Since the proposal of the concept of zero emission in 1994, many efforts have been made to attain it in various fields of industries. The industries related to concrete materials have done like the other industries, receiving waste or by-product from them. This report introduces the characteristics of concrete materials and the present condition of each materials for zero emission.

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Cement demand in Japan has been still under recession hence economic crisis in 1990. All cement producers are depressed their production and suffered severe financial problem by low operation availability and low market price, however at the field of environment, cement kilns are expected as core part of waste-recycle-system in society. Cement kilns are operated by high temperature (1 400-1 500°C) and can utilize industrial waste or by-products as secondary fuel without dioxin and all residue are composed with clinker. Furthermore, by installing the additional process such as by-pass system of chlorine, the reusable wastes could be increased and extended to another elements containing materials. Each cement plant is also struggling with cost reduction and energy saving by introducing new production technology, and rationalizing the plant operation by applying latest computer technology of automatic and labor-saving system. In addition to above, new type of cement such as “high strength and high fluidity concrete” are developed by research and development in order to catch up the diverse market needs.

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In 1989 the Hokuriku expressway's Daikeiji River Bridge was given cathodic protection as a countermeasure for salt-induced corrosion. This was the first such case in Japan. In the nine years that have passed since cathodic protection was applied, corrosion of the steel reinforcements in the concrete has not progressed in spite of an environment with an amount of chloride much greater than 1.2 kg/m³, the amount above which corrosion is presumed to be initiated. In addition, it is thought that effective conditions for corrosion protection have been maintained for nine years because the specified depolarization has been maintained at 100 mV. As for the evaluation of the performance of anode materials, titanium anodes, which were used in the impressed current cathodic protection system, were found to have no corrosion at all. Therefore it is presumed that the bridge's life span, initially estimated to be 40 years, will be attained. As for zinc sacrificial nodes in the galvanic cathodic protection system, they last approximately 7 years, although the consumption rate of the anodes differs depending on the steel density inside of the concrete and on the corrosive environment.

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