Effect of Supplementary Cementitious Materials on Corrosion Resistance of Reinforced Concrete Ayad A. Mousa, Jasim M. Abed, Mohammed H. Shukur Civil and Environmental Engineering, 2025 Reinforced concrete (RC) durability particularly in chloride and sulphate-rich environments is seriously compromised by corrosion. This study explores how Supplementary Cementitious Materials (SCMs) fly ash, silica fume, ground granulated blast furnace slag, and metakaolin collectively improve corrosion resistance and durability. A rigorous experimental regime, including compressive strength testing, water absorption, sorptivity, rapid chloride penetration tests, sulphate attack resistance, half-cell potential measurements, chloride diffusion assessments, and linear polarization resistance tests, was implemented. Multi-SCM mixtures significantly outperformed individual SCMs, exhibiting a 68% drop in chloride permeability, 64% less sulphate-induced expansion, and an 81% reduction in steel corrosion relative to conventional concrete. Notably, mix M13 achieved exceptional microstructural refinement and a compressive strength of 70.7 MPa 38% higher than the control alongside superior resistance to aggressive ions. However, this enhanced SCM content led to noticeable workability issues, reducing slump values by approximately 38%. Although the introduction of superplasticizers partially mitigated these drawbacks, practical implementation at a larger scale remains challenging. Further, uncertainties persist regarding long-term real-world performance, necessitating additional field validations. Ultimately, while SCM blends clearly offer substantial durability advantages, future investigations should prioritize optimizing mix proportions, addressing workability concerns, and verifying laboratory results in actual exposure conditions. This will support the advancement of sustainable, resilient RC infrastructures with enhanced corrosion resistance.
Impact of using recycled fine aggregate from demolition waste on mechanical properties of cement mortar Jasim Mohammed Abed, Hiba A. Abdul Kareem Al-Uzbaky, Muthanna Abbu Archives of Civil Engineering, 2025 The rapid expansion of the construction industry worldwide has led to a significant increase in resource use, hence depleting the existing reserves. Utilizing recycled aggregates might potentially reduce the use of natural raw materials in the production of concrete and mortar. This would further aid in reducing the quantity of waste thrown into the environment due to demolition procedures. This study investigated the feasibility of recycling recycled fine aggregate from construction and demolition waste. Limestone powder was utilized as a filler, together with waste from three different kinds of construction and demolition waste (concrete, clay bricks, and ceramics). Cement mortar mixtures of 1:3:0.5 and 1:4:0.5 were used to design 32 different mortar mixes (cement: fine aggregate: filler). Except for the control mixes, the following replacement ratios were tested: 0%, 20%, 40%, 60%, 80%, and 100% for construction and demolition waste as a partial replacement for natural fine aggregate. Cubes, prisms, and cylinders were all used to measure the physical and mechanical properties of the mortar. In this study, the physical properties (workability, dry density) were analyzed. In addition to investigating the mechanical properties (compressive, flexural, and splitting strength), The experimental results showed that the optimal percentage of natural fine aggregate replacing recycled aggregate from construction and demolition waste was 20%. Additionally, the research demonstrated that, due to its cementitious properties, recycled fine aggregate from concrete waste significantly outperformed the reference mixes in terms of all physical and mechanical properties.
Effect of Partial Replacement of Fly Ash and Expanded Polystyrene waste on Properties of Geopolymer Concrete Bricks Journal of Advanced Research in Applied Sciences and Engineering Technology, 2019
