Journal of Building Materials and Structures

Mechanical Strength and Characteristics of Spent Foundry Admixed Concrete

2025-07-08T20:27:45+00:00

This work is on the experimental study of the effects of spent foundry sand (SFS) and gum Arabic (GA) on concrete properties using a concrete mix proportion of 1: 1.7: 2.6 and a cement content of 357 kg/m³, water-cement (w/c) ratio of 0.5, and a GA dosage of 0.5 %. Six (6) levels of SFS replacements of 10 to 50 % were used and compared with the control concrete containing no SFS with and without 0.5 % GA. Analysis on the mechanical strength was performed using Minitab 18 Software. Also investigated were the hydration products using the XRD and SEM methods of analysis on the crushed concrete samples at the maximum strength (10 %). Some of the results of the investigation are that SFS and GA are compatible and can produce good quality concrete based on the statistical, XRD and SEM analysis. The dominant mineral oxides are CA, Si, Ag, Fe, C, K and Al with a very strong presence of Ca for concrete samples with both SFS and GA. These mineral oxides may have played substantial roles in the modification of the concrete samples.

Durability Performance of Polymer Composite Reinforced with Ceiba pentandra Wood Particles

2025-07-08T20:27:43+00:00

The study investigated the effects of Coptotermes curvignathus termites on the durability and strength properties of wood plastic composites produced from recycled polythene bags and Ceiba pentandra wood particles. The wood particles were proportionately mixed with the polyethylene powder at ratios 40/60, 50/50 and 60/40 (w /w dry basis). The composites were produced using the single screw extruder and compounding method. Some of these composites were exposed to termite attack (Coptotermes curvignathus) attack at a timber graveyard. The composite samples, both unexposed and exposed to termite infestation, were subjected to durability and strength assessment tests. The results revealed composite board densities ranging from 781.0 kg/m3 to 810.6 kg/m3. Strength values ranged from 1087.8 N/mm² to 4320.0 N/mm² for flexural modulus, 43.7 N/mm² to 59.1 N/mm² for flexural strength, and 18.4 N/mm² to 32.6 N/mm² for compressive strength. The wood polyethylene composite made at 50/50 ratio had the lowest values for all properties tested both before and after termite exposure. The wood/polyethylene ratio significantly influence the weight, density, flexural modulus and compressive strength of the composites after termite exposure under a tropical climate. This study concluded that wood polyethylene composite (WPC) reinforced with Ceiba pentandra particles are highly durable. Specifically, WPC produced at a 40/60 wood/plastic ratio is recommended for structural applications in termite-prone areas, as it met the certified standard values of < 3.52 from SNI 01-7207-2006 and ASTM D3345 for graveyard tests.

Evaluating the Effect of Different Sand Types on the Physical, Mechanical, and Durability Properties of Sandcrete Blocks in Ghana

2025-07-08T20:27:43+00:00

The type of sand used in the production of sandcrete blocks greatly influences their strength and durability, which are essential building material qualities in Ghana's construction industry. This study examines how the structural integrity of sandcrete blocks is affected by three different types of sand: pit, river, and sea sand. The mechanical, chemical, and physical characteristics of locally sourced materials were examined in accordance with ASTM guidelines. To create 126 specimens for the experiment, a mixed design with a 1:6, cement-to-fine aggregate ratio and a constant water-to-cement ratio of 0.5 was employed. According to the results, pit sand blocks were the best option for load-bearing structures because they had the highest compressive strength (8.56 N/mm²) and tensile strength (1.69 N/mm²), the lowest abrasion resistance (0.62%), and the water absorption rate (8.02%). On the other hand, blocks made of river sand performed moderately well, exhibiting abrasion resistance of 1.46%, tensile strength of 0.92 N/mm2, and compressive strength of 3.26 N/mm². However, questions about long-term durability are raised by their higher water absorption rate (13.11%). Sea sand-based blocks were the weakest, with a compressive strength of 2.87 N/mm2, a tensile strength of 0.87 N/mm2, abrasion resistance of 1.97%, and the highest water absorption rate (13.42%), The main cause of this weakness is the high levels of sulphate (4.01%) and chloride (4.57%) in sea sand, which jeopardise structural stability. Significant differences between the three types of sand-based blocks were confirmed by statistical analysis using Tukey's HSD test and one-way ANOVA. These results highlight how important strict quality control is when making sandcrete blocks. To improve construction safety and durability, the study suggests giving river and sea sand priority by properly treating them to improve their qualities. This study contributes to the long-term integrity of buildings in Ghana by highlighting the crucial significance of sand selection and offering insightful advice to legislators and construction experts.

