The potential for long-term deflection to govern the serviceability of flanged beams results from the combined effects of the sustained loading on the beams, as well as factors like cracking, creep, and shrinkage that contribute to the reduction of the margin between calculated and prescribed deflection limits. While deterministically determining the deflection of beams ensures that the deflection specification is satisfied, no information is obtained regarding the probability that the beam will experience deflection that reaches the prescribed limit state. Eight flanged beams of various section depths were evaluated, each with a span length of 5,000 mm. For each beam, the total deflection limit of l/250, or 20 mm as prescribed in the Indian standard code IS 456:2000 was utilized to define the serviceability limit state. Additionally, the limit state can be defined in terms of the individual components of deflection: instantaneous, shrinkage, and creep. Eighteen structural and material variable characteristics were determined for each of the eight beams. For the reliability analysis, eight of the variables were utilized: the sustained bending moment, the span length, the elastic modulus of the concrete, the effective moment of inertia, the shrinkage curvature of the beam, the modulus of elasticity of the concrete that has been creep-modified, the long-term effective moment of inertia, and the moment that is applied to the beam under the sustained load. The reliability of each beam was calculated using the First Order Second Moment (FOSM) method, as well as Monte Carlo simulation utilizing 100,000 samples to determine the reliability of each beam. Furthermore, methods were utilized to determine the local sensitivity of the beams, including analyzing the inclusion of variables, the suppression of individual variables, and the importance of the variance of each variable. Results of the analysis indicate that as the tabulated depth of each beam decreases from 450 mm to 310 mm, the mean total deflection of each beam increases from 10.464 mm to 16.982 mm, or an increase of 62.3%. Additionally, the reliability of each beam calculated via FOSM indicates that as depth decreases, the FOSM reliability index decreases from 4.634 to 1.018, with the corresponding failure probabilities increasing from 1.79×10−6 to 1.54×10−1. Monte Carlo method results indicate that the mean total deflection of each beam increases from 10.547 mm to 17.131 mm, an increase of 62.4%, and that the failure probability increases from 5.00×10−5 to 1.37×10−1, with reliability indices of 3.891 and 1.094, respectively. Comparison of the two methods indicates that the FOSM approximation is non-conservative for the deeper sections, returning a reliability index 19.1% above the simulated value at a depth of 450 mm, and mildly conservative for the shallowest sections, returning a value 6.9% below the simulated one at a depth of 310 mm, the sign of the deviation changing at an effective depth of approximately 340 mm. Additionally, each of the variables related to the sustained load on the beams contributed to approximately 60.3% to 65.8% of the total deflection of each beam. Furthermore, analysis of each of the eight beams indicates that the shallowest depth of 410 mm is the shallowest depth of any of the beams studied at which each method achieved a reliability index of 3.0 or more; thus, the depth-to-reliability relationship is only preliminary and should be applied to beams of the same span length, similar material properties, similar support conditions, and with a sustained load of 40%. A more thorough application of these methods to other beams would require additional experimental validation of the results.
