Alex Liew has spent 20 years researching and developing a low-cost construction method using waste and has employed unskilled workers to cast the earthquake- and cyclone-proof houses. By building the sample unit for the construction company, he wants to spread awareness of the low-cost casting and fast construction methodology to more and more contractors so that India and other poorer countries can make durable Lightweight Fiber Reinforced houses for the poor and homeless.
During his recent visit to Imphal this year, Alex got the idea of building low-cost houses using bamboo as reinforcement. The components include starter bars for walls, joints and also mesh bamboo fibers in the lightweight concrete as Bamboo Fiber Reinforced Lightweight Concrete. According to him, use of bamboo strips as starter bars, can replace steel as bamboo lasts for thousands of years whereas steel bars are prone to rusting. Bamboo and its fibers when treated with chemicals ensure that water is not absorbed and does not affect the concrete during hydration.
Casting of a raft foundation takes only 4 hours and is immediately followed by installation of formwork. After door & window frames, water pipes and electrical conduits are put in place, the chosen concrete is pumped in, and the house is ready in 8 hours for de-molding, and the casting commences for the next unit.
For the raft foundation, Alex used a new method of Pad-footing and kickers trown. With this, there would not be any need for the thick cement raft concrete base in the center of the halls and rooms as these areas are only meant for walking (with only a bed or some furniture) and have no load-bearing. Walls are also made in the Raft Pad Floor Beams style, a new method that saves a few m3 of concrete. All the walls are made using reusable formwork cast at one time and the entire structure is completed in less than 15 hours. A unit costs around USD 3,500.00 without toilets and it is expected that the cost will go up to a maximum USD 7,000 per unit with good floor tiles, windows, doors and ceilings.
The developers, contractors and workers were impressed with the technique and are now planning to cast 500,000 units at the rate of 200 units/day or 6,000 units/month. Says Alex: "This is just the start; I am confident that with the spread of the technical know-how and awareness of the multiple benefits of this construction method, more and more construction companies will come forward to adopt this technology."
(Read an earlier article on the topic at https://www.nbmcw.com/product/peb-prefab/38477-lcm-low-cost-house-casting-technology.html)
