Multi-Criteria Optimization of Cost-Effective and Environmentally Friendly Reactive Powder Concrete Incorporating Waste Glass and Micro Calcium Carbonate

Abstract

In pursuit of developing an eco-friendly and cost-effective reactive powder concrete (RPC), we utilized a multi-objective optimization technique. This approach pivoted on the incorporation of byproducts, with a spotlight on ground glass powder (GP) as a pivotal supplementary cementitious material (SCM). Our goal was twofold: engineering cost-efficient concrete while maintaining environmental integrity. The derived RPC showcased robust mechanical strength and impressive workability. Rigorous evaluations, containing attributes like compressive strength, resistance to chloride ion penetration, ultrasonic pulse speed, and drying shrinkage, highlighted its merits. Notably, the optimized RPC, despite an insignificant decrease in compressive strength at 90 days compared to its traditional counterpart, maintained steady strength augmentation over time. The refinement process culminated in a notable 29% reduction in ordinary Portland cement (OPC) usage and a significant 64% decrease in silica fume (SF), with the optimized mix composition being 590 for cement, 100 for SF, 335 for GP, and 257 kg/m3 for calcium carbonate. Additionally, the optimized RPC stood out due to the enhanced rheological behavior, influenced by the lubricative properties of calcium carbonate and the water conservation features of the glass powder. The reactive properties of SF, combined with GP, brought distinct performance variations, most evident at 28 days. Yet, both mixtures exhibited superior resistance to chloride, deeming them ideal for rigorous settings like coastal regions. Significantly, the RPC iteration, enriched with selective mineral admixtures, displayed a reduced tendency for drying-induced shrinkage, mitigating potential crack emergence.

A Comprehensive Overview of Recycled Glass as Mineral Admixture for Circular UHPC Solutions

“…In recent years, there has been a concerted scholarly effort focused on harnessing the potential of GP as a substitute for conventional UHPC-making materials [1,47,[55][56][57][58][59].…”

“…As can be observed, the reported XRD analysis of recycled glass particles reveal their amorphous nature, characterized by a minor presence of long-range atomic order. This amorphous phase, typical of soda-lime glass materials [47,49,50,59,78], is a key factor in their pozzolanic activity when used as glass powder in concrete [79,80]. The absence of crystalline structure allows for greater reactivity with calcium hydroxide during cement hydration, resulting in the creation of secondary C-S-H gel.…”

“…Therefore, confirming the amorphous nature of recycled glass particles through XRD analysis is essential for evaluating their suitability as supplementary cementitious materials and predicting their effectiveness in enhancing concrete properties [50]. For its part, Table 4 presents some physical properties of recycled glass particles utilized in UHPC mixtures [24,42,59,64,75]. For its part, Table 4 presents some physical properties of recycled glass particles utilized in UHPC mixtures [24,42,59,64,75].…”

“…For its part, Table 4 presents some physical properties of recycled glass particles utilized in UHPC mixtures [24,42,59,64,75]. For its part, Table 4 presents some physical properties of recycled glass particles utilized in UHPC mixtures [24,42,59,64,75]. Moreover, Figure 3 puts forward the SEM (Scanning Electron Microscopy) analysis of the particles of recycled waste glass utilized in several UHPC formulations [29,47,82,83].…”

“…A multi-criteria optimization technique was carried out to design two eco-friendly UHPCs incorporating micro-limestone powder and two different sizes of GP as cement and SF partial replacements [47,59,75]. The UHPC formulations analyzed, which included a Control dosage without alternative binders, as well as their scheme of pastes' packing density, are presented in Table 6 and Figure 6, respectively.…”