Journal of Building Material Science

Analysis of the Effect of Nonplanarity on Ground Deformation

2025-09-03T16:34:41+08:00

The movement of interacting faults within the Earth's crust during earthquakes may cause significant structural damage. Large earthquake fault surfaces are often planar or a combination of several planar fault segments. This study analyses the interaction between a non-planar and a planar fault, where the faults are inclined, buried, creeping and strike-slip in nature. The non-planar fault is infinite and formed by two interconnected planar segments, while the planar fault is finite. The present analysis adduces the movement of interacting faults in a composite structure comprised of an elastic layer nested on a visco-elastic substrate of Maxwell medium. The significant effect of various affecting parameters viz. inclination of the faults, velocity of the fault movement, depth of the faults from the free surface, distance between the faults and the non-planarity of the fault has been discussed and also compared. The amount of stress and surface shear strain is restored after the creeping movement. The graphical representation of the effect of non-planarity of the fault on stress-strain accumulation has been established. Analytical solutions are obtained using Laplace transform and Green’s function techniques, supported by numerical simulations. The obtained results provide insights into fault interaction process and have important implications for assessing seismic hazard potential in viscoelastic media. The study of such earthquake fault dynamical models may give some ideas about the nature of stress-strain accumulation or release in the system and help us to observe the mechanism of lithosphere-asthenosphere boundary.

Recent Advances in Predictive Modelling and Material Innovation in Concrete Creep Analysis—A Review

2025-09-17T19:49:47+08:00

Concrete creep, which is characterised by the gradual, time-dependent deformation under sustained loading, remains a critical factor for structural durability, safety and long-term performance. This review synthesises key advancements in creep research, tracing its evolution from early foundational experimental studies and empirical models such as Bažant’s B3 to contemporary materials innovations and emerging computational frameworks. Novel contributions and notable developments include the integration of Finite Element Analysis (FEA), Bayesian optimisation, and fractional calculus, which have significantly improved predictive accuracy under diverse and varying environmental conditions. The study characterised the pivotal role material innovation plays in this evolution and progression, with recent focus on the development of high-performance and sustainable concretes. These advanced materials include Ultra-High-Performance Concrete (UHPC), Recycled Aggregate Concrete (RAC), Ground Granulated Blast-Furnace Slag (GGBFS) modified concrete, Rice Husk Ash (RHA) composites, and nano-modified concretes, all aimed at enhancing creep resistance and sustainability. The study also examines the influence of temperature, humidity, and sustained stress on creep behaviour, highlighting the need for robust multiscale models. Emerging trends, such as artificial intelligence, mesoscopic modelling, and eco-efficient materials, are identified as transformative tools for future research and applications. By bridging historical insights with modern innovations, this work provides a strategic framework for the design of resilient, durable, and sustainable infrastructure systems in the face of evolving performance demands and environmental challenges.

Investigation of Mechanical Properties of High-Performance Steel and Polypropylene Fiber Reinforced Concrete

2025-03-27T17:47:18+08:00

Fiber reinforcement significantly enhances the strength, toughness, and durability of concrete by reducing the propagation of microcracks in the concrete matrix. With the rising demand for high-performance concrete (HPC), this study investigates the mechanical properties of HPC with varying proportions of polypropylene (PP) and steel (ST) fibers. Supplementary cementitious materials (SCMs) toward partial replacement of ordinary Portland cement (OPC) were incorporated to prepare HPC mixes as a ternary composite system using Fly Ash (FA), Silica Fume (SF), and Ground Granulated Blast Furnace Slag (GGBS). Each HPC mix comprised two SCMs, accounting for 20% of the mass fraction of the OPC binder. The study encompassed fiber percentages ranging from 0 to 0.075% PP and 0 to 2% ST, incorporating them into the HPC mixes with gradual increases of 0.025% for PP and 0.5% for ST fiber by mass fraction. All HPC mixes were tested for mechanical properties using compressive and split tensile strength tests. The influence of SCMs on HPC was studied using X-ray diffraction (XRD) for microstructural analyses. It was found that the compressive and split tensile strengths of HPC increased up to an optimal fiber percentage and then decreased. A comparison of the test results of high-performance fiber-reinforced concrete with those of plain HPC revealed significant improvements in compressive and splitting tensile strengths by 26.59% and 57.74%, respectively. Also, the XRD analysis revealed that the composition of the SCMs in HPC was a significant and effective solution for the mechanical properties of the concrete.

