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Energy consumption in residential buildings soared enormously during the pandemic. To construct highly efficient residence, materials are one of factors that need to be considered due to their impact of climate change, power consumption and operational cost. It was found that power plants produced various types of waste products that can be utilized in many applications. For instance, Cenosphere produced from power plants could promote thermal properties of mortar brick to a certain extent. The aim of this study is to evaluate the effects of Cenosphere as partial sand replacement on thermal properties of mortar and buildings’ energy efficiency at different percentages (0%, 5%, 10%, 15% and 20%). Both thermal conductivity and specific heat capacity were detected by using Fox 50 instrumentation while energy efficiency was determined by using Autodesk Revit and Green Building Studio (GBS) software. The findings of thermal properties show that the replacement of sand with 20% Cenosphere as partial sand replacement have significantly reduces thermal conductivity while increasing the specific heat capacity of mortar. This study revealed that the k value of mortar bricks have reduced as low as 0.62 W/m.K and as high as 932 J/kg.K for specific heat capacity due to incorporation of Cenosphere and mixtures at 20%. On the other hand, the EUI of 5% Cenosphere has reduced 2.13 kWh/m2 or 1.4% lower than control mix. The energy saving measure largely influenced by the composition of Cenosphere as compared to the buildings’ orientations.

Coal combustion by Products (CCPs) are produced during coal combustion in the process of electric generation. Without proper handling system, this will cause serious problems towards human and environmental. Nevertheless, with proper treatment, these ashes are applicable in many areas specially building construction materials. Coal Bottom Ash, Coal Fly Ash and Cenosphere are three main wastes produced from power plant. The aim of this study is to determine the characteristics of samples collected from different parts of Malaysia Power Plant. Characterization testing involved included surface morphology, chemical composition (oxides), chemical components, amorphousness, and particle size distribution testing. From this study, CBA have more angular-shaped particles compared to CFA which is smoother surface morphology. However, Cenosphere shown the most uniform and spherical shaped particles. EDS testing shown Existing CBA have highest Carbon content (46%) while Cenosphere is lowest (11.38%). The percentage oxides contents for all samples demonstrate more than 70% of Total SiO2 + Al2O3 + Fe2O3. Hence, all ashes considered as Class F (pozzolanic). CBA, SFA, CFA and cenosphere has significantly more amorphous phases of silica and alumina, and this will increase the concrete strength. Due to agglomeration of ashes on ash pond, the cumulative PSDs results shown that the particle size of the existing sample obtained larger than the new sample. Minimum particles size of SFA (New Dry) is 2 µm while SFA (Existing 2) is 20 µm. From characteristic determination above, it shown that each type of ashes has its own uniqueness and capability to be applied wide range of applications.

The escalating demand for construction materials, coupled with the depletion of natural resources such as sand, necessitates environmentally conscious alternatives in concrete production. This study investigates the viability of utilizing bottom ash as an eco-friendly substitute for natural sand in roller compacted concrete (RCC). The focus is on evaluating workability and mechanical properties, examining bottom ash replacements at 0%, 20%, 25%, and 30% for fine aggregate. The research employs a comprehensive methodology, assessing workability and mechanical strength, encompassing compressive, split tensile, and flexural strengths across various concrete formulations. Comparative analyses with conventional concrete provide conclusive insights. Significantly, the study consistently highlights the superiority of RCC specimens featuring a 25% bottom ash replacement, exhibiting the highest strength values. This establishes the 25% replacement ratio as optimal for achieving robust roller-compacted concrete. Despite a slight reduction in workability with increasing bottom ash replacement, it remains within acceptable limits for practical applications. Comparative analyses between bottom ash RCC and conventional RCC underscore the superior mechanical attributes of the former, suggesting its potential as a sustainable alternative in concrete construction. By substituting natural sand with bottom ash, this research addresses environmental concerns related to the depletion of sand reserves. It actively contributes to sustainable practices within the concrete industry, demonstrating the viability of bottom ash as a substitute for natural sand in roller compacted concrete production. In conclusion, the study advocates for environmentally friendly practices and offers a practical solution to mitigate the ecological impact of sand resource depletion in the realm of concrete construction. The findings emphasize that the optimum percentage of bottom ash for compressive strength, split tensile strength, and flexural strength tests is within the range of 0% to 12%.

