JKR FORENSIC SHOW CASE PROJECT 1; REPAIR TO DETERIORATED STRUCTURAL MEMBERS, DATARAN LANG, KUAH, LANGKAWI, KEDAH DARUL AMAN

ACKNOWLEDGEMENT – PAPER CONTRIBUTOR

Ir. Dr. Lim Char Ching, Director of Engineering of Road Branch has been with JKR Malaysia for more than 30 years and is The Subject Matter Expert for Forensic Works.

Ir. Dr. Lim was involved in numerous investigations and structural remedial works. He has published and presented more than 35 technical papers in International and National Journals and Conferences and written more than 380 reports on structural investigation and assessment and conducted more than 150 lectures in related fields.

PROBLEM STATEMENT

Located in Kuah Town and next to the jetty, Dataran Lang (Eagle Square) is one of Langkawi’s best known man-made attractions. The square is marked by a massive 12-meter sculpture of an eagle; ‘Lang‘ from where the name Langkawi originates. It mainly covers a landscaped area of fountains, footbridges, covered pavilion and shops (Astaka).

In 2014, Lembaga Pembangunan Langkawi (LADA) intends to carry out remedial works to Dataran Lang. JKR was engaged to inspect and carry out structural assessment works. Observation made on the existing building and ancillary structures had indicated that immediate remedial works need be carried out to extend the service life and enhance the overall structural integrity, already compromised by corrosion and damages to the structural components.

INVESTIGATION WORKS

ZONE A AND B – MAIN SCULPTURE PLATFORM

The inspection was carried out by visually checking on each of the structural components; which include the deck slabs, beams and the pile caps. Nearly all the structures have some forms of damage. The damage and defects can be summarised as below:

• Cracks in RC beam & RC slab;
• Delamination & spalling of RC beam, RC slab and RC pile cap;
• Rebar corrosion due to carbonation and chloride attack;
• Reduction of rebar cross sectional area.

Severe delamination and spalling of concrete underside of beam

Extensively spalled concrete at soffit of deck slab as a result of corroded steel reinforcements

Severely delaminated and spalled concrete pile cap with the steel reinforcements exposed. 

ASTAKA

The visual inspection on each of the structural components can be summarised as below:

• Cracks in RC beam and RC arch roof,
• Water leaks and failure in waterproofing.

Efflorescence and stalactites observed on the surface of arch concrete roof suggesting the presence of cracks and water leaks

Multiple cracks observed at the underside of the arch roof. These cracks will further promote the deterioration process of RC material, resulting in spalling of concrete

WORK UNDERTAKEN ON SITE

ZONE A AND B – MAIN SCULPTURE PLATFORM

The structure though suffered from common damage or defect in marine environment, the remedial works must be carried out to extend the service life of the existing structure. The proposed method of structural recovery included:

• Structural crack sealing
• Hand patch repair – spalled concrete
• Formwork pressure grouting – substantial spalled concrete
• Replacement of corroded steel reinforcements
• Protective coating to all exposed concrete

Hacking and removal of decay or damaged concrete

Rust removal of rebar and apply anti-corrosion coating on existing / new rebar

Air-tight formwork installation along the structural component

Injection of shrinkage compensated cementitious grout into the formwork

ASTAKA

The scope of structural repair included:

• Structural crack sealing
• Installation of new waterproofing system

Surface crack sealing on top of concrete arch roof

Spray-applied waterproofing  membrane on top of concrete arch roof

COMPLETED WORKS

Zon A & B: Newly repaired / protected RC beam and RC slab

Application of protective coating to all exposed concrete surface at the splash zone

Astaka: Repaired cracks and painting works at soffit of arch roof

Astaka: The completion of waterproofing and structural repair works

END NOTE

Photos of completed the works are worth thousands of words. The repair works were successfully done to the client’s satisfaction and the structural integrity of the Dataran Lang was successfully upgraded to withstand the severe marine environment and thus will continue to be a main tourists attraction for a long time to come in this Land of The Legend, Mahsuri.

JKR – Jasa Kepada Rakyat