Journal of Building Material Science

Exploring the Effect of a Cement-Based Self-Healing Additive (CS) on the Durability of Cementitious Materials

Yi Shi — 2025-07-09

In order to improve the damage resistance of concrete, a cement-based self-healing additive (abbreviate as CS) was prepared. To investigate the influence of CS on the self-healing performance of cementitious material, X-ray diffraction (XRD) and thermal analysis were used to investigate the effects of different dosages of CS on the hydration process and hydration products of cementitious material. Compressive strength test and load damage self-healing test were used to show the influence of different amounts of CS on the mechanical properties of concrete. The pore structure distribution of cement paste with different dosages of CS was analyzed using mercury intrusion testing method. The results indicated that different dosages of CS had no effect on the types of hydration products of cementitious material. Adding an appropriate amount of CS can effectively improve the micro pore structure of cement-based materials, reduce the proportion of harmful pores in the structure, and decrease the most probable pore diameter. When microcracks are generated in the structure under load, CS can promote the formation of hydration products inside the structure to fill the microcracks, thereby improving the self-healing performance of cement-based materials. This study provides an idea for improving microcracks and enhancing durability of marine concrete structures.

Comparative Analysis of Prediction Model for Non destructive Testing based Compressive Strength Determination

Priyesh Gangele — 2025-07-24

Evaluating the performance of existing concrete structures is essential in civil engineering, with compressive strength serving as an indicator of performance. Non-destructive testing (NDT) techniques are commonly employed due to their cost-effectiveness and the ability to assess structural integrity without causing damage. However, NDT methods often yield less accurate results than destructive testing (DT), which, although highly reliable, is costly and invasive. To address this limitation, recent research has focused on developing predictive models that correlate DT and NDT outcomes using machine learning techniques. This study explores the application of Support Vector Machine (SVM) models, enhanced with optimization techniques, to improve prediction accuracy. Experimental concrete practical samples, ranging from M10 to M40 grade, were prepared and tested at 14 and 28 days of curing, totaling 126 laboratory specimens. Additionally, 231 field samples were collected from a 20-year-old structure to reflect in situ conditions. The performance of SVM was improved using optimization algorithms such as Bayesian Optimization and Genetic Algorithms (GA). Among various kernel functions tested, the Gaussian non-linear kernel proved most effective in modeling the complex relationship between NDT and DT results. The SVM model optimized using Bayesian methods and a Gaussian kernel achieved superior performance, with a high coefficient of determination (R² = 0.9771) and significantly lower error metrics, including Mean Squared Error (MSE), Root Mean Squared Error (RMSE), and Mean Absolute Error (MAE). Bayesian-optimized SVM with a Gaussian kernel offers a highly accurate and practical tool for predicting compressive strength from NDT data, enhancing decision-making in structural assessment.

Photo Catalytic Degradation of Concrete Containing Titanium Dioxide Nanoparticles—A Review

Jegatheeswaran Dhanapal — 2025-06-30

Concrete is one of the key component in the construction field. The importance of concrete is because of its strength and long lasting properties. The incorporation of nano materials in concrete helps to improve the characteristics of conventional concrete. Titanium dioxide (TiO₂) is one such nanomaterial that helps to increase the performance of concrete by enhancing self-cleaning, anti-microbial and anti-bacterial activities. This paper briefly explains about the reaction of titanium dioxide nano particle N-TiO₂on cement materials which in turn changes the mechanical and physical properties of concrete against chemical, climatic changes and abrasion. The review presented here includes the features of titanium dioxide nano particles basically, its dosage in concrete, its impact on concrete on both fresh and hardened properties, photo catalytic effect and anti-microbial. This review explores the photo catalytic degradation of concrete enhanced with N-TiO₂, which presents a promising method for improving the durability and sustainability of concrete structures. The addition of N-TiO₂, recognized for its photo catalytic properties when exposed to UV light, has demonstrated potential in tackling various environmental and structural challenges associated with concrete. The paper provides a detailed analysis of the mechanisms involved in the photo catalytic process, the way N-TiO₂particles aid in breaking down pollutants (including organic compounds, NOx, and CO₂), and its contributions to self-cleaning, antimicrobial functions, and the degradation of harmful pollutants.

Effect of Crystalline Admixture on the Mechanical and Durability Properties of M40 Grade of Concrete

Amit Yadav — 2025-07-21

Crystalline admixtures (CA), also known as permeability reducer admixtures, are used in binder-based materials to improve concrete durability by reducing water permeability depth, increasing compressive strength, and stimulating crack healing. The purpose of this study is to evaluate the potential of crystalline admixtures to enhance the self-healing characteristics and durability attributes of concrete and to contribute to the understanding of their role in the design of long-term efficiency and sustainability. The 28 days specimens of M40 grade concrete were prepared by adding CA and cast as 150 mm cubes, 25×25×285 mm prisms and disks with a diameter of 100 mm and height of 50 mm. All samples were then tested for compressive strength, water permeability, dry shrinkage, sodium sulfate attack test, Rapid Chloride Migration Test (RCMT), and rapid chloride penetration test (RCPT) to study the behavior of incorporating crystalline admixtures in concrete. The conclusion drawn from this study was that the addition of a crystalline admixture of 0.8% resulted in an increase in the compressive strength by 7.98% and a decrease in water penetration depth through the cube by 71.5%, while the dry shrinkage of the specimen incorporated with the crystalline admixture was 65.21% less than that of the specimen without the crystalline admixture. These results substantiate the beneficial role of CA in increasing the durability of concrete through increased strength, lower permeability, and better dimensional stability, thus making crystalline admixtures beneficial for incorporation into high-performance concrete applications.

