Concrete composition using blast furnace slag composition

Abstract

Disclosed is a concrete composition which is capable of securing good construction workability by suppressing decrease in fluidity of the concrete composition or decrease of air in the concrete composition over time, while suppressing the discharge amount of carbon dioxide. The concrete composition is also capable of suppressing drying shrinkage of a hardened product thereof and providing the hardened product with a necessary strength. Specifically disclosed is a concrete composition containing at least a cementitious material, water, a fine aggregate, a coarse aggregate and an admixture, wherein the blast furnace slag composition described below is used as the cementitious material at a mass ratio of water / blast furnace slag composition of 30-60%. Blast furnace slag composition: a blast furnace slag composition which is obtained by adding 0.5-1.5 parts by mass or 5-45 parts by mass of an alkali activator per 100 parts by mass of a mixture that contains 80-95% by mass of a ground granulated blast furnace slag powder having a fineness of 3,000-13,000 cm2 / g and 5-20% by mass of gypsum (with the total of the blast furnace slag powder and the gypsum being 100% by mass).

Description

technical field [0001] The present invention relates to a concrete composition obtained using a blast furnace slag composition. In recent years, there has been an increasing demand for reduction of carbon dioxide emissions and improvement of energy consumption efficiency. In view of the foregoing, in the field of concrete compositions, granulated blast furnace slag (blast furnace castor slag) by-produced from ironworks is effectively used as a raw material of blast furnace slag cement in the form of blast furnace slag fine powder. Blast furnace slag cement, which is usually used in concrete compositions, is manufactured by mixing blast furnace slag fine powder with ordinary Portland cement. According to JIS-R5211, it is classified into type A (more than 5% to 30%), Type B (over 30% to 60%), and Type C (over 60% to 70%). The above-mentioned blast furnace slag cement has the following advantages: low heat of hydration, large increase in long-term strength (strength), high wate...

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Problems solved by technology

However, in these conventional proposals, if the amount of blast furnace slag fine powder used is actually increased, 1) good workability cannot be ensured, 2) it is difficult to suppress the drying shrinkage of the hardened body, and 3) the decrease in the compressive strength of the hardened body increases. and other issues that in some respects pose significant obstacles

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