EVALUATION OF THE PROPERTIES OF AIR ENTRAINED CONCRETE AT MODERATE WATER-CEMENT RATIO
Abstract
This work investigated the use of air entraining agents in concrete as a way of proposing a suitable dosage required for structural concrete. A special type of air entraining agent (costamix c) was used in the study. Laboratory tests were carried out on the concrete samples; slump test and compressive strength tests. The slump tests were to measure the workability of concrete carried out using slump cones, base plates, tamping rod, sample scoops, slump cone filling and a measuring device in accordance with the standard procedure while, the compressive strength tests involved mixing of the constituents; cement, sand, coarse aggregates, air entraining agent and water at at moderate water-cement ratio of 0.6 and casting of the concrete cubes on moulds of 150 x 150 x 150 mm. The cubes were demoulded after 24 hours and cured in water after which testing for the strength using the concrete compression machine was done after 7, 21 and 28 days respectively. The result of the slump test was 30mm for specimen without air entraining agents as against 70mm for those with 1.0% air entraining agent indicating increase in workability with the presence of air entraining agent. While the compressive strength for all levels of addition of air-entrainers, there was increase in the 7-days compressive strength but reduction in the 28 days strength but the most advantageous compressive strength with air entrainer was obtained at 0.9% for the various days; the 28-day compressive strength being 21.44 N/mm2 at that level of addition.
KEYWORDS: water-cement ratio, workability, air entrained, concrete, compressive strength
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Ashraf, W., Glinicki, M.A., & Olek, J. (2018). Statistical analysis and probabilistic design approach for freeze–thaw performance of ordinary portland cement concrete. journal of materials in civil engineering.vol 30,pp. 04018294. https://doi.org/10.1061/(asce)mt.1943- 5533.0002494
Backus, B. (2024).Concrete slump testing. journal of construction materials and testing,Vol 12 No 1, pp. 119-129
Freeman, J.M. (2012). Stability and quality of air void systems in concretes with superplasticizers. master’s thesis, oklahoma state university, stillwater, ok, usa.
Guo, S., Dai, Q., Sun, X., Sun, Y., &Lliu, z. (2017). Ultrasonic techniques for air void size distribution and property evaluation in both early-age and hardened concrete samples. applied sciences, 7, pp. 290.
Hover, K.C. (2001). Entrained air in concrete. aci manual of concrete practice, vol. 1.
Jakobsen, U.H., Pade, C.,Thaulow, N., Brown, D, Sahu, S., Magnusson, O., Buck, S., & Schutter, G. (2006). Automated air void analysis of hardened concrete—a round robin study. cement and concrete research.Vol 36 No 3 pp. 1444-1452.
Khedr, S., Abou-Zeid, M., &Abadir, J. (2012). Response of air-entrained concrete to severe chemical aggression. journal of the american society of civil engineers.Vol 110,No 9 pp. 1233-1245.
Laustsen, S. Hasholt, M.T., & Jensen, O.M. (2008). A new technology for air-entrainment of concrete. rilem publications, pp. 1223-1230.
Powers, T.C. (1964). Topics in concrete technology: 3. mixtures containing intentionally entrained air. journal of the pca research and development laboratories.Vol 6,No 3 pp. 19-41.
Song, Y., Shen, C, Damiani,R.M., & Lange, D.A. (2021). Image-based restoration of the concrete void system using a 2d-to-3d unfolding technique. construction and building materials Vol. 270, pp. 121-476.
Suárez, F., Conchillo, J.J., Gálvez, J.C., & Casati, M.J. (2018). Macro photography as an alternative to the stereoscopic microscope in the standard test method for microscopical characterisation of the air-void system in hardened concrete: equipment and methodology. materials.Vol. 11, pp. 15-19.
Tao, J., Gong, H., Wang, F., Iuo, X., Qiu, X., & Huang, Y. (2021). Automated image segmentation of air voids in hardened concrete surface using photometric stereo method. international journal of pavement engineering.Vol. 24, pp. 1-18.
Wang, R., Hu, Z., Y., Wang, K., & Zhang, H. (2022).Review on the deterioration and approaches to enhance the durability of concrete in the freeze–thaw environment. construction and building materials, Vol 321, pp. 126371.
Zhang, P., Li, D., Qiao, Y., Zhang, S., Sun, C., & Zhao, T. (2018). Effect of air entrainment on the mechanical properties, chloride migration, and microstructure of ordinary concrete and fly ash concrete. journal of materials in civil engineering, Vol 30, pp. 4018265. https://doi.org/10.1061/(asce)mt.1943- 5533.0002456
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