Abstract
In this study, to reduce carbon dioxide caused global warming, it attempts to manufacture high volume mineral admixture (HVMA) concrete using large content of by-products blast furnace slag and fly ash, and 10 % of cement occurred carbon dioxide. As compressive strength of HVMA concrete is lower, the concrete experiment was performed using inorganic additives, an inorganic additives of CSA, anhydrous gypsum and calcium oxide, for strength increase of normal concrete degree. At the slump of concrete, CSA 1 % series was not showed loss of change after 1 hour, but CSA 2 % series showed significant loss of change after a hour. And air content of concrete was not change between initial and 1 hour later, so additives was not affect air content. Compressive strength of 28 days was measured 23.4~30.7 MPa at CSA 1 % and range of 25.4~39.1 MPa at CSA 2 %, it increased according to usage of CSA and anhydrous gypsum, but it did not show significant changes about use of calcium oxide. Elastic modulus of 28 days was measured 27.4~29.5 GPa at CSA 1 % and range of 27.2~32.0 GPa at CSA 2 %, and its range of change according to additives were lower compared to compressive strength. Considering fluidity and mechanical properties of concrete, it is judged that optimum combination ratio of additives for performance revelation of HVMA concrete at normal concrete area was CSA is 1 %, and anhydrous gypsum and calcium oxide is 2~4 % respectively. Therefore, HVMA concrete made by only 10 % of cement and a little inorganic additives is expected that reduce carbon dioxide at concrete in manufacturing field and match government policy of low carbon green growth.
