The effects of limestone powder and fly ash as an addition on fresh, elastic, inelastic and strength properties of self-compacting concrete


Hilmioglu H., Sengul C., Özkul M. H.

ADVANCES IN CONCRETE CONSTRUCTION, vol.14, no.2, pp.93-102, 2022 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 2
  • Publication Date: 2022
  • Doi Number: 10.12989/acc.2022.14.2.093
  • Journal Name: ADVANCES IN CONCRETE CONSTRUCTION
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Page Numbers: pp.93-102
  • Keywords: blocking, critical stress, fly ash, initiation stress, limestone powder, modulus, Poisson ratio, SCC, slump flow, strength, HIGH-PERFORMANCE CONCRETE, MECHANICAL-PROPERTIES, RHEOLOGICAL BEHAVIOR, HARDENED PROPERTIES, MINERAL ADMIXTURES, PORE STRUCTURE, FAILURE, CEMENT, PASTE, CONSTITUENTS
  • Istanbul Technical University Affiliated: Yes

Abstract

In this study, limestone powder (LS) and fly ash (FA) were used as powder materials in self-compacting concrete (SCC) in increasing quantities in addition to cement, so that the two powders commonly used in the production of SCC could be compared in the same study. Considering the reduction of the maximum aggregate size in SCC, 10 mm or 16 mm was selected as the coarse aggregate size. The properties of fresh concrete were determined by slump flow (including T-500 time), V-funnel and J-ring experiments. The experimental results showed that as the amount of both LS and FA increased, the slump flow also increased. The increase in powder material had a negative effect on V-funnel flow times, causing it to increase; however, the increase in FA concretes was smaller compared to LS ones. The increase in the powder content reduced the amount of blockage in the J-ring test for both aggregate sizes. As the hardened concrete properties, the compressive and splitting strengths as well as the modulus of elasticity were determined. Longitudinal and transverse deformations were measured by attaching a special frame to the cylindrical specimens and the values of Poisson's ratio, initiation and critical stresses were obtained. Despite having a similar W/C ratio, all SCC exhibited higher compressive strength than NVC. Compressive strength increased with increasing powder content for both LS and FA; however, the increase of the FA was higher than the LS due to the pozzolanic effect. SCC with a coarse aggregate size of 16 mm showed higher strength than 10 mm for both powders. Similarly, the modulus of elasticity increased with the amount of powder material. Inelastic properties, which are rarely found in the literature for SCC, were determined by measuring the initial and critical stresses. Crack formation in SCC begins under lower stresses (corresponding to lower initial than in normal concretes, while critical stresses indicate a more brittle behavior values.