Unsustainable extraction of river sand has caused widespread ecological damage and created an urgent need for alternative fine aggregates. Iron Ore Tailings (IOT), generated in bulk during iron ore beneficiation and presently managed by stockpiling, constitute a candidate waste stream for valorisation in cementitious systems. This study evaluates IOT as a replacement for manufactured sand in mortar and structural concrete using a hierarchical mortar-to-concrete optimisation framework. Cement mortars were produced at IOT replacement levels of 0 to 100 per cent and water-cement ratios of 0.40, 0.50 and 0.60 at a 1:3 binder-to-aggregate ratio, and the optimum identified at mortar scale was transferred to M25 concrete cast at water-cement ratios of 0.50 and 0.60. Replacement of 40 per cent of the manufactured sand raised the 28-day compressive strength from 35.24 to 39.02 MPa at a water-cement ratio of 0.50, a gain of 10.7 per cent that remains statistically significant for any within-triplicate coefficient of variation up to 4.49 per cent. Flexural capacity was preserved rather than improved, and the reductions in splitting tensile strength of 8.4 and 7.6 per cent and in slump of 9.6 and 8.3 per cent, although consistent in direction, lie within the typical precision of those tests at three replicates. Charge passed decreased monotonically from 160 to 144 coulombs across 0 to 60 per cent replacement, all mixes remaining within the very low permeability class of ASTM C1202. A second-order response surface fitted to the mortar means places the stationary point at 27 to 30 per cent, and the optimum is accordingly reported as a range of 30 to 40 per cent rather than as a sharp maximum. The strength gain is attributed to packing densification and capillary void refinement rather than to pozzolanic reaction, an interpretation supported by the low calcium oxide and amorphous contents of the tailings and benchmarked against published pore structure and interfacial transition zone data for comparable IOT concrete. Cradle-to-gate assessment gives a 1.1 per cent reduction in global warming potential per cubic metre, a 10.7 per cent reduction in carbon intensity per megapascal and a 7.6 per cent reduction if the strength margin is reinvested as a binder reduction, with material cost falling 5.4 per cent per cubic metre within a break-even haul distance of about 200 km. IOT is therefore established as a technically competitive and environmentally preferable fine aggregate for structural concrete.
Hospital buildings constitute a large commitment, both financially and operationally, over their service lives. Therefore, the decisions about the construction material compel a consideration of the initial construction costs and the future costs associated with the maintenance and the replacement of the construction. Material selection in construction, however, is characterized by a strong focus on the first costs, bending the economics for the overall construction lifecycle. Value Engineering integrated with Life Cycle Costing presents a more robust framework for comparing construction options. This study examines the architectural component of the Hermana Lembean Hospital project. This study combines VE and LCC for a single framework assessment. The primary data source was the project’s Bill of Quantities, technical specifications and drawings. A Pareto analysis was first used to identify the primary cost elements, and then, the VE job plan was used to develop and assess material options. The selected alternatives were then assessed using a 20-year LCC analysis with an annual discount rate of 8%. The results show that architectural work is the largest cost component, amounting to Rp 2,456,544,915.00 or 38.93% of the total project cost. The implementation of VE reduced the initial cost from Rp 924,197,538.00 to Rp 893,603,302.00, resulting in a cost saving of 3.31%. Meanwhile, the total LCC decreased from Rp 1,239,146,878.51 to Rp 1,138,403,872.00, resulting in a saving of 8.13%. The best alternatives were lightweight brick, ready-mix mortar, Nippon Paint, Nippon Weather bond, and GRC ceiling panels. This study demonstrates that the integration of VE and LCC can produce more efficient decisions than considering only initial costs.
Waffle slabs are widely used in modern construction because they can span large distances while reducing material consumption and overall structural weight. Despite these advantages, their relatively low lateral stiffness can become a major source of seismic vulnerability, especially when simplified assumptions such as the rigid diaphragm model are adopted in structural analysis. This study examines the seismic response of waffle slab systems, with particular attention to the influence of diaphragm flexibility on displacement amplification and damage concentration around slab–column connections. The findings indicate that inadequate in-plane stiffness can generate excessive interstory drift, dynamic amplification effects, and progressive deterioration of slab–column interfaces, ultimately reducing the overall seismic performance of the structure. The research combines previous literature, post-earthquake observations, and advanced numerical simulations to identify the main mechanisms responsible for seismic vulnerability in waffle slab structures. Reported damage patterns include extensive cracking, formation of plastic hinges, bond degradation, and progressive punching shear failure, which in severe cases may result in partial or complete collapse. To better evaluate these effects, an advanced numerical framework is proposed to assess the seismic capacity of waffle slabs and investigate the causes of their reduced lateral stiffness. In addition, a Seismic Fragility Index for Slabs (SSFI) is introduced to quantify vulnerability and classify waffle slab systems according to regional seismic hazard levels. The adopted methodology integrates modal analysis, nonlinear static (pushover) analysis, and nonlinear time-history simulations. A comparison between rigid and flexible diaphragm models highlights the significant influence of slab flexibility on both the overall seismic response and the distribution of structural damage. The findings show that adopting the rigid diaphragm assumption can substantially underestimate displacement demands and overlook critical failure mechanisms, resulting in unconservative seismic evaluations and an increased probability of structural failure.
