INVESTIGATION ON PROPERTIES OF READY MIXED CONCRETE OVER TRANSIT TIME
DOI:
https://doi.org/10.11113/mjce.v35.20289Keywords:
RMC; transit time; setting time; workability; compressive strength.Abstract
Ready-mixed concrete (RMC) is a contemporary item that facilitate to mix concrete in a specialized yard and deliver it at site while ensuring the quality as fresh concrete. The transit time of RMC, which is influenced by road congestion, is important since it may have an impact on the workability and compressive strength of RMC. Therefore, it is necessary to investigate the impact of transit time on properties of RMC. In this study, a two-phased experimental program was designed; where RMC has been used with (phase-1) and without admixture (phase-2). Concrete mix-ratio was designed to attain M20 concrete; however, the target strength was 25MPa. Fresh concrete properties, i.e., workability, was measured at designated times (i.e., 0, 45, 90, 120, 150, 180 and 210minutes) over a period of 3.5 hours after the mixing of concrete. Over this period, concrete-mixer was continuously rotated at 18-20 rpm speed and cylinders were cast at previously mentioned time intervals. The experimental results showed that transit time has a remarkable impact on workability of RMC when the admixture is not utilized, i.e., slump value reduced from 210 to 25mm over 3.5 hrs. travelling. However, the slump value can be maintained up to 115mm using 1% admixture. In contrast, there is no remarkable impact of transit time on the compressive strength as the average strength in both phases reached or relatively close to the target strength (i.e., 25MPa). The target strength compliance might be attributed to the continuous rotation of the RMC mixer during the transit time
References
Al-Martini, S., & Nehdi, M. 2010. Effects of heat and mixing time on self-compacting concrete. Proceedings of the Institution of Civil Engineers-Construction Materials, 163(3): 175-182.
ASTM C19, 2021. “Standard Test Methods for Time of Setting of Hydraulic Cement by Vicat Needle”. ASTM International. https://www.astm.org/c0191-21.html.
ASTM C33, 2018 “Standard Specification for Concrete Aggregates”. ASTM International”. https://www.astm.org/c0033_c0033m-18.html.
ASTM C143/C143M, 2020. “Standard Test Method for Slump of Hydraulic-Cement Concrete”. ASTM International. https://www.astm.org/c0143_c0143m-20.html.
ASTM C39/C39M, 2014. “Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens”. ASTM International https://www.astm.org/c0039_c0039m-14.html.
ASTM C39/C39M, 2021. “Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens”. ASTM International https://www.astm.org/c0039_c0039m-21.html.
ASTM C494/C494M, 2022. “Standard Specification for Chemical Admixtures for Concrete”. ASTM International. https://www.astm.org/c0494_c0494m-19e01.html.
Chowdhury., M. I. Kayes & SK. S. Ali. 2016." Effect of Delay in Casting on Compressive Strength of Concrete". Proceedings of 3rd International Conference on Advances in Civil Engineering, 21-23 December 2016, CUET, Chittagong, Bangladesh.
Cordoba, G. P., Zito, S. V., Sposito, R., Rahhal, V. F., Tironi, A., Thienel, C., & Irassar, E. F. 2020. Concretes with calcined clay and calcined shale: Workability, mechanical, and transport properties. Journal of Materials in Civil Engineering, 32(8): 04020224.
Daniel, D. G., & Lobo, C. L. (2005). User's Guide to ASTM Specification C 94 on Ready-mixed Concrete. ASTM International.
Erdoǧdu, Ş. 2005. Effect of retempering with superplasticizer admixtures on slump loss and compressive strength of concrete subjected to prolonged mixing. Cement and Concrete Research, 35(5): 907–912.
Gaynor, R. D., Meininger, R. C., & Khan, T. S. 1985. Effect of temperature and delivery time on concrete proportions. In Temperature Effects on Concrete. ASTM International.
Kırca, Ö., Turanlı, L., & Erdoğan, T. Y. 2002. Effects of Retempering on Consistency and Compressive Strength of Concrete Subjected to Prolonged Mixing. Cement and Concrete Research, 32(3): 441-445.
Loh, L. T., Yew, M. K., Yew, M. C., Beh, J. H., Lee, F. W., Lim, S. K., & Kwong, K. Z. 2021. Mechanical and thermal properties of synthetic polypropylene fiber–reinforced renewable oil palm shell lightweight concrete. Materials, 14(9): 2337.
Mahzuz, H.M.A., Bhuiyan, M.M.H. & Oshin, N.J. 2020 Influence of delayed casting on compressive strength of concrete: an experimental study. SN Applied Sciences 2: 316.
Manjunatha, L. R., Anvekar, S. R., Sagari, S. S., & Kumarswamy, A. 2014. A Study On Customer Preferences and Perceptions On Quality and Services of Ready Mixed Concrete as a Sustainable Building Material in Bangalore City, Karnataka. International Journal of Research in Engineering and Technology, 3: 2319-1163.
Mohan, D., & John, E. 2020. Study on slump retention of ready-mix concrete: A Review. International Research Journal of Engineering and Technology, 7(7): 1784-89.
Rahman, M. M. 2011. Study on ready-mix concrete with experiments and survey in context of Bangladesh, Under graduation Thesis, Ahsanullah University of Science and Technology.
Shahidan, S., Abdul Rahim, M., NikZol, N. S., Azizan, M. A., & Ismail, I. 2015. Properties of Steel Fiber Reinforcement Concrete with Different Characteristic of Steel Fiber. In Applied Mechanics and Materials 773: 28-32. Trans Tech Publications Ltd.
Shaikuthali, S. A., Mannan, M. A., Dawood, E. T., Teo, D. C. L., Ahmadi, R., & Ismail, I. 2019. Workability and compressive strength properties of normal weight concrete using high dosage of fly ash as cement replacement. Journal of Building Pathology and Rehabilitation, 4(1): 1-7.
Trejo, D., & Chen, J. 2014. Effects of extended discharge time and revolution counts for ready-mixed concrete (No. WA-RD 831.1). Washington (State). Dept. of Transportation. Research Office.
Zhao, W., Yang, J., Zhao, W., & Yang, C. 2021. Experimental study on the influence of mixing time on concrete performance under different mixing modes. Science and Engineering of Composite Materials, 28(1): 638-651
