IoT-based BIM integrated model for energy and water management in smart homes

Increasing urbanization and growth in infrastructure create a demand to utilize modern tools to manage human needs. Effective integration of the Internet of Things (IoT) into the design of smart homes is an actively growing area in the construction industry. The ever-increasing demand and cost of energy require a smart solution in the design stage by the construction industry. It is possible to reduce household energy consumption by utilizing energy-efficient sustainable materials in infrastructure construction. Building Information Modeling (BIM) can provide a solution to effectively manage energy. The integration of the IoT further improves the design of comfortable smart homes by utilizing natural lighting. BIM aids in determining energy efficiency and making decisions by presenting the user with several design options via the 6D method. The present study considered a sample home design following the National Building Code (NBC) and American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) standards for implementation. Natural lighting analysis is carried out with the tool Insight 360 to analyze the energy consumption of the building. Some of the outputs obtained from the analysis are wall-to-window ratio (WWR), window shades, design options for window glass, energy use intensity (EUI), and annual energy cost (AEC). The results of the outputs are compared to find the energy-efficient optimum natural lighting of the proposed building. The lesser EUI (16%–21%) and AEC (23%–28%) are identified with the utilization of low emissivity glass in window panels compared with other types of glass. The proposed IoT-based BIM integration model proves that the effective utilization of natural lighting reduces overall household energy consumption

Utilizing agricultural turmeric bulbs as an alternative to traditional coarse aggregates in geopolymer concrete to explore its engineering properties

Extensive infrastructure development has led to the overexploitation of traditional virgin materials. To preserve the ecosystem, it's crucial to find alternatives. This study explores the viability of using turmeric bulb (TB) as a substitute for virgin coarse aggregate in geopolymer concrete (GPC). With 36 trial mixes varying in activator concentration and curing methods, the aim is to assess TB as a filler material replacement. Experimental trials revealed that replacing up to 20% of the coarse aggregate with TB maintained 28-day compressive strength at 35–38 MPa under ambient curing. However, with oven curing, strength was sustained only up to a 30% TB replacement, beyond which it declined. The UPV value for concrete with 50% TB was 3.79–3.9 km/s. Increasing the activator concentration from 8 M to 16 M significantly enhanced GPC strength, ranging between 24 and 36 MPa. GPC blended with TB showed a higher rate of water absorption, ranging from 24% to 26% for 50% replacement of conventional coarse aggregate. Sustainability analysis revealed that lower activator concentrations (e.g., 8 M) offered a more sustainable alternative to traditional cement concrete. In conclusion, this study underscores the potential of replacing coarse aggregate in GPC, promoting eco-friendly concrete production through sustainable practices and optimized activator concentration

Behavioural studies on binary blended high strength self compacting geopolymer concrete exposed to standard fire temperature

The production of Ordinary Portland Cement Concrete (OPCC) results in high carbon emissions and energy demand, necessitating the search for eco-friendly alternatives. Geopolymers, which utilize waste materials, are identified as a suitable alternative. Industrial by-products such as Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBS), and Metakaolin (MK) are used as precursor materials for binary blended High Self-Compacting Geopolymer Concrete (HSGC) production. Two HSGC mixes and one normal strength self-compacting mix are developed for comparison. This study aims to look at the residual strength characteristics of NSGC and HSGC specimens. Binary blended NSGC, HSGC, and temperature exposure are the key factor examined in the present study. The current study aimed to evaluate the residual strength of NSGC and HSGC exposed to temperature exposure using the ISO 834 guidelines. HSGC specimens are divided into four groups based on curing and cooling type: ambient curing, oven curing, air cooling, and water cooling. Mechanical properties such as Compression Strength, Tensile Strength, and Flexural Strength before and after exposure to elevated temperature are evaluated. Microstructural investigations are conducted to examine the internal structure of the binary blended HSGC mixes. The experimental results are validated using Indian code (IS 456), American code (ACI 318), European code (EC2), and Australian code (AS 3600). Compressive strength of the HSGC specimens was severely reduced when subjected to 1029 ℃, resulting in the formation of wider cracks attributed to the degradation of the gel structure. The oven-cured specimens possess 72 to 80% loss in strength, whereas ambient-cured specimens possess 77 to 86% loss in strength. The findings reveal that the binary blended mix FA/MK = 1 exhibits higher strength loss (%) compared to FA/GGBS and FA. Ambient-cured HSGC specimens exhibit higher mass loss than oven-cured HSGC mixes, and water-cooled samples show higher strength loss and wider cracks compared to air-cooled specimens. The scientific value of this study lies in the the fire performance and residual mechanical properties of binary blended HSGC mixes developed under various curing and cooling methods. Also, the experimental results are validated with multiple international codes (American, Australian and Indian Standards). These findings contribute to the understanding on the behaviour of HSGC under elevated temperature conditions by providing valuable insights for the development of eco-friendly concrete alternatives with improved fire performance