The use of concrete as the primary building material for infrastructure is widespread. The structural components of concrete tend to crack due to a variety of factors. These cracks allow harmful substances such as water, chlorides, sulfates, and carbon dioxide to enter the concrete and cause it to deteriorate. The maintenance and repair of cracked concrete increases the cost and ecological impact of constructing and operating these infrastructures. One way to manage this problem is to create Self-Repairing Concrete using biological materials. Several types of bio-based self-healing agents have been developed, and many have been verified in concrete. One such approach is called Microbially Induced Calcite Precipitation (MICP). This technique uses certain bacteria, such as Bacillus subtilis, that can survive within the concrete in a dormant state. Once the concrete is placed and water is introduced, these dormant bacteria become active. The bacteria secreted calcium carbonate fills the fissures in the concrete. The primary goal of this research was to use Bacillus subtilis to create bacterial concrete that heals itself. M25-grade concrete as per Indian Standards was used to prepare three types of concretes. The control concretes contained 0 cells/mL (M0). Bacterial concrete contained 10⁵ cells/mL (B1) and 10⁶ cells/mL (B2). The properties that were tested included workability, strength of compressive, split-tensile, and flexure, along with durability in alkaline-acidic environments. The results obtained indicate that the use of bacteria significantly improves the mechanical properties of concrete and durability. All of the bacterial concretes exhibited increased tensile, flexural and compressive strength. The B2 mix (10⁶ cells/mL) exhibited the highest 28-day compressive strength. The durability tests indicated that bacterial concrete resists chemical deterioration better than conventional concrete. This study confirms that bacterial Self-Repairing Concrete is a sustainable substitute to usual concrete repair. The ability of bacterial concretes to autonomously seal microcracks and increase the durability of the concrete indicates that such concretes have great potential to be utilized in constructing long-lasting and low-maintenance infrastructures.
This study analyzes the combined effects of dolomite powder (DP) and Sugarcane Bagasse Ash (SCBA) used as a binary auxiliary binding composition on M30 grade concrete to enhance its mechanical behavior, durability, and microstructure stability when subjected to aggressive environment conditions. Five different concrete specimens have been fabricated using replacement rates varying from 0% to 30% for DP and SCBA mixture ratios. The experimental studies consist of compressive strength, flexural strength, stress-strain relationship, Elastic Modulus, water absorption, chemical durability during acid attack, and X-ray diffraction (XRD) phase investigation. It was observed that specimen M3 with 10% DP and 5% SCBA mixture attained the maximum values of 28 days compressive strength as 47.84 MPa, flexural strength as 4.84 MPa, Young’s modulus as 17400 MPa, and the minimum value of water absorption as 3.52%.
Estimation of seed moduli accurately are very important for conducting reliable backcalculation of layer (Bituminous, granular, subgrade) moduli using data generated by Falling Weight Deflectometer (FWD). This research presents an effective Deflection Basin Parameter (DBP)-based correlation method for predicting seed moduli of flexible pavement layers at various distress levels. FWD tests were performed on three pavements having different distress levels in different parts of India. A database consisting of 7000 pavement responses was created with the help of IIT-PAVE software by taking into account different thickness and modulus combinations of layers. Regression models were formulated in order to find out correlations between DBPs and layer moduli (ML) of bituminous, granular, and subgrade layers. The formulated regression models were validated via backcalculation analysis using KGPBACK software and compared with the Abd El-Raof et al. (2018) technique. It was found that the proposed correlation models provided excellent prediction with the R-squared (R²) of 0.96, 0.95, & 0.81 for bituminous, granular, and subgrade layers, respectively. Validation of the models revealed that they showed smaller RMSE of 2.4% to 9.1% as compared to 4.2% to 10.8% found by the existing method.
