Development and characterization of underwater-cast ultra-high-performance geopolymer concrete

Beyond carbon: An integrated LCA–MCDA framework for circularity measurement of ordinary and geopolymer concrete

Sustainable railway concrete sleepers using fibrous rubberized geopolymer concrete

Synergistic effect of polyvinyl alcohol fibers and spindle-like calcium carbonate on the mechanical properties and drying shrinkage of geopolymer concrete

Experimental Study on Fiber-Reinforced Geopolymer Concrete Utilizing Fine Aggregate from Demolition Waste

Inconsistencies in rapid chloride permeability testing of geopolymer concrete: Insights into binder chemistry, pore structure, and test cell configuration

Study on the frost resistance and pore structure evolution of fly ash-coal gangue-based geopolymer concrete

ABSTRACT This study examines the mechanical performance and sustainability potential of bamboo-reinforced geopolymer concrete (GPC) compared with conventional ordinary Portland cement concrete (OPCC). A slag–fly ash-based, air-cured GPC mix (75:25 binder ratio) was activated using an aqueous solution containing calculated amounts of sodium silicate–sodium hydroxide solution and reinforced with treated bamboo (Biduru species). Bamboo culms were air-dried and coated with insecticide, elastomeric paint, and sand to enhance bond and durability. Mechanical tests on compressive, split-tensile, flexural, and bond behaviour were conducted following Indian Standards. GPC achieved higher compressive (39 MPa), split-tensile (2.97 MPa), and flexural (4.72 MPa) strengths than OPCC by 18%, 25%, and 13%, respectively. Treated bamboo-reinforced GPC beams reached 55% of the flexural capacity of steel-reinforced OPCC beams, with a 19% improvement in bond strength and a semi-ductile failure response. These results confirm bamboo’s viability as a renewable, low-carbon reinforcement for non-critical structural applications such as rural housing and sustainable infrastructure. While long-term durability under alkaline and environmental exposures warrants further study, the findings provide experimental evidence supporting the integration of bamboo reinforcement within GPC systems for eco-efficient, resilient construction.

Corrosive marine environments degrade FRP bar-concrete bond through resin softening, interface microcracking, and loss of mechanical interlock, with degradation varying significantly across M20-M60 concrete grades where lower strengths suffer higher relative losses of 15-25%. This review synthesizes 24 experimental studies (2018-2025) on GFRP, BFRP bars with sand-coating, ribbing, fibre-wrapping in normal, seawater sea-sand, and geopolymer concretes tested via pull-out, hinged beam, double-shear methods per IS 456:2000 and ACI 440 provisions. Seawater wet-dry cycles cause maximum 5-10% bond loss after 250 days versus 3-5% immersion; higher grades (C45-C60) boost initial stiffness 50-100% but amplify relative degradation in M20-M30 mixes. Sand-coated surfaces outperform ribbed by 3-8% post-exposure through protected resin interfaces; anchorage shifts failure to tensile rupture achieving 85-95% f_fu utilization. Meta-learning confirms temperature-sulphate cycles-concrete grade as primary drivers. Findings identify optimal grade-surface combinations for coastal structures while highlighting gaps in Indian Zone III-IV validations and 5-year field data.

Fly ash-based geopolymer concrete (FAGC) is a sustainable alternative to Portland cement concrete, offering significant reductions in carbon emissions while maintaining sufficient strength. This study proposes a three-stage framework for developing empirical formulae to accurately and interpretably predict FAGC compressive strength. In the first stage, predictive models were developed using linear regression (LR), deep neural network (DNN), and residual neural network (ResNet) approaches. Among these, the ResNet model achieved the highest predictive accuracy and effectively captured the complex nonlinear relationship between mix components, curing conditions, and compressive strength. In the second stage, global sensitivity analysis identified sodium silicate content, curing time, sodium hydroxide molarity, and water content as the most influential variables. Additionally, the interaction between fine aggregate content and curing temperature was found to have a substantial effect on strength development. In the final stage, an empirical formula was developed based on key variables and their interactions, providing a simple yet reliable tool for practical strength prediction with reduced computational requirements. The proposed framework is expected to bridge the gap between machine-learning prediction and applicability to support mix design optimisation and promote the wider adoption of sustainable geopolymer concrete in construction applications.

