Concrete is the most-used material in the construction industry, and the second most-used after water. Cement is the main component of concrete. A total of 8% of global CO₂ emissions correspond to the cement industry; CO₂ is the main greenhouse gas contributing to global warming. To mitigate climate change, it is necessary to design buildings with a lower environmental impact, and therefore, it is crucial to assess the environmental profile of the local production of construction materials. This study uses the life cycle assessment methodological framework to evaluate the environmental sustainability of the cement and concrete industry in Ecuador. The inventory accounts for 62.8% of national cement production, with data corresponding to 2019. The OpenLCA software was used to perform the life cycle inventory and impact assessment calculations. Eight impact categories were assessed, including Global Warming Potential (GWP). Clinker has a GWP result of 897.04 kg CO₂-Eq/ton. Hydraulic cement types MH, GU, and HE have GWPs ranging from 465.89 to 696.81 kg CO₂-Eq/ton. Results of ready-mixed concrete range from 126.02 to 442.14 kg CO₂-Eq/m³. Reducing the content of clinker in cement and concrete should be the aim so as to improve their environmental profiles. This study contributes to the development of regional life cycle inventory data for Latin America. This research is the first to be developed regarding construction materials in Ecuador and contributes to the sustainable design of structures with pozzolan-lime cement and concrete.

The use of Supplementary Cementitious Materials (SCMs) or industrial wastes as a partial replacement for cement in the production of concrete is an urgent need in the construction industry due to cement's growing environmental challenges and rising cost. In respect of this, we conducted research work on proportioning binary concrete mixes. Fly ash (FA) replaced 10 %, 20 %, and 30 % of the cement, while silica fume (SF) replaced 5 %, 10 %, and 15 % of the cement. A control concrete mix was also developed with 100 % cement and no SCM. The results showed no increase in compressive strength for FA concrete compared to control at the early age of 3–28 days, but a maximum increase in compressive strength of 4 % was discovered at a later age of 56 days for concrete with 20 % FA. For 5 % SF concrete, a considerable strength increase of 15 % was seen at the early age of 3 days. Like with FA concrete, 2 % improvement in strength was recorded at the later age of 56 days for 10 % SF concrete. This study further focused on the concrete's temporal evolution of compressive strength by developing a strength evolution model (SEM) using nonlinear regression analysis at a 95 % confidence level. Pearson correlation coefficient was used to determine the correlation between the model values and the experimental results. For comparison, the fib Model Code 2010 was applied to the experimental data, and a good agreement was observed among the proposed model, the fib Model values, and the experimental results. The proposed model can be expanded to address further regression-related problems. Finally, environmental life cycle assessment revealed that utilizing 10 %, 20 %, and 30 % of FA lowered Global Warming Potential (GWP) by 9 %, 19 %, and 29 %, respectively. Likewise, using 5 %, 10 %, and 15 % of SF reduced the GWP by 5 %, 9 %, and 14 %.

The use of natural fibers including abaca has increased because of its advantages such as lightweight, low price, life-cycle superiority, and substitute for synthetic fibers. This paper gives an insight into the effect of three different treatments on abaca fibers: hornification, NaOH 3% concentration solution, and a coating of silica fume with natural latex into cementitious composites; fibers have been characterized before and after through SEM, XRD, FT-IR, TGA, and tensile tests to analyze structural and chemical changes. Cementitious composites through setting time and flexural strength (7, 14, 28 days) were analyzed for determining the optimum treatment and, afterward, the best dosage and length. It was found that HS treatment with 30 mm and 0.2% dosage showed 8.2 MPa in terms of flexural strength.

Global warming is the greatest environmental challenge that humanity is phasing. Water availability and biodiversity are also important issues of concern. Efforts towards achieving a sustainable path are required in all major sectors. The construction and infrastructure sector is an important contributor to global resource depletion and environmental impact. Life cycle assessment (LCA) is a frequently used tool to assess the potential environmental impact of a product or service throughout its life cycle. The life cycle of a product involves the extraction of raw materials, processing, production, use, and end-of-life. The environmental performance is quantified according to several impact categories such as: global warming, abiotic depletion, acidification, eutrophication, ozone layer depletion, photochemical oxidation, among others. LCA has been applied with success in the construction and infrastructure sector, in particular for buildings of all types. Literature in LCA of buildings use a variety of methodological approaches. The objective of this literature review is to identify and compare the different methodological approaches used in LCA of residential buildings, with a particular focus on functional unit, system boundaries, environmental impact categories, and data quality. The review indicates that there are different approaches used depending on the objective of each particular study.