Due to its contributions to the emission of greenhouse gases, the depletion of topsoil, and the consumption of non-renewable energy resources, the fired clay brick industry is under considerable scrutiny. The investigation of unfired Geopolymer-Stabilized Earthen Bricks (GSEBs) with binder matrices comprised of Class F fly ash and Alccofine 1203 and alkali activators of 6 M NaOH and Na₂SiO₃ in a 1:2.5 molar ratio, using Tank Bed Soil (TBS) and Gold Mine Tailings (GMT) as the primary aggregates in each brick, revealed that the blocks produced with the optimized mix of Binder:Liquid:TBS:GMT = 1:0.3:1.8:1.2, cured in an oven at 58°C for seven days achieved compressive strengths between 6.8 and 11.3 MPa - values that meet the minimum requirement of 3.5 MPa for first-class masonry blocks and compete with fired clay bricks. Geotechnical analyses of the aggregates and the produced GSEBs are presented. A modified cradle-to-gate assessment produced an estimated embodied energy of 1,150 MJ/m³ under the stated waste-allocation, process-energy and scale-normalized oven-curing assumptions. This value was approximately 54.3% lower than the adopted historical benchmark for burnt-clay brick. The main source of energy for GSEBs is from the synthesis of the alkaline activators of NaOH and Na₂SiO₃ at energy values of 20.5 MJ/kg and 5.37 MJ/kg, respectively. These results indicate that using mine waste to produce GSEBs is an environmentally friendly alternative to conventional forms of masonry construction, especially in areas near the Kolar Gold Fields and thermal power stations.
Nowadays, research has increasingly focused on alternative additives that enhance the sustainable performance of Pavement Quality Concrete (PQC), enhanced by the growing demand for eco-friendly pavement materials. This study explores the viability of using wood powder as an Internal Curing (IC) agent in PQC through FEM modelling by using the experimental results obtained. From the laboratory experimental results, only the optimum replacement level of wood powder (9.6%) in IC concrete mixes (i.e., IC-9.6% and IC-9.6% ALC 20%) as a partial replacement of fine aggregate is considered and compared with conventionally cured concrete mixes. Fresh properties such as slump, mechanical properties including compressive strength and flexural strength, and durability properties such as density and sorptivity of these mixes are discussed, along with correlation graphs of the results. The micro investigation, such as FESEM, is also discussed to verify the results obtained. These results are then used for pavement modelling (FEM Modelling) for single axle load (i.e., 10.2 tons) to forecast structural reactions and service life enhancements with the amended concrete mix. Fatigue life of pavement on the basis of stress ratio was calculated, and an economic analysis is also done to estimate the life cycle cost of wood powder-modified PQC with those of traditional mixes. The study’s conclusions show that employing wood powder as an IC agent in pavement construction offers an economical and eco-friendly way to improve infrastructure performance. It also has the added advantage of lowering water waste through ready-made curing processes in the world of water scarcity.
This study extends the design space of pervious concrete with respect to strength, drainage, and water purification using a multi-objective optimization approach. GGBS was used as a partial cement replacement (15–45%) across four no-fines coarse-aggregate gradations and assessed for compressive strength (accelerated, 7-day, and 28-day), constant and falling head permeability, and water filtration. The optimal formulation - a 60:40 blend by mass of the 16–10 mm and 10–4.75 mm coarse-aggregate fractions, with 30% GGBS - develops a compressive strength of 11.78 MPa at 7 days rising to 18.83 MPa at 28 days, together with a measured permeability coefficient of 2.0 mm/s and removals of 23.8% of dissolved solids and 10.2% of suspended solids. Microstructural images from SEM and porosity specifications indicate that slag modification densifies the interfacial transition zone without impeding drainage. Structure–property relationships align with previous studies indicating the presence of a design space with an optimal strength target for multifunctional properties. This evidence demonstrates that microstructural optimization via slag enables simultaneous structural and environmental performance, thereby promoting the use of pervious concrete in urban infrastructures.