Nature inspires innovative renewable energy solutions by advancing our road pavements, as the sun is the only infinite and accessible source of clean and green energy on our planet. In addition to the various solar energy production methods, a new paradigm for utilizing asphalt pavement as a solar collector is being developed for self-powered energy harvesting. Due to direct solar radiation, flexible paved surfaces exposed to direct sunlight can heat up to 70°C in the summer. The heat is then dissipated into the environment, causing the urban heat island effect, and accelerating thermal oxidation of asphalt pavement. This can lead to structural failure and reduced pavement performance. This study aims to present a state-of-the-art review of hydronic asphalt solar collectors (HASCs) and propose the best model to enhance the performance of asphalt solar collectors. The findings of the study concluded that asphalt has the potential to absorb solar energy and store heat energy. This can be achieved by assembling and modifying conventional asphalt structures into modern asphalt solar collector designs that consist of pipe arrangements below the paved surface filled with liquid flowing through the pavement surface. The study found that a significant limitation of previous research was that it focused on optimizing the temperature profile at various depths but did not focus on structural improvements to reduce failure and increase the performance of asphalt solar collectors. Therefore, this review study proposed a new technique of using conductive and waste materials to enhance the performance of asphalt solar collectors.

This study aimed to investigate the characteristics of roller-compacted concrete when fine aggregate is replaced with fly ash. The investigation focused on assessing workability, compressive strength, flexural strength, and split tensile strength of the concrete mixtures. Four testing methods were employed, including the slump test for workability assessment, the compression test for determining compressive strength, the flexural test for evaluating flexural strength, and the split tensile test for measuring split tensile strength. The fly ash used in this project was sourced from the powerplant in Malaysia. Various fly ash contents, specifically 0%, 55%, 65%, and 75%, were utilized to replace the fine aggregate. The concrete mixtures were subjected to water curing for 7, 14, and 28 days before testing. Following the mixing process using a concrete mixer, the mixtures underwent a slump test to evaluate their workability. It was observed that the workability of the concrete decreased as the percentage of fly ash used to replace the fine aggregate increased. Mixtures with fly ash exhibited zero slump, while the control mixtures displayed true slump. Subsequently, compression, flexural, and split tensile tests were conducted after 7, 14, and 28 days of water curing. In terms of compression strength, an increase in fly ash content resulted in higher compressive strength in the concrete mixtures. The mixture with 65% fly ash content demonstrated the highest compressive strength at 49.84 MPa. Regarding flexural strength, the concrete with 75% fly ash content exhibited the highest value, measuring 5.45 MPa. However, for split tensile strength, the concrete without fly ash content showed the highest value at 8.84 MPa compared to other mixtures, indicating that the fly ash content exceeded the optimum amount for the mix design. In summary, the concrete mixtures with fly ash displayed several advantages, but their suitability depends on the specific type of construction.

The research aims to investigate SCGC performance as a suitable alternative to the traditional concrete. The research will study the effect of LWCA, steel fiber and curing condition on the fresh and hardened properties of SCGC. The main materials will be used for SCGC are fly ash and slag. Curing will be performed using oven, and ambient temperature. Steel fibers SF will be incorporated into the mixture at 0%, 0.5%, 1% and 1.5% of binder content. While the natural coarse aggregate will be replaced by LWCA with 0%, 33.3%, 66.67% and 100% by weight. Analysis of this (SCGC) were done for both fresh and hardened state to assess the mechanical properties of (SCGC). This study finds that the addition of both LWCA and SF decreased the blend's L-Box ratio and slump flow value. All SCGC mixtures fulfilled the EFNARC guidelines and standards. Results reported that Mixes with a greater percentage of LWCA and SF became more cohesive and viscous. Results revealed that the SCGC exposed into ambient air curing condition had lower flexural strength, compressive strength, and tensile strength than of heating curing condition. The compressive strength CS of samples(M1-M9) exposed to heating conditions compared to the ambient ones increased about 36.09%, 26.32%, 17.88%, 23.87%, 27.96%, 27.69%, 38.94%, 27.91% and 24.53% respectively. The better CS values were 38.94% for M7 mix and 36.08% for M1 Mixtures. The FS of samples exposed to heating conditions compared to the ambient ones increased about 13.39%, 13.39%, 23.78%, 18.64%, 17.85%, 11.67%, 34.70%, 8.65% and 12.24% respectively the better flexural strength value was 34.70%, of M7 mix exposed to heating conditions. The better TS value was 26.22 Mpa for M3 Mixes at 1.5% of SF, While the TS reported dropping about 38.4% when applying LWCA as partially replacement of 66.67% with ambient curing condition. The study findings that the (CS) of mixes were proportional directly with steel fibers percentage till (1.0%). The CS, FS and TS of SCGC decreased when increasing LWCA. As a result, the SCGC that cured in oven showed enhancement in each fresh and mechanical properties, therefore, it is recommend to utilize the (SCGC) in hot areas and utilize wastes such as steel fibers and LWCA in SCGC as an economic, affordable and eco-friendly material. [ABSTRACT FROM AUTHOR]

