(Japan) — A serious shortage of ready-mixed concrete in areas hit by the Great East Japan Earthquake has been causing delays in reconstruction work.
While high demand for ready-mixed concrete for constructing dikes, rebuilding houses and other construction projects has contributed to the shortage, the problem has been exacerbated by difficulties in storing and transporting the material. Because concrete becomes hard in a short period of time, it is difficult to make in advance, store or produce in distant locations.
As concrete production cannot keep up with demand, some disaster-hit areas have experienced delays in reconstruction work. Some have voiced concerns that if no solutions are put forward, reconstruction may come to a complete halt.
Earlier this month at the Taro fishing port in Miyako, Iwate Prefecture, about 10 kilometers north of the city’s center, a 47-year-old construction company employee overseeing reconstruction work there said, “When will the concrete be delivered?”
While ready-mixed concrete is necessary for bank protection work and building tetrapods, which protect coastlines, they could not procure the material despite making many requests. In late June, the company received 30 cubic meters of ready-mixed concrete–less than half the quantity it had ordered–a week behind schedule.
“I’m sure we won’t be able to finish construction by the scheduled completion date at the end of October. I can’t even picture when work might be completed,” the employee said.
The delay in rebuilding the port has caused trouble for local fishermen. “Because of land subsidence triggered by last year’s disaster, the port is easily inundated by spring tides, among other things. Under these circumstances, we can’t leave the port to fish. How long will we have to wait [until reconstruction is finished]?” a 70-year-old local fisherman said angrily.
New plants hard to build
A cooperative association of ready-mixed concrete wholesale dealers in the Miyako area estimates that demand for the material in Miyako and Yamada, also in Iwate Prefecture, will be about 400,000 cubic meters this fiscal year, seven times more than usual.
However, the three plants in the area are only capable of producing about 150,000 cubic meters. Even if a floating concrete mixing-plant were built to produce the material at sea, it would only produce an extra 120,000 cubic meters. According to the prefecture’s Ready-Mixed Concrete Industrial Association, it is difficult to build new plants because large plots of land are already being used for disaster debris disposal.
Ready-mixed concrete is made by mixing water, gravel and cement. If the material is already drying when it is cast into a mold, its strength could be reduced. For that reason, the Japan Industrial Standards stipulate that ready-mixed concrete should be delivered to construction sites within 90 minutes of being produced.
As a result, while iron frames and other construction materials can be manufactured in advance and stored until needed, it is impossible to do so for ready-mixed concrete. This poses a problem for producing concrete in the prefecture’s inland areas, which suffered less damage, as it takes about two hours to transport the material to heavily damaged coastal areas.
In Miyagi Prefecture, demand for ready-mixed concrete for next fiscal year is estimated at about 4.7 million cubic meters, while actual supplies are expected to reach only 4.2 million cubic meters.
To address the situation, the Miyagi prefectural government and private organizations have jointly established a liaison council. The council conducted a survey to identify when and which areas are likely to face concrete shortages and is now considering asking neighboring regions to help supply those areas.
In the prefecture, most reconstruction work is still in the initial stages and full-scale construction is slated to begin in autumn. A situation that is expected to further exacerbate concrete shortages.
In Sendai, the city’s Tozai subway line is scheduled to begin operations in fiscal 2015. Construction work on the subway line is expected to intensify soon, and will likely spur a concrete shortage.
According to a cooperative association of ready-mixed concrete producers in Sendai, gravel is also scarce. As gravel is an essential ingredient in making ready-mixed concrete, that limits how much production can be increased. “While it’s common sense that we should speed up reconstruction efforts, it’s problematic that central, prefectural and municipal governments are simultaneously ordering construction projects. It’s necessary to prioritize where and how to use a limited amount of materials,” an association official said.