Civil infrastructure assets are managed today through inspection cycles and calendar-based interventions that observe an asset only at discrete instants, so deterioration between visits is inferred rather than measured. Digital Twin (DT) research has addressed parts of this problem, but published frameworks remain confined either to a single lifecycle phase or to a single enabling technology, and few report reproducible validation against public benchmarks. This paper presents a unified DT framework that couples a cyber-physical sensing and communication layer, an entropy-weighted multi-sensor fusion scheme, a hybrid physics-plus-machine-learning surrogate, extended Kalman assimilation for continuous model updating, and a constrained multi-objective optimisation layer that closes the loop from measurement to intervention across all five lifecycle phases of an asset. The contribution is threefold: a phase-invariant state formulation in which design, construction, operation, maintenance and end-of-life are expressed as a single evolving state trajectory; an adaptive physics-to-data blending coefficient calibrated on held-out data rather than fixed a priori; and a reliability-constrained decision layer in which maintenance actions are selected subject to an explicit failure-probability bound. The framework is exercised on a provisional synthetic dataset generated deterministically from a calibrated finite element model of a three-span reinforced concrete girder bridge, and is benchmarked against traditional, IoT-only and AI-only baselines under an identical protocol. All reported results are simulation outcomes; no field validation, laboratory validation or real-time deployment has been performed. The DT configuration attains 96.0% detection accuracy, with a 95% Wilson interval of 95.0 to 96.8, and an area under the curve of 0.98, against 90.0% and 0.92 for the strongest AI-only baseline, every pairwise difference being significant at p below 0.001 after Holm-Bonferroni adjustment. Remaining useful life error falls from 4.80 to 1.30 years, median end-to-end latency from 250 ms to 120 ms, and the annual failure rate from 0.080 to 0.020, raising twenty-year reliability from 0.202 to 0.670 with a discounted break-even at year 5.8. Detection accuracy remains at or above 92% across high-temperature, heavy-load and seismic operating states. A component ablation attributes the margin principally to environmental normalisation at 7.4 percentage points, the physics constraint at 6.0 and continuous assimilation at 4.8, rather than to model capacity, which is held constant against the AI-only baseline. Deployment barriers - interoperability, cybersecurity, cost, power and validation under uncertainty - are quantified and mapped to mitigation measures and residual risk, and a reproducibility statement specifies the dataset generator, splits, hyperparameters, seeds and computing environment, from which every reported figure is exactly reproducible.
Concrete gravity dams constitute critical hydraulic infrastructures whose seismic response is crucial for maintaining structural stability and safety. The present study investigates the performance of three machine learning algorithms, namely Multilayer Perceptron (MLP), Support Vector Regression (SVR), and Extreme Gradient Boosting (XGBoost), for predicting the maximum seismic displacement of concrete gravity dams within a Single-Degree-Of-Freedom (SDOF)-based seismic reliability framework. A dataset comprising 304 samples was generated through parametric finite element simulations by varying the principal geometric and material properties of the dam system. The predictive performance of the models was evaluated using six-fold cross-validation based on the coefficient of determination (R²), Root Mean Square Error (RMSE), and Mean Absolute Error (MAE). Among the evaluated algorithms, MLP achieved the highest prediction accuracy, whereas XGBoost demonstrated comparable performance. SHAP and perturbation-based sensitivity analyses consistently identified dam height as the most influential parameter governing the predicted seismic displacement. The proposed framework provides an efficient and interpretable approach for rapid seismic displacement prediction and seismic reliability assessment of concrete gravity dams.