Evaluation of the impact of neutral axis depth in flexural performance of reinforced lightweight geopolymer concrete

ABSTRACT Steel fibres, geopolymer binders and recycled aggregates are combined to create Steel Fibre Reinforced Geopolymeric Recycled Aggregate Concrete (SFR–GRAC). The primary challenge with SFR–GRAC is the inconsistent performance of recycled aggregates. To overcome this problem, this paper proposed an analysis of SFR–GRAC Mix Proportions Using Viscoelastic Artificial Neural Networks (SFR–GRAC–VCANN). The primary objective is to investigate SFR–GRAC's constitutive behaviour under uniaxial compression. The viscoelastic constitutive artificial neural networks (VCANN) technique is utilized to forecast the mix proportions of geopolymer concrete. The proposed SFR–GRAC–VCANN approach achieved a high cubic compressive strength of 62 MPa. For a fair comparison, the convolutional neural network (CNN), artificial neural network (ANN) and deep neural network (DNN) models were also implemented using the same dataset and evaluated under identical experimental conditions and pre-processing steps. These baseline models attained compressive strengths of 30, 39 and 40 MPa, respectively. This consistent evaluation framework ensures a reliable comparison of model performance.

Today’s structural floor systems are labour-intensive to install and constrained to prismatic shapes, relying on formwork that leads to material waste and elevated carbon emissions. This research introduces a particlebed 3D-printed, stay-in-place formwork produced from upcycled wood-aggregate. The formwork defines the geometry of the slab and also sequesters biogenic carbon, provides acoustic dampening, and enables complex, performance-optimised geometries. Instead of conventional steel reinforcement, robotically wound natural fibre cords are applied and anchored to dedicated winding points integrated directly into the printed formwork. Combined with cast geopolymer concrete, this approach eliminates the risk of corrosion and significantly reduces embodied carbon. Because the formwork remains in place, no dismantling or disposal is required, resulting in substantial reductions in labour and construction waste. The system’s topology-optimised geometry accommodates embedded utility conduits, removing the need for suspended ceilings and maximising usable space. The result is a lightweight, trade-friendly floor system that is both functionally and environmentally advanced. Its feasibility has been demonstrated at full architectural scale through a 1:1 prototype.

The construction industry plays a vital role in the economic development and overall progress of any country. Construction activities have significant impact on the economy, but their environmental consequences cannot be overlooked. The excessive use of construction materials particularly cement and steel, which are among the most commonly used construction materials, has become a major environmental concern, as these materials are also key sources of carbon emissions. Moreover, the raw materials required for the preparation of cement and Steel are also depleting at a rapid pace. Therefore, it is necessary to conduct research studies to find new alternative materials which can reduce the consumption of cement and steel in the concrete. Fly ash can be used as binding agent in concrete as it has good cementation properties and is abundantly available. To enhance the mechanical performance of geopolymer concrete (GPC), polypropylene fibers (PPFs) were incorporated in varying ratios (0.5% to 1.5% by volume). The samples were prepared to test the mechanical and durability properties of the concrete. Compressive Strength, Flexural Strength, and Split Tensile Strength test was carried out to conclude the mechanical properties of the geopolymer concrete against different percentages of polypropylene Fiber. Acid attack and rapid chloride permeability tests were conducted out to evaluate the durability of the concrete. The research findings depicted that the greatest compressive strength and split tensile strength are obtained at 1% PPFs GPC. The least amount of chloride penetration was demonstrated by GPC, at 1.5% PPFs.

Exploring an intelligent model to predict the compressive strength of UGGBFS based geopolymer concrete

Abstract The construction industry is one of the largest contributors to global carbon emissions, mainly due to the use of Portland cement in concrete, which is widely applied in residential housing. In tropical countries like Indonesia, residential structures typically rely on reinforced concrete systems that result in high embodied carbon throughout the building lifecycle. This study addresses the critical issue of embodied carbon in housing construction by exploring the use of fly ash-based geopolymer concrete as a low-carbon material alternative. The research applies a localized approach by using the Karbonara.id carbon estimator, which follows life cycle assessment stages A1 to A5, to evaluate carbon emissions generated by materials in a three-story residential building located in Jakarta. The study compares two scenarios: one using conventional ready-mix concrete and another replacing it entirely with geopolymer concrete composed of 100% fly ash and alkaline activators (NaOH and Na 2 SiO 3 ). The results indicate a significant reduction of 56.08% in embodied carbon, equivalent to 483.25 kgCO 2 e per cubic meter of concrete. The findings demonstrate the feasibility of applying geopolymer concrete in tropical housing without altering the structural design, offering a practical pathway to reduce carbon emissions at the building scale. The novelty of this study lies in its integration of region-specific emission data and tropical climatic conditions, contributing practical benchmarks for sustainable residential construction. This research supports the global agenda of achieving SDG No. 11 on sustainable cities and communities by promoting material substitution strategies in mid-scale housing projects, especially in coastal and high-density urban areas.

Durability of BFRP bars embedded in geopolymer concrete under hygrothermal exposure and sustained loading

Bamboo reinforced panels with recycled concrete aggregates: A comparative study between cement and geopolymer concrete

Machine learning-driven evaluation of carbon emissions in geopolymer concrete

Fatigue life prediction of Pavement Quality Geopolymer Concrete (PQGC) with recycled geopolymer concrete aggregates using probabilistic approach