Permeability study of water-proofing admixture and fly ash incorporated concrete using standard and own built test

Abstract

One of the most important factors influencing concrete's age is its permeability. Many commercially available water-proofing chemicals claim to be helpful in water-proofing concrete while improving other attributes such as compressive strength, modulus of rupture, durability, and density. Furthermore, the mineral admixtures also improve concrete's mechanical and durability properties. DIN 1048 (Part 5), EN 12390 – 8, and IS 516 (Part 2): 2018 are standard codes for determining the water permeability of concrete. These codes lack information on the drying conditions of concrete samples between the pressure cycles of water permeability tests and leads to an inability to evaluate the effectiveness of using admixtures in concrete. Some more limitations of these codes are fixed duration of testing and bulky apparatus. In this study, the one- and four-cycle test with oven drying and the air-drying combination is carried out. The present study also focuses on evaluating the effectiveness of fly ash and waterproofing admixture as an additive in concrete to reduce the water permeability of concrete. Further, limitations of the previous test are taken into consideration, and the own built apparatus is developed. The own-built apparatus (water penetration test) works at the same pressure (5 kg/cm2) as the standard method. The own-built apparatus reduces the testing duration, and a more significant number of samples can be tested at a time compared to the traditional method. The results of water penetration depth for the different samples prepared at a common effective w/c ratio have given an insightful effect, as the concrete with similar strength was compared for permeability evaluation. Therefore, the present paper will enlighten the testing procedure, duration, and comparison of (0, 15, 25, and 35%) fly ash and (0.8 and 1.2%) waterproofing admixture concrete. The 15%, 25% and 35% fly ash incorporated concrete was found effective by 18 to 27% in reducing the penetration depth, whereas 0.8 and 1.2% water proofing admixture concrete reported 9 and 14% effective compared to control concrete. This study will help researchers to evaluate the comparative effectiveness of the ability of water-proofing and mineral admixtures in improving the permeability of the concrete and ultimately enhancing the durability of the concrete structure.