Existing large stormwater detention pond outlets are designed to cater for high flow, for example, due to 100-year ARI design storms. As such, the outlets are usually large, which are unable to detain smaller storms. To improve the outlet design to have dual function to sustain both small and extreme storms, a new outlet design is proposed with two separate orifice openings within a single outlet. An early investigation was conducted by applying a case study, in which a real-life detention pond was selected and simulated in Storm Water Management Model embedded with scenarios of existing outlet with 0.45 m diameter orifice opening, and another with proposed 0.1 m diameter orifice opening before the existing orifice. The model was run through with 10-year ARI design storm according to the local equatorial climate. The modelled outflow indicated that the existing orifice produced a peak of 0.35 m3/s, while the new orifice was found to succeed the existing orifice to produce 0.03 m3/s, a ten times reduction. Further comparison between the two outlet designs, improvement to the detention capability was obtained, to mention a few parameters: delayed time to peak from 40 minutes by existing orifice to 60 minutes by new orifice and expanded hydrograph base time from 6 hours by existing orifice to 12 hours by the new orifice. The modelling efforts indicated that the smaller orifice to augment the existing orifice would achieve better stormwater control objectives in detaining the urban runoff on site.
High Andean regions present specific challenges that are particularly related to poor visibility at night time and a high incidence of road accidents, which are intensified by the limited availability of public lighting infrastructure. This present study proposes the development of hot-mix asphalt incorporating photoluminescent stones (COLORCEM LUX) as a partial substitution for conventional coarse aggregate, with the purpose to improve road safety during nighttime conditions. Briquettes were designed through the Marshall approach with PEN 60/70 asphalt cement in portions of of 4.5%, 5.0%, 5.5%, and 6.0%, keeping the photoluminescent aggregate content constant at 60.9%. The results obtained indicate that the optimal asphalt cement content is of 5.5% with a Marshall stability with a maximum value of 12.3 kN, as well as a density of 2.35 g/cm³. In terms of luminous performance, the same dosage showed an initial illuminance of 210 lux and still maintained 85 lux after 60 minutes of darkness. Therefore, the outcomes suggest that the controlled incorporation of photoluminescent material does not compromise the mechanical performance of the asphalt mixture and represents a sustainable solution for improving nighttime visibility on access roads serving High Andean communities.
The aim of the research is to assess the technical and economic viability of lime-stabilized soil in creating sub-floor layers for rural homes in the Chilca district, located in Junín (Peru). The study focuses on a geographic area characterized by a high degree of dilapidation due to poverty among families that live there; therefore, it considers the construction of poorly-built houses that lack finishing materials for walls and floors. To establish the technical characteristics of the soil, the author used Modified Proctor Test, unconfined compressive strength and durability tests. The tested lime content included 0%, 4%, 6%, 8% and 10%. A lime content of 6% was found to give the most favourable results when used in a sub-floor layer application while meeting the strength and durability criteria with less lime than that used at other higher levels of addition. A unit price analysis was performed to evaluate the economic feasibility of the subfloor layer constructed with lime-treated soil. This analysis used the unit of an area of 1 m². According to the quantitative analysis findings, the lime-based alternative has an approximate 47.23% less cost than the standard concrete system. Furthermore, lime-based construction has a straightforward installation process, which makes it a practical and viable choice. Using a lime- based product may also limit the use of materials purchased from outside sources because the method encourages using as many locally sourced materials from the area as possible, with the exception of lime, which is the only material added from an outside source.
The deterioration of buildings and infrastructure creates a need for repair materials with adequate mechanical performance and practical applicability. The study focused on evaluate the effect of replacing part of the cement with metakaolin on the fresh-state and mechanical behavior of structural repair mortar. Under this premise, an experimental study was designed with a mix targeting 250 kg/cm², prepared following the ACI method, where the reference mortar was compared with three mixtures in which part of the cement was replaced by 5%, 10%, and 15% metakaolin. The fresh mortar was evaluated through flow, air content, and setting time tests, as well as hardened mortar was also tested for compressive and flexural strength after 7, 14, and 28 days of curing. In general, adding metakaolin reduced flow from 101.48% to 96.37% and increased air content from 3.53% to 5.09% as the dosage increased. Likewise, initial setting time decreased from 344.60 min to 334.70 min and final setting time from 495.40 min to 455.10 min. Regarding mechanical performance, the most favorable response was obtained with 10% metakaolin, reaching a compressive strength of 284.38 kg/cm² and a flexural strength of 41.03 kg/cm² at 28 days. Among the tested mixtures, the 10% metakaolin dosage gave the best overall response, since it kept a good balance between workability and mechanical strength, which may be considered a technically viable alternative for structural repair mortars.
