METHOD AND APPARATUS FOR VACUUM FORMING OF CONCRETE LINER

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for vacuum forming of a concrete liner by which air bubbles can be made less on the outer peripheral face and inside and man-hour for finishing work can be remarkably decreased. SOLUTION: A form for vacuum forming in which a vacuum deaeration device is mounted on the midway of a concrete feeding path of a closed form for the liner and aperture area ratio of the unloading hole to the concrete feeding hole of the form is 0.3-0.7 is used and while deaeration is performed so as to make degree of vacuum in the form 6.6-46.1 kPa, a highly fluid concrete with a slump flow value of 55-85 cm is fed in the form.