Post-fire flexural behaviour and performance of unrestrained cold-formed steel built-up section beams: Experimental and numerical investigation

Cold-formed steel (CFS) sections are light gauge materials widely used to construct industrial structures. CFS construction is gaining more interest among researchers, construction industries, and structural engineers due to its lightweight and cost-effective design. Fire safety in the building is a significant factor to be considered in the design and construction practices. However, limited studies are reported on experimental and finite element modelling (FEM) of back-to-back built-up channel sections under flexure with unrestrained conditions. Nine back-to-back built-up CFS sections were considered for the experiment. CFS test specimens were exposed to elevated temperatures following the ISO 834 standard fire curve for durations of 30 min (821 ℃), 60 min (925 ℃), 90 min (986 ℃), and 120 min (1029 ℃). After the temperature exposure, air- and water-cooling methods were adopted to cool the CFS specimens. The influence of temperature exposure and cooling affects CFS sections' residual load-carrying capacity and failure behaviour. A detailed physical observation was made after cooling conditions to observe the failure behaviour of CFS specimens. Experiments were performed to evaluate the influence of elevated temperature exposure on the ultimate flexural capacity, moment-deformation behaviour, load-strain behaviour and stiffness of CFS. The moment of resistance results obtained from FEM and the Direct Strength Method (DSM) were validated with experimental results. The experimental results showed that, while increasing the temperature exposure and heating duration, the CFS's load-carrying capacity decreases drastically. In the case of cooling conditions, air-cooled specimens exhibited a higher residual strength capacity, about 10–15%, compared to the water-cooled specimens. A good correlation was noted between the experiment and FEM results in failure modes

Influence of Nano-Fly Ash on mechanical properties, microstructure characteristics and sustainability analysis of Alkali Activated Concrete

Ordinary Portland Cement (OPC) composites significantly affect the atmosphere by emitting Carbon dioxide (CO2) during its production process. The addition of Nano Materials (NM) for the construction could change the matrix configuration at the nano level. Compared to other NMs, converting industrial by-products and locally available materials into nano size can enhance the characteristics of the binder composites. This research work focuses on the effects of Nano Fly ash (nFA), on the fresh, mechanical, microstructural, and thermal resistance properties of Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBFS) based Alkaline Activator Nano Concrete (AANC). The impact of adding nFA in various concentrations of 3 %, 6 %, 9 %, 12 %, and 15 % on the properties of AANC was studied. By adding nFA in an optimal proportion, the degree of geo-polymerization is improved which is found by Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Energy Dispersive X-Ray Analysis (EDAX) and Fourier Transform Infrared (FTIR). Results indicate that the addition of nFA significantly increased polymerization, reducing initial and final setting times by 13.3 %–52.5 % and 5.3 %–28.8 %, respectively. Moreover, nFA promoted the formation of polymer gel, leading to a denser microstructure with fewer cracks and refined pores, resulting in a substantial increase in mechanical strength, particularly with 9% nFA, achieving an optimal CS of 56.14 MPa after 28 days which is 37.97 % improvement compared to the mix without nFA. However, when nFA was added, beyond 9 %, the performances declined due to its high surface area resulting in a non-uniform dispersion that promoted agglomeration. This dispersion enhances the formation of C-A-S-H and C–S–H gels. The addition of nFA in AANC can be an environmentally friendly solution by reducing CO2 emissions, energy consumption, cost reduction and increased sustainability

Influence of coatings on residual strength of geopolymer concrete columns subjected to fire exposure: An experimental investigation