This article presents a systematic review of the Incamisana hydraulic system, addressing three approaches: territorial, functional, and symbolic. Within this framework, it presents the importance of water in the Andean context as an important resource for agriculture, organization, and the practice of rituals. This review was conducted using the PRISMA 2020 methodology, considering studies related to water supply, terraces, channels, fountains, and their symbolic interpretation. The results show that Incamisana was supplied by the Patacancha River through channels. In addition, the terraces fulfilled agricultural functions as well as roles in territorial organization. The system also included underground conduits and drop structures. Thus, the evidence indicates that Incamisana was not only a hydraulic infrastructure for water distribution, but was also associated with landscape integration, rituality, and symbolism. This approach makes it possible to understand the system as a reference for interpreting traditional hydraulic solutions and their relationship with the planning of the Andean territory.
Coastal cities are also experiencing growth in their urban areas, and hence the need to develop alternative and better transportation facilities. The underground metro rail is a viable alternative for the population and is also beneficial for environmental sustainability. However, there are major challenges to be addressed while constructing such facilities. For instance, excavation in such regions demands thorough analysis, and tracks cannot be laid without a thorough understanding of the regions beneath the earth’s surface. This research is focused on Mumbai Metro Line 11 and attempts to assess various environmental factors such as air quality, noise pollution, and changes to the ecosystem and CRZ regulations. Using Geographic Information System technology, the research attempts to integrate genuine environmental data and compare them with other metro rail projects. Based on the secondary indicators examined, the findings suggest that environmental sensitivity tends to be greater in cities that are both coastal and densely populated, although this observation is indicative rather than conclusive and warrants further primary validation. Hence, thorough planning is required to include innovative designs to address geographical constraints and environmental damage.
The ability of MSWIBA as a precursor for geopolymer mixtures amenable to 3D printing is explored in this research. In geopolymer binders, the MSWIBA is utilized in part substitution of fly ash. Investigations are conducted into how the MSWIBA content affects the fresh qualities of printed formulations, particularly setting time, rheological characteristics, and flowability. Additionally, using different amounts of MSWIBA in the mixture, the hardened characteristics of 3D printable MSWIBA geopolymer concrete are assessed. According to the test findings, the MSWIBA content in the mix has enhanced the fresh characteristics of the optimum 3D printed mix. Excellent early age yield stress and apparent viscosity are demonstrated by the optimum mixture with MSWIBA. The incorporation of MSWIBA up to 10 % has enhanced the compressive strength of 3D printable geopolymer concrete samples, whereas higher MSWIBA concentrations has led to a reduction in hardened properties. Lastly, the suggested one-part geopolymer can lessen the carbon emission and embodied energy by up to 11–38% in comparison with OPC concrete.
This study presents the results of a lightweight self-compacting concrete reinforced with sisal fibers. Lightweight aggregates such as expanded clay, pumice, and expanded polystyrene were used as lightweighting materials, replacing up to 30% of the coarse aggregate by volume. Different volumetric fractions and lengths of sisal fibers were added: 0.1%, 0.2%, and 0.3% by volume, and 2.5 cm, 5.0 cm, and 7.5 cm in length. To analyze their influence on workability, the slump test and T500 were used; mechanical behavior was determined through compression and tensile tests at different curing times. The results showed that in the slump test, all mixtures fell within a range of 70 to 80 cm, and the T500 values ranged from 4.3 to 7.2 seconds, including the specimens with sisal fibers. Replacing coarse aggregate with lightweight aggregate and adding sisal fibers negatively affects compressive strength regardless of curing time; however, the presence of the fibers improves tensile strength.
