Gunungkidul - No material in this world can not be utilized. Each material can be used in accordance with its specification. Starting from this notion, the Department of Civil and Environmental Engineering Faculty of Engineering Universitas Gadjah Mada (UGM), particularly the Laboratory of Building Materials has done various researches on basic building materials (non-sand concrete) in the last few years.
According to Head of the Laboratory, Ir. Kardiyono Tjokrodimuljo, M.E., non-sand concrete is a simple form of lightweight concrete that uses no sand in its making.
"Because without the sand, the concrete becomes lightweight," Kardiyono said in the opening of Workshop on the Application of Research Results, Non-Sand Concrete Technology, in the Meeting Room of Regional Planning and Implentation Board of Gunungkidul Regency on Thursday (29/7).
The workshop followed by about 60 participants was collaboration between the Civil and Environmental Engineering Department UGM with Center for Skills Guidance and Construction Engineering Ministry of Public Works and the Gunungkidul Regional Planning and Implentation Board.
Further, he added that non-sand concrete manufacture is relatively simple, using gravel, cement and water. As it does not contain sand, its characteristic is lighter in with little cavity. Non-sand concrete material is suitable for absorbing wells, road pavement, handicrafts (concrete tube, fertilizer tanks, bataton etc).
"Cement is less needed because this concrete does not contain sand," he explained.
Non-sand concrete developed over the past 20 years has been disseminated in several areas such as Purwobinangun (Sleman), Purwoharjo (Kulon Progo), Pleret (Bantul), and Planjan (Gunungkidul). The development has been done by some SMEs as well as through service-learning students. "I don’t remember how much it costs, but this is already applied by some SMEs as well as our service learning students," he said.
According to Kardiyono, at least it can suppress the production rates by about 20% of the price of ordinary concrete using sand mixture. "Non-sand concrete can supress production costs up to 20% of the ordinary concrete with sand. Now, we're looking for the Indonesian National Standard Certificate," Kardiyono explained.
Prior to development, non-sand concrete has also undergone laboratory research and field tests. He cited the manufacture of bricks from the non-sand concrete (Batagama) in Jambon, Bawuran, Pleret, Bantul, non-sand reinforced concrete structures for gate buildings in Kemiri Village and Condongcatur housing, concrete tube for absorbing wells, road pavement and handicrafts.
Meanwhile, Deputy Dean for Student Affairs, Research and Cooperation of Faculty of Engineering, Prof.Ir. Jamasri, Ph.D, said that non-sand concrete is one of the results of research from Faculty of Engineering that has been applied. Some other results that have been implemented include biogas from Department of Chemical Engineering, the village of biogas in Kulon Progo, and micro-hydro power plant in cooperation with State Electricity Company (PLN).
"Hopefully, this research can be more useful after being applied in the community," Jamasri explained.
On the other hand, Vice Regent of Gunungkidul, Hj. Badingah, S. Sos, opening the workshop explained that the results of research and application of non-sand concrete technology is appreciated. It needs to be followed up remembering its various prospective values for developing the region and community, particularly in the karst region of Gunungkidul.
"The karst area of this region with its different types of rocks as building materials makes this technology as one solution in the development of local resource-based technology," she explained.
The availability of raw materials in Gunungkidul makes it possible to develop non-sand concrete technology as an alternative for mining operations with substantial added value, including the production of brick, concrete tube, printed concrete, etc.