As the human population grows and technology advances, the demand for concrete and cement grows. However, it is critical to propose alternative ecologically suitable options to cement, the primary binder in concrete. Numerous researchers have recently concentrated their efforts on geopolymer mortars to accomplish this objective. The effects of basalt fiber (BF) on a geopolymer based on fly ash (FA) and basalt powder waste (BP) filled were studied in this research. The compressive and flexural strength, Charpy impact, and capillary water absorption tests were performed on produced samples after 28 days. Then, produced samples were exposed to the high-temperature test. Weight change, flexural strength, compressive strength, UPV, and microstructural tests of the specimens were performed after and before the effect of the high temperature. In addition, the results tests conducted on the specimens were compared after and before the high-temperature test. The findings indicated that BF had beneficial benefits, mainly when 1.2 percent BF was used. When the findings of samples containing 1.2 percent BF exposed to various temperatures were analyzed, it was revealed that it could increase compressive strength by up to 18 percent and flexural strength by up to 44 percent. In this study, the addition of BF to fly ash-based geopolymer samples improved the high-temperature resistance and mechanical properties.

Concrete made with Portland cement is by far the most heavily used construction material in the world today. Its success stems from the fact that it is relatively inexpensive yet highly versatile and functional and is made from widely available raw materials. However, in many environments, concrete structures gradually deteriorate over time. Premature deterioration of concrete is a major problem worldwide. Moreover, cement production is energy-intensive and releases a lot of CO2; this is compounded by its ever-increasing demand, particularly in developing countries. As such, there is an urgent need to develop more durable concretes to reduce their environmental impact and improve sustainability. To avoid such environmental problems, researchers are always searching for lightweight structural materials that show high performance during both processing and application. Among the various candidates, Magnesia (MgO) seems to be the most promising material to attain this target. This paper presents a comprehensive review of the characteristics and developments of MgO-based composites and their applications in cementitious materials and energy-efficient buildings. This paper starts with the characterization of MgO in terms of environmental production processes, calcination temperatures, reactivity, and micro-physical properties. Relationships between different MgO composites and energy-efficient building designs were established. Then, the influence of MgO incorporation on the properties of cementitious materials and indoor environmental quality was summarized. Finally, the future research directions on this were discussed.

Intelligent systems in structural engineering are systems that are capable of automatically adapting structural behavior in response to instantaneous loads, thereby ensuring the safety of extended structural life and performance. One of the new technologies that makes it possible to achieve these goals is the production and development of smart materials. Examples of these smart materials used in structural engineering include piezo-ceramics, magnetorheological fluids, electrorheological fluids, and form-memory alloys. Shaped Memory Alloys (SMAs) are new materials that have been used in various fields of science and engineering in recent decades. In recent years, these materials attracted the attention of researchers in the field of building and earthquake engineering due to their properties such as high damping capacity, low permanent displacement and structural fatigue resistance. One of the application areas of these materials is that they are used as a brace in the structures, so the research results have shown the acceptable performance and operability of such structural systems. In this study, shape memory bracelets and steel bracelets installed as structural brackets were used as a lateral load system in the seismic improvement of concrete bending frames and factors such as residual displacement and base shear in these two load-bearing systems are compared.  The model under studying is a 6-story frame that has been subjected to time history analysis. SeismoStruct software was used to analyze the model.

The authors would like to make the following corrections about the published paper [...]