Performance of Clay-Based Earth Bricks with Varying Sand Content: A Case Study of Lendi Soil, Douala

2025-10-14T17:04:57+08:00

This study evaluates the influence of sand content on the mechanical behavior and water resistance of compressed earth bricks (CEBs) manufactured from Lendi clay (Douala, Cameroon). Twenty-seven specimens (prismatic and cubic) were produced with three formulations: 0%, 30% and 60% sand substitution by dry mass, compacted at 2.5 MPa and cured for 7, 14 and 28 days. Raw material characterization included particle size distribution, sand equivalent, Atterberg limits, bulk density and Proctor compaction. The clay displayed a liquid limit of 44.07%, plastic limit of 35.23% and plasticity index of 8.84%; optimum moisture content was 15.9% and maximum dry density 1.24 g·cm⁻³. Mechanical testing showed that pure-clay bricks achieved the highest compressive and flexural strengths at all ages (up to ≈ 1.98 MPa and 0.56 MPa respectively). Although the 30% sand mix exhibited marginally higher early compressive strength (7 days), strength decreased substantially by 28 days. Capillary absorption tests revealed an important distinction: while 0% sand bricks exhibited continuous water uptake, they retained cohesion during immersion; conversely, 30% and 60% sand bricks disintegrated into a slurry within seconds of immersion, evidencing severe loss of internal bonding. These findings indicate that, for this highly plastic tropical clay, sand acts primarily as a microstructural diluent that undermines long-term cohesion and durability despite short-term packing benefits. The study underscores the need for locally tailored formulations or stabilizers when designing durable CEBs for humid tropical climates.

Salt Weathering in Anisotropic Calcarenite: Bedding-plane Controls on Sodium Chloride Precipitation Patterns

2025-08-30T15:54:13+08:00

This study investigates the impact of bedding plane orientation on sodium chloride (NaCl) precipitation in a calcarenite stone, subjected to salt weathering cycles. It involves conducting wetting-drying cycles using sodium chloride on two series of specimens sampled parallel and perpendicular to the bedding plane. Capillary imbibition was carried out using saline solutions of two concentrations (15 g/L and 45 g/L). SEM observations show that, across all contaminated samples, halite precipitates mainly on the surface, in the form of efflorescence, while subflorescence remains negligible. The analysis identifies two distinct halite morphologies: (i) cubic crystals of 2 to 10 µm at grain boundaries and (ii) xenomorphic aggregates on pore walls, reflecting that the size and morphology of halite crystals vary according to local nucleation conditions, influenced by the mineralogical composition of the substrates and the degree of supersaturation reached during the cycles. X-ray diffraction analysis revealed significantly higher halite precipitation in samples oriented perpendicular to the sediment bedding (4.53–5.22%) than in those oriented parallel (2.71–4.17%), indicating that bedding plane orientation is a determining factor in weathering processes and the evolution of petrophysical properties. These results demonstrate that capillary transport is intrinsically anisotropic in calcarenite, with bedding orientation controlling both the amount of precipitated salt and the location of crystallizations. This study thus establishes a solid mechanistic framework for predicting salt weathering patterns in stratified heritage stones, and offers concrete perspectives for optimizing conservation strategies in coastal environments.

