Sustainable high-strength concrete: enhancing performance with sugarcane leaf and sugar beet ash

Abstract

Abstract The amount of agricultural waste has grown as agricultural output has expanded globally. Therefore, in order to protect the environment, agricultural waste needs to be disposed of appropriately. Many studies used various types of agricultural wastes in concrete production as a partial replacement of cement to reduce carbon footprint. In order to produce sustainable high-strength concrete (SHSC), this study focusses on employing two promising pozzolanic materials: rice sugarcane leaf ash (SLA) and sugar beetroot ash (SBA) in SHSC production with different replacement levels up to 20%. This research provides a wide-ranging assessment of the mechanical, physical, durability and microstructural characteristics of SHSC. With a focus on advancing eco-friendly construction, the study also includes fly ash (FA) to assess its combined effects on SHSC’s mechanical and durability characteristics. SHSC mixtures were exposed to various tests to evaluate the influence of replacement from different aspects: slump test, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity, chloride penetration resistance, sorptivity, water permeability and scanning Electron Microscopy (SEM). According to the findings, replacing cement with SLA and FA up to 20% presented the optimum tests results, which led to significant enhancements in all physical, mechanical and durability properties of SHSC. Additionally, the inclusion of SBA with replacement level of 10% resulted significant enhancements to all SHCS characteristics whereas, compressive strength increased by 16%, tensile splitting strength increased by 10.8%, flexural strength increased by 12.4% and modulus of elasticity increased by 7.66% compared to the control specimens. With 20% FA replacement level, the optimum durability levels ware obtained; the lowest chloride permeability by 1342 Coulomb, the lowest sorptivity coefficient by 0.051 mm/√s and the lowest water permeability by 2.61 × 10 –11 cm/sec. In addtion, these improvements extended to FA replacement level of 10% mixtures’, including mechanical properties and also obtained lower durability terms results. Generally, cement replacement in all mixtures caused decrease in slump values comparing to control mixture. The SBA replacement level of 20% is technically useless, did not led to the expected improvement in all tested properties, and affected negatively SHSC mixtures. SEM images of new SHSC mixtures revealed that adding agricultural waste improved the SHSC’s microstructure by decreasing pore size, forming a denser SHSC structure and increasing the production of C–S–H. This study confirms the potential of SLA, SBA and FA as valuable supplementary cementitious materials, offering a sustainable alternative for producing durable SHSC with significant minimizing environmental impact.

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