Worldwide cement production is around 4.2 billion tons, and the fabrication of one ton of ordinary Portland cement emits around 900 kg of CO₂. Blast furnace slag (BFS) is a byproduct used to produce alkali-activated materials (AAM). BFS production was estimated at about 350 million tons in 2018, and the BFS reuse rate in construction materials of developing countries is low. AAM can reduce CO₂ emissions in relation to Portland cement materials: Its use in construction would be a golden opportunity for developing countries in forthcoming decades. The present research aims to formulate AAM destined for future applications in developing countries. Two activators were used: NaOH, Na₂CO₃, and a mixture of both. The results showed that compressive strengths within the 42–56 MPa range after 28 curing days were obtained for the Na₂CO₃-activated mortars. The characterization analysis confirmed the presence of hydrotalcite, carbonated phases, CSH and CASH. The economic study showed that Na₂CO₃ was the cheapest activator in terms of the relative cost per ton and MPa of manufactured mortars. Finally, the environmental benefits of mortars based on this reagent were evidenced, and, in terms of kgCO₂ emissions per ton and MPa, the mortars with Na₂CO₃ yielded 50% lower values than with NaOH.

Used tires (UTs) are a global problem, especially in developing countries due to inadequate management systems. During retreading, when the worn tread is replaced, waste is generated in the form of tire fibers (TFs) and particles, which can be reused as raw materials to produce economically and environmentally low-cost prefabricated elements. Using TFs as a lightweight aggregate in nonstructural geopolymer-based elements is a sustainable valorization option. This study aims to valorize used tires by incorporating them as TFs into lightweight geopolymer mixes and analyzing their physico-mechanical, thermal, and thermography properties for building and civil engineering applications. The geopolymer is produced from a precursor (spent catalyst residue from catalytic cracking, FCC) and an alkaline activator composed of rice husk ash (RHA), sodium hydroxide, and water. The control sample’s (mortar with siliceous sand, CTRLSIL) compressive strength came close to 50 MPa, while the TF mixes ranged from 32 to 3 MPa, which meet the masonry standards. The thermal conductivity and thermography analyses showed that increasing the TF content reduced the heat transmission and achieved a similar performance to expanded-clay concrete and better performance than for conventional concrete.

In high-altitude regions of the Global South, social housing programs are essential for mitigating vulnerability to low temperatures, but their standardized designs often fail to meet thermal performance codes. This study evaluates a “Sumaq Wasi” adobe housing module in the Peruvian Andes (Kunturkanki, 4237 m a.s.l.) during the 2023 frost season. We comparatively applied the 2014 and 2022 draft versions of the Peruvian standard EM.110 to assess the building envelope’s thermal transmittance and condensation risk, benchmarking monitored indoor temperatures against adaptive comfort models. The results revealed widespread non-compliance with thermal transmittance limits, especially for the roof and floor, although condensation risk was low. While indoor temperatures failed to meet conventional standards, they aligned with regionally adapted comfort ranges. We conclude that the standardized module design is insufficient for local climatic demands and argue that social housing policies must evolve, balancing regulatory stringency with context-aware bioclimatic design to be effective.

The artisanal production of paints using inorganic pigments from the Cusco Valley is considered a sustainable alternative to the use of synthetic industrial paints. This approach not only helps reduce the environmental footprint associated with the use of volatile organic compounds (VOCs) but also utilizes local materials. The present study evaluates the physical and mechanical properties of paints obtained from natural pigments through standardized tests based on the American ASTM standards, focusing on adhesion (ASTM D-3359), drying time (ASTM D-1640), surface hardness (ASTM D-3363), and the performance of the paints when exposed to the environmental factors of Cusco (under real conditions). In this regard, the pigments were extracted from traditional quarries and processed through the sedimentation method (MS) and ball milling (MG). The produced paints were formulated with the addition of polyvinyl acetate (PVA) as a binder and water as a solvent and were applied to standardized panels. The results show that all samples meet the requirements of the technical parameters, demonstrating good adhesion, appropriate drying times, and acceptable hardness for architectural coatings, Chromatic variations (ΔE*) were recorded depending on the processing method and the level of environmental exposure, with paints containing ground pigments (MG) being more resistant to fading. This study concludes that these artisanal formulations represent a technically viable and culturally relevant alternative to industrial coatings, especially in contexts of heritage restoration or sustainable architecture.

Lime plaster has historically been a key material in the preservation of architectural heritage in Peru; however, its availability has been restricted by state regulations that limit its production and commercialization. This study evaluates the performance of paints formulated with inorganic pigments extracted from soils in the Cusco valley, combined with natural and synthetic binders, as a sustainable alternative for the protection of heritage buildings in this Andean region characterized by high altitude, wide thermal variations, and high solar radiation. Adhesion, hardness, drying time, and weather resistance tests were conducted according to applicable ASTM standards for architectural coatings. The results show that these formulations exhibit good adhesion to historic surfaces and greater durability against extreme environmental conditions compared to traditional lime plaster. Their potential compatibility with historic substrates and lower environmental impact suggest that these paints represent a viable alternative in sustainable conservation strategies; however, further studies are needed to more accurately characterize the mineralogical composition of the pigments used.