BelangZ

Date of Construction: October - December 2010 A 10-year-old trapezoidal monsoon drain was found cracked and damaged. Damaged trapezoidal drain From visual observation, defect may be caused by: Differential soil settlement below and on the sides of the trapezoidal drain. This causes drain structure to move unevenly. Results in crack of drain. Through these cracks, water seepages occur. The flow loosens and erodes the soil that supports the drain. Settlement increases with time. Recommendation: To reconstruct the monsoon drain using precast U-drain . Advantages: 1. Precast – quality of work can be controlled. 2. Shorter duration of work completion - faster speed of construction. 3. U-shape of drain requires less working space thus will not affect trenches and piping. 4. Drain also acts as retaining wall – provides soil stability from lateral movements. Disadvantages: 1. Higher cost by 3.6% as compared to in-situ re-construction of trapezoidal drain. 80% completion 100% Co...

Date: 13 January 2011 Anchor Bolt - A fastener used to fastened an element to a base material. To perform maintenance on existing structure can be very challenging as we do not have the freedom of space to work with. An anchor bolt for an equipment at my work place failed in tensile mode, causing increased in vibration reading of the equipment. To repair this, we have reached out to HILTI Malaysia, a specialist in anchoring. There are 2 types of anchors: Cast-In Anchor and Post-Installed Anchor Cast-In anchor is widely used on new construction, which is not an option for my repair work. It is not economically feasible to demolish most part of the concrete in order to cast in the anchor. Also, the time is a constraint. Thus, post-installed anchor is the best option. However, some calculations are required to ensure strength of anchor with overall loading. Cast-In Anchor Types of Cast-In Anchor: 1) Headed Bolt 2) L-Bolt 3) J-Bolt 4) Stud-welded plate. Advantage...

Date: 6 December 2010 Location: Malaysian Mega Galvaniser Sdn Bhd, Klang, Selangor Went for a factory visit with my site supervisors to witness hot-dip galvanising process for our Monsoon Drain Re-Construction Project . Introduction: Hot-dip galvanizing is the process of coating iron, steel, or aluminum with a thin layer of zinc. This process results in a metallurgical bond between zinc and steel with a series of distinct iron-zinc alloys.The zinc carbonate formed is fairly strong and protects the steel layer below from further corrosion. Steel will not rust due to the cathodic protection offered by zinc coating, that will be oxidized before steel. Source: Wikipedia Process: Source: MMG SB 1) Degreasing Surface of material must be properly cleaned before galvanising. The expected lives of hot-dip galvanised products are mainly affected by this process. The material is immersed in a degreaser tank containing detergent additives to remove any substance (oil, gre...