Journal of Building Material Science

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

Etienne Malbila, Luc Bamogo, David Yemboini Kader Toguyeni — Fri, 04 Jul 2025 00:00:00 +0800

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.

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

Mon, 30 Jun 2025 00:00:00 +0800

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.

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

Yi Shi, Shaoliang Wu, Tao Wang, Zhenping Shi — Wed, 09 Jul 2025 00:00:00 +0800

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.