspended from July 2018 to April 2019. The project was continue with revised construction cost and southern alignment of the rail link.

ECRL will be connecting 6 different states starting from Selangor going to Wilayah Persekutuan Putrajaya, Negeri Sembilan, Pahang, Terengganu and stops at Kelantan. This project effectively connects the West Malaysia & East Malaysia with efficient time & cost management for customers.

There will be a total of 14 passengers only stations, 1 freight only station and 5 combined passengers & freight stations. MRL aims to ensure customers’ comfort towards the whole journey.

This project that costs RM44 billion cuts the travelling time of West-East Malaysia to 4-hour with total of 640km versus average of 7-hour drive for 474km. Now we can avoid long ride during festive seasons and opt for cheaper options than flying on plane or helicopter.

Any railway project will not be completed without interchange stations – and ECRL will not missed the opportunity for increase accessibility for their potential users. Currently, the project aims to have 3 interchange stations with Keretapi Tanah Melayu Berhad (KTMB), Express Rail Link (ERL) presently connects KL Sentral and KLIA and Mass Rapid Transit (MRT) that connects Sg. Buloh to/from Kajang.

There will be 2 service provided by ECRL namely Passenger Train that can speeds up to 160km/h and Freight Train that speeds up to 80km/h. This development too will include with double tracking for simultaneous ride to and fro at any point of the track.

The development of the ECRL will encourage economic growth along the corridor, many business opportunities will rise with this project. Upon announcement of this project, there are 1,321 submissions from Construction Industry Development Board (CIDB), break down to – 859 submissions or 65% are of G7 category of CIDB-rated companies, 134 submissions from Grade G5, 132 submissions from Grade G4 and 104 submissions and 92 submissions from Grade G3 and Grade G6 respectively. The project also encourages bumiputera participation that consists of 994 bumiputera engineering and construction companies representing 75.25% of the overall registration.

Related Articles You May Be Interested