How sea sand is fortifying Sri Lanka’s construction sector
By Uwin Lugoda
The global construction industry has always been at the forefront of technological advancement, with its emphasis on scale, safety, durability, and deadlines. Sri Lanka’s construction and development projects too have striven – particularly during this decade – to keep abreast of global developments and cutting-edge technologies in its rapid post-war infrastructure and skyscraper development drive.
This growth in the construction sector has led to an increased demand for building materials and chief among them is sand. Much of the sea sand used in construction comes from rivers due to its accessibility. However, the heightened demand soon became a threat to the environment, with an increase in the depth of river beds, lowering of the water table and salinity intrusion into the rivers being observed.
This compelled the Government to impose restrictions on river sand, which in turn created a scarcity that consequently pushed up its prices. In fact, during the last six years, the price of river sand has doubled, making it almost unaffordable to the majority of the general public.
To address these issues of environmental preservation, scarcity, and high prices, the Sri Lanka Land Reclamation and Development Corporation (SLLRDC) has come up with an alternative to river sand; sea sand.
SLLRDC Chairman Roshan Gunawardena spoke to The Sunday Morning Business about an initiative that is nearing completion to replace commonly used river sand with much more abundantly available sea sand in the construction industry. Gunawardena stated that the department looks to provide a more efficient and cheaper alternative not only to the Government, but to the public as well.
The SLLRDC was originally established with one motive: To have available land for the development drive in Sri Lanka. This motive has grown not only to reclaim land, but to help the government and the public develop their own lands as well. This also includes maintaining flood-free habitats and improving the environment by rehabilitating, creating, and maintaining pollutant-free inland water bodies.
Sea sand was first used as an alternative to river sand back in 1994, when dredged sea sand was used in the reclamation of a 400-arce land in Kerawalapitiya, Muthurajawela. Since then, dredged sea sand has been used in the construction of highways and in other government projects.
“When we experienced the scarcity of raw materials in the construction industry, the Government wanted us to introduce sea sand to the industry because sand is a vital raw material,” Gunawardena said.
He added that the department focused its attention on making sea sand a widely available product. During the project’s initial stages, natural rain water had been used to wash the salt off the sand. But this method wasn’t successful because of the unpredictability of rain and very little acceptance from the public. This is when they introduced mechanical washing and sieving.
Since 2017, the department has been using this method to prepare sea sand for construction use and since then, sea sand has become immensely popular, with the demand rising by 30% annually. During this phase, Gunawardena stated that they went into the private sector to take up the challenge of washing and sieving sea sand, but due to low capacity, the SLLRDC called upon one of its subsidiaries, Redeco. Within 13 months, Redeco accomplished the task of importing and installing machines, in turn allowing the plants to start issuing washed and sieved sea sand at a very high capacity – double that of the private sector companies starting from 1 April 2019.
Gunawardena explained that they currently have four outlets in Kelaniya (Mudun Ela), Kirimandala Mawatha (Nawala), Attidiya (Dehiwala), and their main storage in Kerawalapitiya. But starting May, they are looking to open outlets in five more locations to keep up with the growing demand. These new outlets will come up in Divulapitiya, Hanwella, Panadura, Ratmalana, and Kesbewa.
He also went on to explain that the department was looking to introduce a smart pack from 1 July 2019 to make it more convenient for the people.
“In the sales point, we only do bulk sales right now, but when we take Colombo, as it is very suburban, big trucks sometimes can’t reach certain areas through narrow roads. As a solution, we decided to come up with a handy pack – it’s like a 50 kg cement bag.”
Currently, a cube of river sand costs about Rs. 16,000-19,000. But when it comes to washed and sieved sea sand, it only costs Rs. 8,700 at their main outlet in Kerawalapitiya. Sand from their other outlets would cost around Rs. 9,000-10,000 depending on the transport cost. This makes sea sand 40-50% cheaper than river sand.
Speaking of the process, Gunawardena explained that sand is dredged 10 km from the shore and is pumped inland. It is then washed, sieved, and dried before being sent to the factory for packaging. The plants that currently function have the capacity to make about 2,000 bags per hour. He stated that depending on the demand, the capacity will be increased. Sand will be drenched in shores off Bopitiya, Uswetakeiyawa, and in-between Negombo and Colombo.
Gunawardena stated that they are currently engaged in negotiations with an American company which introduces technology that can test sand for salt content within seconds. This will allow them to test sand at a moment’s notice in front of customers to prove its viability.
“People had the fear that sea sand is not suitable for construction, but now I can guarantee that if the sea sand is properly washed and adhered to proper standards, there is no harm at all. All the highways and the elevated roads were built using our sea sand. Our sand has also been used for several high-rise buildings that are more than 10-15 stories.”
Further, SLLRDC is having discussions with the Sri Lanka Standard Institute to obtain the Sri Lanka Standard Certificate. This means that each pack would come with the Sri Lanka standard certification, adding an extra layer of assurance for the customer.
Gunawardena said that they have already invested billions in this project and that introducing sea sand to the market was a good business for the SLLRDC, and the department expects returns to come in from the project in 2020 or 2021.