Abstract
In recent years, the constructions of concrete structures in the underground have been increasing in towns and cities. For these structures, it is required to develop such concrete that will gain sufficient strength within early stage to shorten the construction period with economically reasonable cost for construction.
Experimental tests were conducted to develop a new concrete which will obtain strength more than 60kgf/cm2 within 4 hours after placing and will be applied for the lining concrete of the shield construction method. The results of experiments were satisfactory and are reported in this paper. The acceleration of hardening was attained by means of a new type of admixture, regulation of curing temperature and pressure application to the form.
