IREFER to the letter “Cracks, leaks: Review archaic building codes” (NST, Oct 14) by Ariff Shah R.K.
As a professional engineer, I have to highlight some issues in relation to Ariff’s questions.
Concrete structures remain the main type of building structure in Malaysia due to their relatively low construction costs, durability and the availability of high-quality raw materials.
Concrete has weaknesses and is susceptible to degradation, especially when quality assurance measures are not monitored during the construction stage.
We have well-trained consultants in the construction industry, which is regulated by numerous codes in the design and construction of concrete structures. The Street, Drainage and Building Act 1974 (Act 133) and Uniform Building By-Laws 1984 are the key building codes in Malaysia.
Cracks are inevitable due to the presence of water in concrete mixture. Some cracks are not dangerous, but they present an opportunity for water to seep in if not sealed in time. Different types of cracks give us signs about the structure and are warnings for us to take action before any catastrophic failure occurs.
Cracks can be minimised if durability factors are integrated into its design. Unfortunately, durability is not given due concern in the design stage in many projects because it is not mandatory. The durability of structures can be significantly improved by using higher grade concrete.
During the construction stage, quality control of concrete in both fresh (taking slump test) and hardened (conducting cube compression test) states must be conducted strictly.
Good industry practices of taking care of concrete include keeping moisture inside the concrete to ensure the cement hydration process is sufficient.
In the search for profit, many good industry practices are often neglected.
Short construction periods of 24 months (landed) or 36 months (high-rise) worsen the situation.
Some resident engineers even “help” vendors using premixed concrete to pass the slump test.
This “kind” gesture to vendors is ironically detrimental to ensuring the quality of the concrete structures.
Quality control at the construction stage is important to realise the envisioned lifespan of the buildings.
A well-trained engineer who knows the materials and the mechanisms of dealing with concrete can ensure improvement in concrete quality.
During its service lifespan, water and environmental contaminants play a major role in the degradation of concrete.
The Malaysian Meteorological Department anticipates that greenhouse gases will cause more heatwaves in the future.
The adverse implications of this include stronger drifting caused by stronger wind and more cracks on the facades of high-rises.
Section 85A of Act 133 stipulates mandatory structural integrity inspection of buildings that are five levels or higher once a decade.
The Housing and Local Government Ministry, on the other hand, recommends the BS EN 1504 British standard in the event rehabilitation of concrete structures is needed.
Our tropical climate and the adverse effects of greenhouse gases must be considered to ensure reasonable durability of design and when doing repairs.
Criteria like chemical resistance, flexural fatigue resistance (elasticity) and stability under ultraviolet rays and heat are important in the selection of materials for optimum lifecycle costs.
Building managers need to be familiar with BS EN 1504 to be able to maintain buildings well.
They must also monitor slope, drain and retaining walls against soil erosion in anticipation of the effects of greenhouse gases.
To recap, we need to train engineers to adopt more advancements in concrete construction technology.
I believe that with the great potential of young engineers and talented students, the availability of advanced materials in the Malaysian market, the kindness of nature to Malaysia and the abundance of high-quality raw materials, it is possible to produce high-quality concrete structures with a lifespan of more than 100 years without a need for major repair.
PAYAM SHAFIGH
Department of Building Surveying, Universiti Malaya