This paper reviews various emerging alternative SCMs derived from minerals and biomass sources, industrial byproducts, and underutilized waste streams. The paper compiles and evaluates physicochemical properties, reaction mechanisms in cementitious systems, resource availability, supply chain dynamics, technology readiness, the impact on concrete performance, and environmental and cost factors for each candidate SCM. Specifically, the review examines wood ash from bioenergy plants, volcanic and sedimentary natural pozzolans, and construction and demolition waste. This includes recycled concrete fines, asphalt plants’ rock dust (baghouse fines), aggregate production fines, and post-consumer waste, particularly municipal solid waste incinerator ash and wastewater sludge ash. Additionally, the paper explores innovative additives such as cellulose and chitin nanomaterials and calcium–silicate–hydrate nanoseeds to address challenges of slower strength development and rheological changes. The key contribution of this review is a multifactor framework for assessing alternative SCMs, emphasizing availability, supply chain, market readiness, and environmental performance, combined with an engineering performance review.

A rapid, simple, and sensitive differential kinetic method is presented for the determinations of acetaminophen (also known as paracetamol) and salicylamide. The method is based on their oxidation reaction by Fe³⁺ ion in the presence of 1,10-phenanthroline as indicator. The reactions can be monitored spectrophotometrically by measuring the increase in the absorbance of the solution at 510 nm. Two times were selected one in which only paracetamol is oxidized by Fe³⁺ ion and the other in which both drugs are oxidized by Fe³⁺ ion. The data were evaluated by the proportional equations method. The method allowed the simultaneous determination of paracetamol and salicylamide at concentrations between 0.5–20 and 1–40 μg/mL with relative standard deviations of 3.47 and 2.58%, respectively. The method was applied to the simultaneous determination of paracetamol and salicylamide in human serum and pharmaceutical formulations.

In 2016, global cement consumption reached 4.65 billion tonnes, accounting for 8% of the world’s carbon dioxide emissions. Reducing the reliance on cement is an effective strategy for mitigating cement’s climate impacts. This study investigates rice straw ash (RSA) as a supplementary cementitious material (SCM) for concrete. To enable large-scale RSA production via rice straw combustion at bioenergy plants, the effect of varying water-soaking durations (3, 6, 24, and 72 h) on the leaching of salts and heavy metals from rice straw was assessed. The resulting leachate was treated by reverse osmosis, producing clean water for irrigation and a potassium-rich fertilizer concentrate. The soaked rice straw was combusted to produce RSA samples (RSA 0 for unsoaked straw, and RSA 3, RSA 6, RSA 24, and RSA 72 for soaked durations) for evaluation as SCM based on physicochemical properties, pozzolanic reactivity and strength activity index (SAI), available alkalis, and alkali-silica reactivity (ASR) mitigation. Results revealed that a soaking duration of just 3 h was effective at removing harmful compounds detrimental to combustion systems. All RSA samples exhibited high pozzolanic reactivity (heat release > 335 J/g and calcium hydroxide consumption > 130 g/100 g RSA) and SAI exceeding 120%. Furthermore, soaking was effective in enhancing ASR mitigation, achieving an 85% expansion reduction with RSA 3. This study demonstrates the potential of rice straw as bioenergy feedstock and its ash as a viable SCM for concrete, offering a pathway to reducing cement consumption while creating value-added uses for agricultural residues.

This study demonstrates the successful use of eco-friendly recycled glass powders (RGPs) in mortar and concrete as pozzolanic substitute for portland cement. As part of the evaluation, two RGPs were produced by steel and ceramic ball mills, namely, RGP (SB) and RGP (CB), respectively. Also included in the experiment as a reference was a commercial ceramic ball-milled RGP. All three evaluated RGPs were found to be reactive pozzolans based on a series of reactivity test results, including a strength activity index of greater than 80 % on all ages of 7, 28, and 56 days in mortar and concrete. Multiple indicators, such as higher generated heat in pozzolanic reactivity testing by isothermal calorimetry and portlandite consumption, indicated ceramic milling could produce a more reactive glass pozzolan, perhaps from the alumina residue from ceramics milling media. However, the higher reactivity of RGP (CB) did not lead to a greater compressive strength when used in concrete. Furthermore, a color difference was not detected between RGP (SB) and RGP (CB) concrete specimens. This study shows that both steel and ceramic media are viable for RGP production based on pozzolanic reactivity, strength, electrical resistivity, and concrete color. Other factors, such as productivity and cost, should be considered when choosing the proper production method for RGP at the industrial scale.

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