Journal of Building Materials and Structures

Analyzing energy efficiency strategies and designing and simulation energy efficient systems in buildings

Peyman Afroozeh — 2024-06-30

Green building (also known as green construction or sustainable building) refers to both a structure and the application of processes that are environmentally responsible and resource-efficient throughout a building's life-cycle: from planning to design, construction, operation, maintenance, renovation, and demolition.the past decade has witnessed a rapid increase in the number of studies on GB energy efficiency systems. However, similar studies also indicate that the results of current GB simulations are not yet satisfactory to meet GB objectives. In this study, every particular part of the building construction element was simulated for ensuring energy efficiency.Additionally, a method is introduced that almost satisfies GB objectives by using appropriate modern cost-effective technologies, . This method reduces the initial, running, and maintenance costs of electrical/electronic devices and limits wiring installations, leading to significant energy consumption reduction of about 50%. In this research, renewable energy or green power, that is currently the key solution to tackle the energy crisis ,significantly maximised, hence decreasing the impact of global greenhouse gas emissions.

Intervention Methodology for the Rehabilitation of Damaged Reinforced Concrete Structures

Moulaï Abdellah Bouabdallah — 2024-06-30

The quantity of aging concrete infrastructure deteriorating rapidly is increasing, as are the costs of repairing these structures. The management of interventions on reinforced concrete structures is not always optimal. This is due to the absence of a comprehensive protocol capable of uniformly guiding engineers in their choices regarding the priority and types of work to be carried out on their structures. This lack of decision-making assistance results in interventions that are not always optimal in terms of costs and durability. It is therefore important to establish a diagnostic methodology in order to properly specify the origin of the damage. This will improve the interpretation of defect symptoms and therefore facilitate the subsequent choice of actions and materials required during the intervention on the structure.

This study presents a methodology developed with the aim of standardizing, rationalizing, and integrating the different stages required to achieve optimal and quality interventions into a management tool. Three activities are essential in order to systematize the approach to refurbishment or maintenance of concrete structures: the diagnosis of deterioration, the evaluation of the relevance of interventions, and the selection of appropriate methods and products for refurbishment.

Suitability of crushed sandcrete block (CSB) as a partial replacement for fine aggregate in concrete

Joshua Adoyi Akor — 2024-06-30

The suitability of crushed Sandcrete block (CSB) for use as a partial replacement for fine aggregate in concrete was examined. The physical and mechanical properties of the crushed Sandcrete block and river sand were determined and compared. The specific gravity of the crushed Sandcrete block was found to be 2.58 while that for river sand was 2.66. The concrete with compressive strength of 25N/mm² at 28 days’ hydration period was calculated for the normal mixture as the control. The percentage mix of the fine aggregate was substituted with CSB in different mix proportions of 0:1(0%), 1:3(25%), 1:2(33.3%), 1:1(50%), 2:1(66.7%), 3:1(75%) and 1:0(100%) of crushed Sandcrete block and river sand by weight as fine aggregate. The concrete cubes were cured, and compressive strength tests were carried out at 7, 14, and 28 days. It was observed that the 28-day density and compressive strength for concrete cubes with crushed Sandcrete block alone as fine aggregate (i.e. 100%) were found to be 2420kg/m³ and 22N/mm² respectively compared to the 0:1(0%) proportion which was found to be 2485kg/m³ and 26N/mm² respectively. It was observed that the density and compressive strength reduced with the increasing addition of CSB in all the proportions.

Enhancing the Strength and Durability Behaviour of Concrete Produced with Brown-Loamy Kaolin Clay Polymer

Patrick Zievie — 2024-06-30

Clay is the most utilised natural pozzolana in Ghana, with the red-loamy clay in southern Ghana being the most widely studied. It has been established that clays geographical location presents differences in their optimum calcination temperatures and cement replacement levels. The aim of this study was to investigate the potential use of brown-loamy kaolin clay polymer in northern Ghana as a natural pozzolana. The clay was thermally activated, and it became more pozzolanic reactive at 800^oC. The clay was used to replace cement at 0%, 5%, 10%, 15% and 20% based on the weight of the cement, and denoted as A_o, K₅, K₁₀, K₁₅ and K₂₀ respectively. Concrete cubes of size 150×150×150mm and cylinders of size 150×300mm were cast and cured for 7, 14, 28, and 90 days. The samples were tested for density, compressive strength, split tensile strength, water absorption and sulphate attack. Maximum compressive and split tensile strengths were achieved at the 15% replacement level in all curing durations. Again, there was a significant decrease in water absorption and sulphate attack up to the 15% replacement level. Beyond the 15% and up to the 20%, the decrease was minimal. The increase in strength and decrease in durability properties was significantly high in 90 days compared to 7 days. The study therefore recommends the use of brown-loamy clay up to 15% cement substitution. It use would be advantageous for concrete production in situations where high to medium workability and delays in setting times are required.

