In recent years, the deterioration of concrete structures is a significant social problem in Jap'an. To solve this
problem, researchers and engineers are conducting the researcn and technical development for solution of the
problem. They proposed various techniques and materials in the past, but they fail to find out any reliable and
effective methods at present. The effective microorganisms, which were invented by one of the authors, showed
remarkable performance in the agricultural and enVIronmental fields. The authors selected four kinds of materials
from these, and started to study the feasibility of their application to admixture for concrete, and to help solve the
deterioration problem. As a result, the study revealed the p'ossibility of soMng the deterioration problem. We report
some data that suggest that the considerably effective admixture can be produced. Some results obtained from
indoor experiments are as follows. (1) This new admixture has the fairly powerful surface activity, the effect of air
entraining (AE) agent, i.e., gassing reaction, and the effect of water reducing agent, i.e., the function to disperse the
agglomerated particles. (2)lhe compressive strenath at day 3 and day 7 of curing was compared. The strength of
thiS admixture was found to be larger by 30 to 50%' than that of contro. It means lhat initial strength increaseCl. (3)
We conducted the acceleration test with carbon gas concentration of 5%, humidity of 6Q01o and temperature of
20'C. The result showed almost complete suppression of carbonation. This is a very promising result for solution
of concrete deterioration problem.