Normal Concrete Mix Design based on the Isoresponse of Slump as a Function of Specific Surface Area of Aggregate and Cement Paste-Aggregate Ratio

Abstract

Many methods of normal concrete mix design produce the same proportion of cement and water content of concrete for different specific surface area of aggregate. Therefore, they often produce inappropriate workability of fresh concrete in the first batch. In the end, several trial batch adjustments are required by increasing or decreasing cement paste for reaching the required slump. This research aims to find out the correlation between specific surface area of aggregate and cement paste-aggregate ratio (C/A) to slump in a constant water-cement ratio (W/C) in normal concrete. This correlation will be used as an alternative method of normal concrete mix design. First, the new fine aggregate was established by modifying natural fine aggregate gradation. Then, two reference mixtures with these natural and modified fine aggregates were designed based on SNI 03-2834-2000. From each of these mixtures, the water content was added and reduced at multiple of 10 kg/m 3 in a constant water-cement ratio until the measured slumps of samples had approached or reached 6 and 18 cm. Thus, different specific surface area of aggregate, cement paste-aggregate ratio, and slump could be known. Then, an isoresponse is developed to present the correlation between these variables. Finally, other mixtures are designed based on this isoresponse to validate it. The isoresponse is considered satisfactory if the measured slump of the validation mixtures does not deviate more than 2 cm of the required slump. The result shows that the measured slumps of validation mixtures had maximum deviations of 1 cm only. It means that the isoresponse of slump as a function of specific surface area of aggregate and cement paste-aggregate ratio can be used to predict the slump of a mixture and also as an alternative method of normal concrete mix design.

Digital Image Correlation for the Determination of Mechanical Properties of Concrete with Modified Expanded Polystyrene

“…The manufacturing process and mix design of polystyrene concrete have been investigated to optimize its properties and performance (Zhang, 2021). Researchers have investigated different additives, mix proportions, and curing methods to improve the strength, durability, and workability of the material (Shabbar, Al-Tameemi, and Alhassani, 2022;Ulhaq and Andayani, 2021;Mwero and Onchaga, 2020;Patidar et al, 2019;Xu et al, 2012).…”