Press Release Back Number(2003)

Developing habitat-friendly concrete blocks for bank protection
-Environmentally-friendly blocks made from the coal ash generated by thermal power plants-

November 25, 2003

In the course of promoting the recycling of coal ash generated by thermal power plants, Chubu Electric Power has succeeded in applying coal ash to develop environmentally-friendly concrete blocks on which plants and organisms can grow. These blocks are typically used to protect the banks of waterways.

The newly-developed blocks are known as porous concrete blocks. Although consisting of concrete, the blocks contain pores through which plant roots, water, and air can permeate, encouraging the growth of plants and other organisms. Current environmental conditions call for innovative measure to preserve and restore the valuable waterfront environment found alongside rivers. Such blocks are expected to play an increasingly important role in river bank protection projects.

Conventional porous concrete blocks (hereinafter referred to as "conventional blocks") are produced by binding gravel with a substance consisting of cement and water in a way that traps and isolates any pockets of free space. In contrast, the newly-developed blocks consist of crushed pieces of solidified coal ash, not gravel, which is then bound with cement and water. This technology promotes effective use of coal ash.

We also improved the compounding ratio of materials and production methods to increase the porosity of blocks, resulting in blocks whose porosity ratio is 50% above conventional blocks. Since the new blocks are made of coal ash, which offers high water retention, they provide twice the water retention of conventional blocks.

Increases in porosity ratio and water retention help create a hospitable environment for the growth of plants and organisms. Additionally, the technology used to form blocks from solidified coal ash rather than gravel reduces gravel use and the environmental impact of gravel gathering. We will now seek to commercialize these innovative, environmentally-friendly blocks.

< Development highlights >

  • Using crushed pieces of solidified coal ash instead of gravel creates an application for recycled coal ash and reduces the environmental impact of gravel gathering.
  • Improvements in the compounding ratio of materials and production methods made it possible to establish a technology that enables production of blocks with porosity ratios 50% higher than conventional blocks. (The porosity ratio of newly-developed blocks is 18%, while that for conventional blocks is around 10% to 12%.)