Attapulgite is a natural clay mineral, that has been investigated as a potential lightweight aggregate due to its low density and unique structural properties. Recently, the interest in using attapulgite has increased. In this study, the combined attapulgite (fine and coarse) is used in a concrete mixture. Tests were conducted to select the best content of attapulgite in mixtures by investigating its properties, including slump, compressive strength, and density characteristics to evaluate Lightweight Concrete (LWC) performance. The outcomes exhibited that different attapulgite aggregate contents influence compressive strength, with the highest value being 21 MPa for 984 kg/m³ attapulgite content at 28 days of curing. Furthermore, the dry density is positively correlated with the increment of the attapulgite aggregate percentage. Then, different percentages of Superplasticizer (SP) of 0.9%, 1.1%, 1.3%, 1.5%, and 1.7% were utilized, which led to the enhancement of the slump flow. The ideal ratio adopted for the subsequent mixtures was 1.3% by weight of cementitious material, which gave the highest compressive strength (26.2 MPa at 28 days). Also, mixtures in which cement was replaced by fly ash of 10%, 20%, 30%, 60%, and 100% ratio by weight of cement were prepared. The results demonstrated that the highest compressive strength was 32.7 MPa with a 30% ratio of fly ash by weight of cementitious materials after 90 days of curing. [ABSTRACT FROM AUTHOR]

One of the most crucial ecological challenges is the removal of the ever increasing enormous quantities of Fly Ash (FA) generated from various industries and its reduction in landfill spaces. Light-Weight Aggregate Concrete (LWAC) is utilized in the construction industry as it can decrease the unit weight leading to lower dead load, thermos-insulation, and resistance against earthquakes. A number of researchers have implemented experimental programs on the use of large amounts of FA as a substitute for cement in various lightweight concrete mixtures. This study aims to present the recent efforts of adding attapulgite in LWAC and highlight its effects and the influence of its mixture with High Volume FA Light-Weight Concrete (HVFALC) in terms of compressibility resistance, tensile strength, and rupture resistance. [ABSTRACT FROM AUTHOR]

There has been a significant interest in the development of eco-friendly building materials. Recyclable and environmentally friendly, geopolymer composites are extraordinary binding materials. The purpose of this experimental study was to examine the mechanical and durability properties of metakaolin based self-compacting geopolymer concrete (SCGPC) comprising steel fibers (SF) and recycled aggregate concrete (RCA) varying percentages of recycled coarse aggregate. The mechanical and durability properties of the geopolymer composites, including fracturing tensile strength, and flexural strength, were subsequently evaluated. At weight proportions of 0%, 25%, 50%, 75% and 100%, the recycled coarse aggregates were substituted for the natural coarse aggregates. The amounts of SF incorporated into the mixtures were 0, 0.5, 1.0, and 1.5% by volume fraction. While the incorporation of SF does not yield a substantial improvement in compressive strength, it substantially enhances fracture tensile strength and flexural behavior. The load-displacement graph demonstrated that the incorporation of steel fibers into geopolymer composites increased their fracture toughness, resulting in a higher maximal load capacity. The findings suggest that the incorporation of RCA into SCGPC reduces its flexural behavior, splitting and compressive tensile strengths, and durability, particularly under peak load, deflection, and load. Furthermore, it is observed that RCA negatively synergize with respect to compressive and fracturing tensile strength. However, SF exhibit a significant positive synergy in terms of flexural properties. [ABSTRACT FROM AUTHOR]

The manufacture of cement plays a substantial role in the emission of carbon dioxide (CO2) into the atmosphere, hence exacerbating the adverse impacts of global warming. Consequently, the emergence of Geo-Polymer concrete has presented itself as a potentially feasible substitute owing to its commendable environmental sustainability. This manuscript provides a comprehensive analysis of prominent studies investigating the effects of increased temperatures and fire exposure on concrete across its entire operating duration. This study examines the significant impacts on the fundamental physical and mechanical characteristics of concrete, as revealed by laboratory experiments. Furthermore, this review comprehensively examines previous research endeavors that have used machine learning methodologies to predict tangible actions, aiming to optimize resource allocation, time efficiency, and cost-effectiveness in laboratory inquiries. Geo-Polymer concretes have exhibited remarkable resistance to elevated temperatures and severe fires, as evidenced by laboratory and field assessments of cracking, spalling, and strength degradation. Prior studies have demonstrated that both the aggregate type and temperature have a substantial impact on the degradation of compressive strength. Moreover, previous research has indicated that Geo-Polymeric concrete, which is comprised of fly ash, exhibits superior heat resistance compared to conventional concrete using Portland cement, withstanding temperatures of up to 400 degrees Celsius. This research also highlights the widespread adoption of the Artificial Neural Network (ANN) technique in forecasting the compressive strength of conventional concrete. Conversely, alternative approaches such as the Genetic Weighted Pyramid Operation Tree (GWPOT) are preferred for high-performance concrete. The primary objective of this extensive investigation is to establish a fundamental basis for future studies on sustainable alternatives to concrete and approaches for predictive modeling. [ABSTRACT FROM AUTHOR]