TAN B，Li J M，ZHANG L，et al．Preparation and study of self-compacting concrete with large amount of mineral admixture［J］. Journal of Henan Polytechnic University( Natural Science)， doi: 10.16186/j.cnki.1673-9787.2024100003.

doi: 10.16186/j.cnki.1673-9787.2024100003

Received： 2024-10-08

Revised： 2024-11-14

Online： 2026-07-22

Preparation and study of self-compacting concrete with large amount of mineral admixture (Online)

Tan Bo1,2,Li Jiemin1,2,Zhang Lei3, Li Guanfu1,2，Ming Yang1,2

1. School of Civil Engineering, Guilin University of Technology Guilin 541004, Guangxi, China;2. Guangxi Key Laboratory of Green Building Materials and Construction Industrialization, Guilin University of Technology, Guilin 541004, Guangxi, China;3. China Communications Road and Bridge South Engineering Co., Ltd., Beijing 101100, China

Abstract: Objectives In order to prepare self-compacting concrete with large dosage of mineral admixture and to explore the influence of the dosage of fly ash, mineral powder and ultrafine limestone powder on its performance. Methods An experimental study was carried out on self-compacting concrete with large admixture of fly ash compounded with mineral powder and large admixture of fly ash compounded with ultrafine limestone powder, focusing on its workability, durability, compressive strength and microscopic properties. Results The experimental results showed that the slump extension of self-compacting concrete with 30% fly ash (replacement of cement mass) compounded with 15% mineral powder and 30% fly ash compounded with 15% ultrafine limestone powder increased by 14.6% and 12.3%, and the slump increased by 23.0% and 18.6% respectively compared with that of pure cement; from the age of 7 d to 28 d, the growth rate of compressive strength of 30% fly ash mixed with 15% mineral powder and 30% fly ash mixed with 5% ultrafine limestone powder increased by 27.5% and 16.7% respectively, compared with that of pure cement; At the age of 28 d, the carbonation depth of self-compacting concrete with 30% fly ash mixed with mineral powder and 30% fly ash mixed with ultrafine limestone powder increased compared with pure cement, At the age of 84 d, the chloride migration coefficient of self-compacting concrete with 30% fly ash compounded with 15% mineral powder and 30% fly ash compounded with 5% ultrafine limestone powder were reduced by 35.6% and 28.9%, respectively, compared with pure cement; microstructural observation shows that the large dosage of mineral admixtures had different degrees of secondary hydration reactions with cement hydration products. Conclusions The working performance of self-compacting concrete with 30% fly ash compounded with mineral powder and ultrafine limestone powder was significantly improved compared with that of pure cement; the compressive strength of self-compacting concrete with 30% fly ash compounded with mineral powder and 30% fly ash compounded with an appropriate amount of ultrafine limestone powder was similar to that of pure cement at the age of 28 d. at all ages, the carbonation resistance of self-compacted concrete with 30% fly ash compounded with mineral powder and appropriate amount of ultrafine limestone powder is lower than that of pure cement,while chlorine ion penetration resistance of self-compacting concrete with 30% fly ash mixed with mineral powder and appropriate amount of ultrafine limestone powder is improved compared with pure cement.; the secondary hydration of self-compacted concrete with 30% fly ash compounded with 20% of mineral powder is obvious, which fills up the microcracks and holes inside its structure.

Key words: self-compacting concrete; workability; durability; compressive strength; micromorphology; mineral admixtures