Effect of sand-to-aggregate volume ratio on durability of concrete

• Published in: Innovative infrastructure solutions : the official journal of the Soil-Structure Interaction Group in Egypt (SSIGE) 2022-10, Vol.7 (5), Article 318
• Main Authors: Mohammed, Tarek Uddin, Bin Harun, Mohammad Zunaied, Joy, Jamil Ahmed
• Format: Article
• Language: English
• Subjects: Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Foundations; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Technical Paper
• ISSN: 2364-4176; 2364-4184
• DOI: 10.1007/s41062-022-00915-8

The durability of concrete is mostly dependent on the quantities and properties of its ingredients. As the major part of concrete is occupied by fine and coarse aggregates, a comprehensive investigation was conducted to assess the effect of the sand-to-aggregate (s/a) ratio on the durability of concrete, such as resistance toward carbonation and chloride ingress. For investigation, concrete samples were made with different s/a (0.36, 0.40, 0.44, 0.48, 0.52, and 0.56), cement content (340 kg/m 3 and 450 kg/m 3 ), water-to-cement ratio (0.45 and 0.50), and maximum aggregate size (MAS) (12 mm and 19 mm). Rapid chloride permeability test (RCPT) was done at the age of 28 days of concrete. For the carbonation test, the samples were exposed to an accelerated carbonation chamber (3% carbon dioxide, 70% relative humidity, 40 °C temperature). By spraying phenolphthalein solution on the freshly broken concrete surface, carbonation depth was measured periodically. Concrete specimens were also tested for mechanical properties and ultrasonic pulse velocity (UPV). This extensive investigation elucidates that the optimum s/a ratios for the least depth of carbonation were 0.40 and 0.44 for the MAS of 12 mm and 19 mm, respectively. On the other hand, the chloride ingress in concrete is increased with the increase in s/a irrespective of cement content, W/C, and MAS.