Porosity evaluation of concrete containing supplementary cementitious materials for durability assessment through volume of permeable voids and water immersion conditions

Abstract

Concrete containing supplementary cementitious materials (SCMs) as partial replacement of ordinary Portland cement is regarded as green and durable concrete, with several advantages such as improved strength gain mechanism, resistance to degradation and extended service life of structure. Water absorption or porosity of concrete is directly related to the durability of concrete. In this present study, five concrete mixes involving three different SCMs are investigated for water absorption and rapid chloride penetration rating. A comparison between porosity values obtained using four standard testing methods, i.e., BS 1881-122, RILEM CPC 11.1, RILEM CPC 11.3, and ASTM C642 are presented for three different concrete mixes containing varied compositions and proportions of two SCMs. The testing method by RILEM CPC 11.3 includes distinctive sample preparation and is regarded as a stringent method to represent the degree of concrete porosity. Two additional concrete mixes with three SCMs are further investigated for their water absorption and immersion following the testing method by RILEM CPC 11.3. The impact of SCMs on concrete porosity is discussed. A linear correlation between porosity and rapid chloride penetration (RCP) ratings obtained as per ASTM C1202-19 on specimens of all investigated concrete mixes is proposed as a rapid approach to assess chloride penetration of concrete specimens containing SCMs.