Revolutionizing Rigid Pavements Towards Magnetizable Concrete Materials for Charging Electric Vehicles

2025-07-08T20:27:44+00:00

Nowadays, the green economy dictates the urge for finding innovative construction materials to be compatible with the future needs. The growing potential of electric vehicles (EVs) necessitates the transformation towards sustainable and magnetizable concrete pavement. The primary objectives of this work are to determine the optimal materials and mixing proportions to produce high-performance magnetizable mortars for pavement applications. The experimental testing program includes assessing the magnetic properties through the inductance test, the fresh properties using the mini-slump test, the hardened properties through the compressive strength at 3, 7, and 28 days, and the durability through chemical soundness and abrasion resistance. It may be concluded that the magnetic properties of Portland cement mortars can be enhanced through the incorporation of natural magnetite (25% replacement), slag (25% replacement), and scrap iron fillings (70% replacement), and importantly, the addition of enhancers such as magnets, steel mesh, and/or steel bars. These magnetizable mortars can be used for rigid pavement applications since they have a higher abrasion resistance.

Evaluating the effect of different types of dried Automotive Paint Sludge as cement-based composite

2025-07-08T20:27:44+00:00

In this project, we aim to probe four different automotive paint sludge (APS) types; primer coat, phosphate pretreatment coat, base coat and clear coat sludge, as potential additives in cement paste. Specifically, Portland Cement paste was doped with the different APS types which only underwent drying and milling on receipt from a vehicle assembly plant. The mixture was then cured for 7 days, and the resulting concrete was subjected to consistency, setting time, flexural strength and compressive strength tests. On comparison with the control cement paste, the primer coat sludge generally increased the setting time, by as much as 40 % for the final setting time. The compressive strength is negatively affected by the addition of all the different APS. This is somewhat mitigated if clearcoat sludge is used at a 1 wt.%: the difference is less than 10 % to the control. The phosphate pre-treatment coat is the worst performer with a difference of more than 90 %, even at a low APS concentration of 3 wt.% in the cement paste. In contrast, the flexural strength increases with the addition of all but one of the four APS types: phosphate pre-treatment coat. Primer coat sludge is associated with as much as 50 % increase in flexural strength. These results tentatively, show the utility of APS as an additive in cement paste to potentially tailor its properties, thereby decreasing the detrimental environmental impact of disposing of it. APS may also find application in refractory and clay brick manufacture.

Investigating the Effect of Age on Some Mechanical Properties of Coconut Fibre Reinforced Concrete (CFRC)

2025-07-08T20:27:44+00:00

This study explores the long-term effects of aging on the mechanical properties of Coconut Fibre Reinforced Concrete (CFRC) compared to plain concrete (PC). An experimental analysis was conducted on structural-grade concrete mixes, ranging from 20 to 50 N/mm², over curing periods of 28, 60, 120, and 180 days to evaluate compressive strength, split tensile strength, and density. The results indicate that CFRC exhibited a 10–18% reduction in compressive strength compared to PC, depending on the grade and curing duration. In contrast, CFRC's split tensile strength showed a notable 22–35% increase, demonstrating enhanced ductility and crack resistance over time. Additionally, density measurements revealed a 4–9% reduction due to the incorporation of coconut fibres. While CFRC improves sustainability and tensile performance, addressing long-term degradation challenges is crucial for optimal structural applications. These findings provide valuable insights into the viability of CFRC in sustainable construction, informing engineers and policymakers about its long-term performance in tropical environments.

Effect of the transverse reinforcement spacing in nodal zones on the seismic behavior factor of RC frames according to Algerian design code RPA99/version2003

2025-07-08T20:27:42+00:00

The seismic behavior of reinforced concrete (RC) frames is significantly influenced by the confinement provided by transverse reinforcement. This study investigates the effect of transverse reinforcement spacing on the seismic behavior factor (R) of regular RC frames. The objective is to determine which spacing provides an R value in accordance with the Algerian seismic design code (RPA99/version 2003). To evaluate this effect, nonlinear pushover analysis is performed for each configuration. The confined concrete properties are defined using Mander’s model, accounting for variations in compressive strength and strain capacity due to different stirrup spacings. The seismic behavior factor (R) is computed based on the overstrength factor (R_s) and the ductility factor (R_µ), derived from the capacity curves. The results of this study will provide insights into the influence of confinement on ductility and overstrength, allowing for the identification of an optimal stirrup spacing that ensures compliance with the RPA99/version 2003 seismic design code. The findings will help improve reinforcement detailing recommendations for enhanced seismic performance of RC frames.