Carbon Footprint Analysis of Concrete Blocks in Thailand

2025-10-10T21:05:30+08:00

Concrete blocks are widely used for wall construction in Thailand, and reliable Carbon Footprint of Product (CFP) data for these blocks is essential for accurately estimating the embodied carbon of buildings—a crucial consideration in sustainable building design. This research evaluates the CFP of concrete blocks produced by a Thai factory, using a functional unit of one ton. The assessment applies a "Cradle to Gate" approach, covering both raw material acquisition and product manufacturing stages. The study period spans one year, from January 1, 2023, to December 31, 2023. Results show that the CFP for the case study block is 88.508 kgCO₂eq/t, with the raw material acquisition stage responsible for 84.778 kgCO₂eq/t (95.79% of the CFP), and production stage emissions at 3.730 kgCO₂eq/t (4.21% of the CFP). A detailed analysis of greenhouse gas (GHG) emissions reveals several key findings: (1) Portland cement is the primary source, accounting for 80.69% of the CFP; (2) emissions from the transportation of crushed stone and coarse sand are notably high; (3) electricity usage contributes 2.558 kgCO₂eq/t; and (4) broken concrete blocks constitute 12.93% of the mixture volume. This study not only addresses a critical gap in the availability of CFP data for concrete blocks in sustainable building analysis in Thailand, but also identifies key areas where GHG emissions associated with concrete block manufacturing can be reduced. The insights provided here are valuable for concrete block manufacturers across Thailand, especially those with similar production processes, as they work toward lowering the CFP of their products.

Reinforcement of Compressed Earth Bricks Using Locally-Sourced Triumfetta pentandra Fibers: Physical and Mechanical Evaluation

2025-10-10T21:00:36+08:00

This study explores the novel application of Triumfetta pentandra (TP, “Nkui”) fibers, a tropical plant that is abundant yet underutilized in civil engineering, to enhance the performance of compressed earth bricks (CEBs). The main objective is to assess how incorporating these vegetal fibers can improve the mechanical properties of CEBs while maintaining durability. TP fibers were extracted, characterized, and integrated into the soil used for brick specimens. A rigorous experimental protocol was implemented, featuring a unique fiber pre-treatment, the use of a single, homogeneous clayey soil type, and controlled 28-day curing under standard humidity and temperature, which distinguishes this study from previous works. Physical measurements (moisture content, bulk density, water absorption) and mechanical tests (fiber tensile strength, compressive and flexural strength of CEBs) were conducted following French standards. The results indicate that 4 % TP fiber content yields optimal mechanical performance, with compressive strength reaching 6.61 MPa and flexural strength 1.49 MPa at 28 days, compared to 5.16 MPa and 0.51 MPa for unreinforced samples. This demonstrates the potential of TP fibers to reinforce earth-based materials, providing a sustainable, locally sourced, and cost-effective construction solution. However, higher fiber content increases porosity and capillary water absorption (up to 16.75 g at 6 % fibers), highlighting the importance of optimized fiber dosing and potential complementary treatments for long-term durability.

Spalling Resistance and Residual Strength of Hybrid Fibre-Reinforced Reactive Powder Concrete at Elevated Temperatures

2025-11-20T09:21:46+08:00

Reactive Powder Concrete (RPC) is an advanced construction material prized for its superior strength and durability. However, its dense, ultra-low porosity microstructure, while beneficial for mechanical properties, renders it highly susceptible to explosive spalling when exposed to temperatures between 200 °C and 400 °C. This dangerous phenomenon occurs as trapped moisture and air within the RPC’s pores rapidly expand upon heating, generating immense internal vapour pressure that causes sudden surface bursting. This study investigates a synergistic approach by combining steel fibres with low-melting-point polypropylene fibres within fibre-reinforced RPC (FRPC). The principle is that polypropylene fibres melt at approximately 170 °C, creating a network of micro-channels that provide pathways for the release of trapped vapour and air, thereby relieving the internal pressure that causes spalling. To evaluate this, cylindrical specimens (10 cm × 20 cm) were prepared, water-cured for 26 days, and then subjected to steam curing at 95 °C for 4 h. Subsequently, they were exposed to elevated temperatures of 200, 300, and 400 °C for 2 h to simulate fire exposure. The results conclusively show that the hybrid fibre combination effectively prevents explosive spalling. Furthermore, the hybrid FRPC maintained an impressive 80–90% of its original compressive strength post-heating. In stark contrast, FRPC specimens containing only steel fibres suffered severe damage and retained a mere 20–40% of their room-temperature strength. These findings demonstrate that hybrid fibre reinforcement is a highly effective strategy for enhancing the fire resistance of RPC, thereby enabling its safer application for structures prone to elevated temperatures.