混和材としての瀬戸粘土(木節.蛙目)の利用について

Abstract

The materials so-called Kaolin clays which were distributed in Seto district, Aichi prefecture, were used as an admixture for Portland cement concrete. Those kaolin clays are "Kibushi" and "Gairome" clays utilized as raw materials for porcelain, and common clay which is deposited in the same district, but this has not been used for the ceramic industry. The each clays were ground into fine powder with the specific surfaces by Elaine's method of 7000 to 9000 sq cm per g, and were calcined at the temperatures of 400℃, 700℃ and 1000℃ to induce satisfactory properties as pozzolanic materials. The experiments were carried out on mortar with 10 to 30 percent replacement of cement by raw or calcined clay fines, and mortars without clay were also made for comparison purpose. As results of the Flow test and Compressive strength test at age of 7, 28 and 91 days, a contribution to the strength was observed in the mortar which 10 percent of cement were replaced by calcined clays at 700℃ or 1000℃. The strength ratio increased with age, in the calcination at the temperature 1000℃. It is considered that the increase is caused by the pozzolanic reaction.