Fires occurring within buildings present a grave concern, as they entail substantial risks to human lives, property, and the environment. Implementing appropriate fire safety measures becomes imperative to mitigate the occurrence of fires and ensure efficient response in the event of an incident. The primary aim of the study is to examine the performance of various coatings on the residual strengths of the reinforced normal strength self-compacting geopolymer concrete (NSGC) and high strength self-compacting geopolymer concrete (HSGC) columns subjected to standard temperature exposure in accordance with ISO 834 guidelines. The design compressive strength of the concretes was 36.12, 57.06 and 52.8 MPa. Two types of coating were employed in the present investigation namely ceramic wool wrapping and high alumina cement. A computerized electric furnace is used to heat the column specimens. Amongst the forty-two columns developed, six specimens tested without temperature exposure and protective coating as a reference specimen. Twelve specimens were heated as per ISO fire curve and tested to assess the residual axial strength performance and twenty-four specimens were coated with protective layers, then heated and tested to assess the post fire performance. It is exemplified that the composite protective coating offers effective resistance to concrete, gaining optimum axial strength performance. The findings show that these fire protecting composites have a high potential for utilizing as new strengthening techniques for reinforced concrete (RC) columns

Influence of protective coating on flexural behaviour of high strength self-compacting geopolymer concrete beams exposed to standard fire temperature

This paper presents an investigation on the effect of protective coatings of high-strength self-compacting geopolymer concrete (HSGC) when subjected to standard fire conditions. The study involved the use of two types of protective coatings, namely ceramic-wool plaster and alumina-bauxite cement plaster, to insulate 42 beams. The findings of this study reveal that employing geopolymer concrete combined with ceramic-wool and alumina-bauxite protective coatings constitutes a significant advancement in fire-resistant construction materials. Specifically, the application of protective coatings to geopolymer concrete beams introduces an additional layer of insulation and fire resistance, resulting in a reduced rate of temperature rise and prevention of spalling and cracking. Both wool-plaster and powder-plaster coating materials exhibit higher heat resistance properties, displaying 2–4 times greater resistance than specimens without protective coatings. The wool-plaster protective coating significantly enhances the residual load-carrying capacity, achieving 97.8% for fly ash (FA)-blended specimens at 821 °C, demonstrating 96.6% and 96.26% for FG (fly ash-ground granulated blast furnace slag) and FM (fly ash-metakaolin) specimens, respectively. Similarly, powder-plaster coated FA and FG specimens exhibit 87.5% and 89.4% residual load-carrying capacity at 821 °C, while FM-blended mix specimens exhibit 89.6%. In specimens subjected to 1029 °C, the residual load-carrying capacity for wool-plaster coated FA, FG, and FM-based specimens was found to be 75.8%, 72.37%, and 69.62%, respectively. Powder-plaster coated specimens exhibited a similar trend with a residual load-carrying capacity of 67.74%, 64.9%, and 66.82% for FA, FG, and FM blends, respectively. Notably, wool-plaster coated specimens proved superior performance compared to powder-plaster coated ones, retaining 75–85% of their strength after 60 min of heating exposure. Conversely, powder-plaster coated specimens retained the same percentage of strength after 30 min of heating exposure. However, an increase in heating intensity and duration led to a decrease in the strength of the concrete mix

Influence of elevated temperature exposure on the interfacial shear strength capacity of binary blended high strength self-compacting geopolymer concrete

The development of sustainable infrastructure is a serious issue faced by modern society. Portland cement is one of the common ingredients in concrete, which influences construction activities. The major issue with the employment of cement in civil-based works is that it is responsible for carbon dioxide emission (CO2-e), the primary greenhouse gas responsible for global warming. Alternative to cement-based concrete, geopolymer concrete (GPC) employs zero cement for concrete production, leading to a reduction in CO2-e. In the case of mass concreting, interface/joints are developed, which are found to be the possible failure spots of brittle fracture. Concrete with different grades (strength) may interface, or other building materials, such as reinforcing materials. The interfacial bond strength has to be examined to ensure the homogeneity of the composite structures. The employment of shear ties at the interface ensures homogeneous behaviour. Moreover, a higher number of shear ties in the shear zone increases the cost of production. The interfacial shear strength (ISS) parameters will be miserably damaged in the concrete structures subjected to fire accidents, which might depend on the intensity of temperature exposure and its duration. The current study investigates the ISS of the High Strength Self-compacting geopolymer concrete (HSGC) in the interface of push-off samples. SCGC was made using binary blended composites, which comprised Fly Ash (FA), Metakaolin (MK), and Ground Granulated Blast Furnace Slag (GGBFS) as precursor materials. The work highlights the need to comprehend the reduction in shear strength of SCGC subjected to high temperatures. The fresh properties of the SCGC composites strictly adhered to the EFNARC guidelines. The SCGC composites, after their curing period, were exposed to 821 ℃, 925 ℃, 986 ℃, and 1029 ℃ following ISO 834 guidelines. Residual mechanical properties were examined after being cooled to room temperature