Deflection-Based Numerical Evaluation of Steel, Bamboo Fibre, and Carbon Fibre Polymer Reinforced Portal Frame

S.O Odeyemi — 2024-06-30

Reinforced concrete, a flexible building material, enjoys worldwide acceptance. Yet, its environmental footprint, especially regarding steel production, is substantial. The extensive mining of iron ore contributes to global warming, prompting the quest for greener alternatives. Bamboo fibre and carbon fibre were employed in sustainable industrial and construction practices to fulfill tensile requirements in reinforced concrete, effectively managing lateral loads on structural elements. This study aims to compare numerically the deflection resistance of portal frames reinforced with steel, bamboo fibre, and carbon fibre polymers using Abaqus version 6.14. The replacement of steel with carbon fibre within the portal frame exhibited comparable effectiveness to that of utilizing steel, whereas the introduction of bamboo fibre was observed to yield relatively diminished efficacy. However, differences between the results for steel, bamboo fibre, and carbon fibre are minimal, and carbon fibre performs similarly to steel. The maximum lateral movement values are 2.43 mm for steel, 2.68 mm for bamboo fibre, and 2.39 mm for carbon fibre.

Experimental and Numerical Study of Mechanical Properties of Concrete Containing Biochar

S.O Odeyemi — 2024-06-30

The production of cement is responsible for 7% of worldwide CO₂ emissions, leading to environmental threats and harm to ecosystems. Given the significant expenses involved and the necessity for substitutes such as biochar, there is a critical focus on investigating supplementary cementing materials (SCMs) to partially substitute traditional materials. The use of biochar as a concrete admixture is becoming more popular, and it has been investigated as a building material. Biochar is a solid organic residue produced by the pyrolysis of biomass. The experiment aimed to determine the mechanical characteristics of biochar-containing concrete using a concrete grade M20, cube moulds of dimension 100mm x 100mm x 100mm; cylinder moulds of 100mm x 200mm and beam formwork of dimension 150mm x 150mm x 1000mm were used to cast the control concrete sample and concrete containing varying percentages of biochar. Finite element analysis was also carried out using the ABAQUS program, utilizing concrete properties discovered through experimental study. The numerical and experimental study revealed that elevating the proportion of biochar in concrete led to about 17% decrease in compressive strength, 40% reduction in tensile strength, and about 25% reduction in the flexural strength of concrete beams. Both numerical and experimental approaches proved successful in assessing the influence of biochar on concrete.

Investigating the role of insulated tiles as a prospective material for building envelope: thermal performance and energy efficiency

Dr. M. Arif Kamal — 2024-06-30

The residential and commercial sectors account for nearly one-third of the total electricity consumption in India. During the period from 1971 to 2012, the highest increase in electricity consumption was seen in the residential sector with a 9.4% compound annual growth rate, followed by the commercial sector. This has been attributed mainly to the extensive use of air conditioning for thermal comfort in buildings in these two sectors. Building envelope design and construction play an important role in reducing energy consumption in such systems. With the incorporation of thermal insulation materials in combination with other construction materials in a building’s roof and walls, especially in those that are exposed to solar radiation, the energy intensiveness of buildings can be brought down significantly on a long-term basis. Despite the availability of several insulation products in the Indian market, the importance of thermal insulation for buildings for energy efficiency has not been well recognized by building engineers and developers at present. This paper looks into various important aspects related to building insulation materials, right from the principles of building science to the application of materials in buildings. This paper provides a qualitative analysis of insulation materials in the buildings and also provides practice-oriented background information for building designers, architects, site engineers and various other stakeholders in the building construction industry. The paper also evaluates the application of Expanded Polystyrene (EPS) as an insulating material for walls and roofs.