SYNOPSIS

Post-tensioning works have been an important structural element for bridges and viaducts. To ensure the performance of the structure, engineers need to make sure the material and workmanship of the prestressing components are properly done at construction site. In the first part of the talk, the primary function of each component as well as the industry requirements on the materials for the post tensioning works will be explained. This includes the pc strands, post tensioning anchorage system, sheath/ducts, grouts, and the requirements for tensioning and grouting apparatus. Besides that, the relevant material testing and their acceptance criteria will be discussed. In the second part, the talk will explain the construction of the post tensioning works at site and the QA/QC requirements on the workmanship. This will cover the tendon installation, inspection before concreting and tensioning works, supervision during concreting as well as the grouting works. During this talk, the engineering fundamental of using tendon longation as part of the QA/QC work in the prestressed beam design will be explained. Along with this, participants will be shown how to analyse the tendon stressing records as well as the possible remedial work proposal for excessive positive or negative tendon elongations. On top of that, type of common site issues during tendon stressing and grouting works, and their possible contingency plans on how to handle these unlikely events will be discussed in the talk.


BIODATA OF SPEAKER

Ir. Dr. Low Hin Foo

Ir. Dr Low Hin Foo graduated from University Malaya with an Honours degree in Civil Engineering in 1999.

He obtained his Doctor of Philosophy in Engineering from Monash University in 2020 with his research on the experimental and numerical studies of a prestressed transfer plate subjected to staged casting and sequential stressing based on the actual prestressed transfer plate project in Kuala Lumpur. He has more than 22 years of design and construction experience in of prestressed building structures as well as various types of long-span bridges both locally and abroad. He was the Technical Manager for international prestressing specialist contractor, BBR Construction Systems (M) Sdn Bhd; and he is currently the Principal Engineer of a multidisciplinary consultancy firm, OSD Consultants (M) Sdn Bhd, as well as the Managing Director of OS Alliance (Singapore) Pte Ltd, and the Group Managing Director of OSD Alliance Design Group. Ir. Dr Low has vast design experience in the detailed design, construction and costing of prestressed structures for large commercial projects and high-rise towers, particularly in handling the design of prestressed flat slab or flat plate systems with irregular column grids, including prestressed transfer plates and raft foundation. Besides that, he has plenty of experience in the design and construction of integral bridges using precast girders made continuous, as well as long span bridges using precast and cast in-situ prestressed segmental box girders (SBG) and cable stayed bridges. Throughout the years, Ir. Dr. Low has contributed to the development of our nation by participating in numerous major infrastructure projects, including the detailed design of MRT stations and long-span crossings for KVMRT line 1 and line 2, elevated bridge viaducts in DASH and SUKE highways, as well as serving as the Independent Checker Engineer (ICE) for the structural design of the entire levated guideways and viaducts of LRT3 and RTS.

With his academic and practical industry experience, Dr Low is appointed as a committee member of the academic panel for Master of Structural Engineering and Construction Program of Universiti Putra Malaysia (UPM), Standing Committee Member of REAM Education Fund Committee, subcommittee of Engineers Australia Malaysian Chapter, and technical committee of the Structure Division of the Institute of Engineers Singapore (IES). He has also actively involved in seminars and training courses for engineers and undergraduates conducted by IEM, IES, JKR and various local universities and abroad on the design of bridges and prestressed building structures.