A Case Study of the Construction of Steel Structures in Cambodia: The Impact of Climate on Construction Operations
This paper examines the impact of weather conditions, including heat, rain and typhoons, on construction operations involving steel structures in Cambodia. The study is based on first-hand experience of the author, who worked in Phnom Penh, Sihanoukville and Battambang in Cambodia for a period of several years. In retrospect, the initial weather forecast was somewhat inaccurate. A client informed me that his previous steel shed had succumbed to rust within a year, and that the purlins had become distorted. Upon observation, it became evident that the steel in question was not inherently substandard; rather, its coating and design were not well-suited to the specific environmental conditions.
Cambodia experiences a rainy season that lasts for approximately six months of the year, with humidity levels frequently exceeding 80%. In addition to this, the country is subject to the occurrence of typhoons along its coastal regions. The act of reproducing designs from inland China has been demonstrated to be an ineffective strategy.
The primary function of the substance is to protect against corrosion. It is evident that the application of paint alone will not suffice.
A client operating within the garment manufacturing sector in Phnom Penh procured steel from an alternative supplier. Subsequent to a period of two years, the column bases had become so rusted that it was possible to scrape off chunks with one’s finger. In their stead, hot-dip galvanized sections with a minimum thickness of 85 μm were utilised. Subsequently, photographs were provided, which depicted the object in pristine condition.
It is my recommendation that: It is inadvisable to attempt to reduce expenditure on the process of galvanisation in Cambodia. The cost of this method is approximately 15% higher than that of field painting, but its durability is twice as great. In the context of coastal projects, such as those undertaken in Sihanoukville, the utilisation of sections with a thickness ranging from 100 to 110 μm, in conjunction with the application of an epoxy sealer coat, has been found to be effective.
Secondly, the matter of typhoon resistance is to be considered. It is evident that the installation of flat roofs alone is insufficient.
In the coastal regions of Cambodia, wind speeds can attain levels of up to 150 kilometres per hour. It has been determined that the design of many suppliers falls short of the required standard, with a deficiency of 0.4–0.5 kN/m² being observed.
The design of a warehouse in Sihanoukville was undertaken, with a span measuring 30 metres and a eave height of 9 metres. The design of the structure was undertaken with the intention of withstanding a load of 0.8 kN/m². This objective was achieved by incorporating wind columns and ensuring that the purlins were spaced 1.2 metres apart. In the preceding year, a major storm occurred. The shed belonging to the neighbour was destroyed, resulting in the loss of its roof. In contrast, our own experiment did not encounter any loss of panels.
The following key points are proposed: The wind columns were spaced at intervals of no more than 6 metres, the Z-section purlins were connected by lap joints, and anti-lift clips were employed for the roof panels.
Heat Insulation: It is inadvisable to attempt to create an environment comparable to an oven within the confines of a factory building without first installing appropriate roof insulation. In the absence of such insulation, the temperature within the building can reach 45°C when the external temperature is 35°C. The consequences of this are twofold: firstly, workers suffer from overheated machines, and secondly, machines overheat.
The utilisation of high-reflectivity white or silver panels, exhibiting a minimum reflectivity of ≥80%, in conjunction with 50 mm of fiberglass wool, has been found to be effective. The financial implications of this adjustment are negligible; however, a decline in indoor temperature of 5-8°C is to be expected. Following the implementation of the new system, the client operating the garment factory in Phnom Penh succeeded in reducing fan usage by 50%.
The delivery process is characterised by its expediency. The commitment to a duration of thirty days is not merely a rhetorical device, but rather an earnest assurance.
Cambodian clients have been shown to have a strong aversion to waiting. It is imperative that foreign factories initiate production without further delay, as each day of delay incurs financial losses.
The approach adopted is to utilise a standardised design, maintain stock inventory, and arrange direct shipment in a full container.
For instance: In the preceding year, a client operating within the Battambang region required a structure with a floor area of 2,000 square metres, intended for the purpose of housing swine. The process commences with the approval of the drawing and concludes with the arrival of the steel at the Sihanoukville port. The duration of the experiment was 25 days. The local crew were able to successfully install the main frame within a period of seven days. The client stated that this was almost a month faster than expected.
How? The company maintains a stock of standard sizes of H-beams, C-purlins and colour sheets. Subsequent to order confirmation, production is scheduled to take 15-20 days. Sea freight is required to reach Sihanoukville, with an additional 2-3 days allocated for customs processing.
Used steel structures: Cambodians have been observed to demonstrate an impressive degree of commitment in this regard.
Cambodian clients have been observed to demonstrate a heightened sensitivity to price. The market for used steel is considerable. It is company policy to maintain a supply of reclaimed Q355B sections that have undergone shot-blasting and re-coating processes. These items are of a quality equivalent to that of new items, yet they are available at a cost that is 50-70% lower.
One client operating within the e-commerce warehouse sector was constrained by a limited budget. The equipment provided to the subject included used main frames and new colour sheets. Total savings: 40%. Following a two-year period of use, the items are still in pristine condition.
Customs Clearance: Whilst not as stringent as the EAC, it is imperative that the documentation is accurate.
Despite the absence of an EAC requirement in Cambodia, the submission of material certificates, test reports, a packing list, a commercial invoice, and a bill of lading remains obligatory. In a particular instance, a client who had previously employed his own forwarder encountered a delay of three days in the clearance process. This delay was attributed to a discrepancy between the product name listed on the material certificate and that specified in the customs declaration. The fees incurred for demurrage escalated significantly.
It is my recommendation that: It is recommended that either an experienced forwarder is utilised, or that the entire process is conducted by the present company. A significant number of orders have been successfully dispatched to destinations including Sihanoukville, Phnom Penh, and Battambang, with the process now operating in an efficient and consistent manner.
The feasibility of constructing during the rainy season is a matter of interest.
The rainy season in Cambodia typically extends from May to October, with precipitation occurring on a near-daily basis. Prolonging the wait for the completion of the process will result in the loss of half a year.
The crew’s function is to erect temporary shelters. The processes of welding and painting are undertaken in a covered environment. The cessation of work is not necessitated by light rain; however, heavy rain necessitates the relocation of workers to indoor areas. Provided that the foundation does not flood, the process of steel erection can continue.
Key: The presence of drainage ditches on the premises is also a prerequisite. It is imperative to refrain from storing steel in direct contact with the ground; timber sleepers should be utilised for this purpose.
In conclusion, the author has worked on over a dozen projects in Cambodia, including garment factories in Phnom Penh, warehouses in Sihanoukville, and livestock barns in Battambang. In the event that one is planning a steel structure in this location and has inquiries pertaining to corrosion resistance, wind design, or cost control, one may pose these questions to the undersigned. My advice is free.