Beyond Smart Buildings: The Emergence of Intelligent Places through Cutting-Edge Technologies and Material Foundations

Fatah Bakour — 2025-08-18

The rapid emergence of the Internet of Things (IoT), immersive technologies, and spatial devices is transforming architecture by changing the built environment from a passive backdrop to an active participant in user activities. This shift creates complex sociotechnical networks and leads to what we call intelligent places adaptive systems that respond to user behavior, environmental signals, and interactions with architectural components. This study investigates how advanced material foundations and embedded technological objects shape human-building interactions and drive adaptive behaviors in intelligent place systems. We test the hypothesis that integrating virtual reality (VR), augmented reality (AR), and spatial sensors within smart materials creates continuous real-time feedback loops. These loops are expected to enhance user engagement, spatial adaptability, and environmental responsiveness. Employing a qualitative methodology that includes case studies and content analysis, augmented by AI-assisted image analysis, we explore recent trends in smart building design through two projects: the Spatially Intelligent Arts Centre in Geelong, Australia, and the iPortals network of interactive spatial components. The findings indicate that intelligent places are open, dynamic, and continually evolving systems. Technological objects mediate multiloop feedback among users, materials, and building automation, enabling more autonomous, energy-efficient, and responsive environments. This study contributes a conceptual framework for understanding how technological objects and their material Foundations mediate human-building interactions in intelligent places. Future research should consider scalability across different architectural contexts and explore the sociocultural impacts on diverse user groups.

Mechanical Properties of Fiber-Reinforced Self-Compacting Geopolymer Concrete Using Lightweight Aggregate under Microwave Curing Condition

Adam Saab Najim — 2025-08-01

Geopolymer composites are remarkable binding materials due to their sustainability and recyclability. This study investigates the behaviour of Self-Compacting Geopolymer Concrete (SCGC) as a viable alternative to conventional concrete. It examines the effects of adding Lightweight Coarse Aggregate (LWCA) and Steel Fibre (SF) under different curing environments on the fresh and hardened properties of SCGC. Curing was applied using microwave and ambient environments. SF was added at 0%, 0.5%, 1%, and 1.5% of the binder content. Natural coarse aggregate was partially replaced with LWCA by weight at 0%, 33.3%, 66.67%, and 100%. The SCGC mixes were analysed in both fresh and hardened states to evaluate their mechanical properties. Results showed that higher LWCA and SF ratios led to more viscous and cohesive mixes. SCGC specimens under ambient curing exhibited lower compressive, flexural, and tensile strengths compared to those under microwave curing. Microwave-cured samples demonstrated improved performance, with a 38.09% increase in compressive strength for the B6 mix and a 28.02% enhancement in flexural strength. The highest tensile strength (TS) was 4.67 MPa for the B3 mix with 1.5% SF. However, using 66.67% LWCA under microwave curing resulted in a 27.9% reduction in TS. The study recommends using industrial-scale microwave curing and recycled materials, such as steel fibres and LWCA, to produce cost-effective and sustainable SCGC.

Analysis of the Effects of Passive Design for Improving Building’s Hygrothermal Comfort in the Sahelian Climate

Etienne Malbila — 2025-07-04

The present study aims to analyzse alternative passive design solutions for enhancing building energy and hygrothermal efficiency in the Sahelian zone. To achieve this, a model representing a standard single-storey cement-hollow block dwelling building and its relevant parameters was input into EnergyPlus, combined with OpenStudio or SketchUp. Scenarios were then analyzed to evaluate the effects of roof solar reflectivity, wall external insulation, natural ventilation, and their combined options. First, the base case, serving as a reference model, was validated using measured and simulated temperatures by calculating the scientific criteria, such as the NBME and CVRMSE coefficients recommended by the ASHRAE and IPVM standards. Additionally, the numerical simulation was used to compare interior temperatures, discomfort hours, thermal parameters, and the hygrothermal index (IHT) across seven cases studied. The reference model simulation indicated that cement-based hollow blocks are less effective for building envelopes in the Sahelian climate, with 51.48% discomfort hours and an IHT of 1.6, as shown in the Givoni diagram. The results revealed that the wall external insulation was the most effective passive solution, with 56% of comfort hours and an IHT of 0.7, which indicates the expected position of the model within the hygrothermal comfort zone of the Sahelian climate. Combining passive strategies yields the best scenario, resulting in a 28.25% reduction in annual total discomfort hours compared to the base case. These simulations demonstrated the effectiveness of accessible passive design solutions applicable in dwelling construction for the sustainable development of countries in the Sahelian climate.

Surface Temperature Variability in Urban Street Canyons in a Tropical Climate

Letzai Ruiz-Valero — 2025-08-27

Materials used in building envelopes and urban areas contribute significantly to the urban heat island (UHI). In this context, this paper presents a study utilizing infrared thermography (IRT) to assess urban streets and building surface materials in the coastal city of Bayahibe, Dominican Republic. Measurements were conducted in situ in six urban street canyons (Sections A–F) during the warmest and coldest weather conditions. A FLIR T420 thermal camera, FLIR Tools+ software, and the emissivity values of common building materials in Bayahibe were used to determine surface temperatures under sunlit and shaded conditions. The findings show that sunlit surfaces of urban elements generally exhibited higher surface temperatures compared to their shaded counterparts in both warm and cold periods. Metal surfaces displayed the most significant surface temperature differences between sunlit and shaded areas. Additionally, light-colored block walls presented lower surface temperatures than medium and dark-colored ones. This research provides insights into the urban microclimate of Bayahibe under different meteorological conditions. It supports the development of strategies to mitigate the UHI effect and enhance pedestrian thermal comfort in tropical and coastal cities by emphasizing the importance of shading elements and light-colored surfaces. The findings can inform specific interventions and policies for creating more sustainable and climate-resilient urban environments in the Caribbean region.