Self-Compacting Concrete With High-Volume Crushed Rock Fines

Dry crushed rock fines (CRF) which is a nuisance waste at crushed rock aggregate plants has been investigated for its use as a mineral addition in concrete. According to the research conducted so far, both methylene-blue test and sand equivalent test can be applied for the screening test on the quality of CRF. Furthermore, CRF is useful not only as supplemental fines in fine particle lacking aggregates such as sea-dredged sand, but also for high-volume fines in self-compacting concrete. This paper presents the test results of a prototype reinforced concrete column and wall structure cast with self-compacting concrete (SCC) containing high-volume of CRF (CRFSCC). Judging from the test results of concrete cores obtained from the column and wall of the structure, the following conclusions were obtained: (1) The greater the distance the concrete flowed through reinforcing steel bars, the greater the segregation of the CRFSCC; (2) Both the front part of the CRFSCC flow and upper part of the CRFSCC structure contained less amount of coarse aggregate, and showed both low values for modulus of elasticity and high values for drying shrinkage; (3) In order to get more homogeneous quality in the structure with CRFSCC, special care is needed for concrete casting procedures - it is suggested that a reverse casting flow direction technique may be effective; and (4) Drying shrinkage of CRFSCC did not result in deleterious cracking on the structure.