The porous nature of lightweight expanded clay aggregate (LECA) is decisive in the physical and mechanical properties of concrete. A comprehensive experimental study consisting of 13 different mixtures and 234 specimens was carried out on density, absorption capacity, porosity, compressive strength, splitting tensile strength, modulus of elasticity, and the effect of moisture state of LECA concrete. Dry compressive strengths of mixtures were found to be between 18–38 MPa, and 9% higher on average than moist compressive strength. Modulus of elasticity values decreased significantly when specimens were oven-dried, where the decrease was 26% on average. The study also includes an evaluation of modulus of elasticity prediction models. All prediction models consistently overestimated dry modulus of elasticity, which is problematic for structural applications of LECA concrete. A unique model for modulus of elasticity prediction was developed as part of the study and verified using independent data from literature for its accuracy.

Ready-mix concrete is not always affordable because it is less economical for small projects. This study shows an effort to introduce alternative home-produced concrete for small paving areas such as sidewalks, backyards, or fixing the existing concrete and discusses the economic evaluation of the alternative concrete for home purpose. The materials being used in this study are available locally or are easily purchased. The primary objective of the study is to analyze the compressive strength and conduct economic analysis of alternative home-produced concrete with different mix designs. Wood ash, fly ash, and recycled aggregate concretes are the alternative concrete types discussed in this study. Fly ash can replace Portland cement up to 30% without losing significant compressive strength of the concrete. Furthermore, fly ash is less expensive than Portland cement and can reduce the cost of concrete by saving approximately 15%. Wood ash can be used up to 25% in concrete without losing considerable strength which saves approximately 13% of cement cost. The use of recycled concrete aggregates saves only about 1% CO₂ emission compared to regular concrete while fly ash saves more than 28.5% and wood ash saves almost 24.5%. They can replace natural aggregates up to 100%, but there is only a 5% saving. In addition, an equivalent cost of USD 13.47 for one cubic yard of concrete could be saved by using 30% fly ash concrete when considering reduced emitted CO_2eq from the material production.

The present impediments to the implementation of sustainable practices in residential and commercial structures in the United States, India and Afghanistan will be evaluated and compared in this study. This study intends to identify the barriers to sustainable development within the residential and commercial buildings creating a basis for the methods to address these issues. The selection of these three countries was based on taking the United States as a developed country, India as developing country and Afghanistan as an undeveloped country. Understanding the barriers studied will establish a path to overcoming them and allow the market to open up to the widespread implementation of sustainable practices. According to the survey conducted, about 91% of respondents in Afghanistan, about 71% in India and 32% of respondents in the USA have moderate to low knowledge on sustainable construction. Other barriers mentioned in the study include the high cost of materials, insufficient training, government policy, and so on.

Connecticut (CT) stands among the top five states for its high electric rates due to limitation in transmission facilities and storage of natural gas. Photovoltaic systems are a growing alternative energy source that reduces the electricity demand and hence higher education institutions should start implementing these technologies to reduce the burden of paying more for electricity bills. The primary objective of the study was to analyze the economic feasibility of solar photovoltaic systems (PV) in higher education institutions in CT. To perform the objective, several economic parameters were calculated and the annual electricity revenue for the University of New Haven was determined and applied to the entire state of Connecticut. The study was expanded to other states in the U.S. by normalizing the available roof area, electricity rate, and solar index by each state. The total electricity generation for various regions by normalization was estimated to be about $651.2 Million annually. With the normalization ratio obtained, one can identify the total power generation in other regions of the U.S. beforehand while considering installation of PV systems. Results from the study regarding the total revenue reveal that the Southwestern and Western regions of the U.S have more solar power generation capacity due to high solar radiation. A life cycle analysis for solar panel was performed at the end to determine how beneficial it is to adopt solar PV in the long run. Considering the recycling of solar PV at the end of its life, additional 4.33% of the total revenue will be expected as benefit, which is quite significant for sustainable option to invest. This reveals that the solar PV is one of significant energy sources and cost saving factors.

The growing number of older bridges has resulted in an increase in structural flaws, demanding frequent inspections and maintenance. Structural degradation accelerates post-damage recovery, emphasizing the necessity of preventive interventions. The use of Uncrewed Aerial Vehicle Systems (UASs) for bridge inspections represents a significant development in structural health monitoring (SHM). Traditional inspection methods are labor-intensive, time-consuming, expensive, and require access to high or difficult-to-reach areas, posing safety risks to inspectors. This study focuses on identifying drones that can efficiently support bridge inspection activities. Key factors influencing UAS selection include flight performance, flying modes, cost, sensor capabilities, payload capacity, and controller communication. The primary objective of this paper is to provide guidance to inspectors and transportation agencies regarding the capabilities and limitations of commercially available drones. It also outlines potential cost considerations associated with drone selection, including pilot skill level, platform cost, and sensor integration. These factors may vary depending on the type and complexity of the bridge being inspected. By addressing these aspects, this paper aims to assist decision-makers in making informed choices regarding the use of UASs for bridge inspection applications.