This paper investigates the effect of replacing different portions of cement by fine oil palm ash (FOPA). A target density of 1000 kg/m3 was used for the foamed concrete mixes. A foamed concrete mix of 1 part binder, 2 parts filler and 0.45 part of water has been used. Cement was replaced at levels of 25, 35, 45, 55 and 65% by weight of binder. The compressive strength, density, water absorption, drying shrinkage and sorptivity were tested at different ages. The mix containing 25% of fine OPA showed enhanced properties in comparison to the control mix at the age of 90 days. The mixed showed higher compressive strength, less water absorption, increased density and lesser sorptivity. However, the same mix showed higher shrinkage readings than that of the control mix.

The limitations of conventional cement mortar as a widely used construction material include low tensile capacity, high permeability, and susceptibility to chemical degradation. The increasing demand for durable and sustainable construction materials has led to increased attention in modifying cementitious materials through nanotechnology. This study investigates the influence of nano-silica (NS) and nano-alumina (NA) on the physical, strength-related, and durability characteristics of cement mortar to determine the optimum nanomaterial type and dosage for performance enhancement. Six mortar mixes, in addition to a reference mix, were designed and prepared by adding 1%, 1.5%, and 2% of the cement weight with NS and NA separately, and were evaluated for flowability, setting time, density, porosity, sorptivity, compressive and flexural strength, rapid chloride penetration, acid resistance, and energy-dispersive X-ray spectroscopy analysis. Both NS and NA slightly reduced flowability but enhanced strength and durability. Incorporation of 1.5% NS yielded the highest 28-day compressive strength (95 MPa), around 12% higher than the control mix, whereas 1% NA resulted in the greatest early-age strength gain. Both nanomaterials enhanced matrix densification, leading to reductions in porosity (up to 22%) and chloride permeability (up to 44%) for NS. In summary, these findings demonstrate that NS outperforms NA in terms of reactivity and durability. Optimal dosages were identified as 1.5% for NS and 1% for NA, providing the best balance of workability, mechanical enhancement, and durability improvements. These results highlight the effectiveness of nanomaterial incorporation as a promising approach to developing high-performance, durable cement mortars suitable for advanced infrastructure applications.

As the global population continues to grow, the cost and environmental challenges associated with traditional construction materials, like cement and river sand, are becoming increasingly significant. The present study examines an alternative environmentally friendly approach to typical building materials. It thus aims to evaluate the feasibility of using foam concrete block waste as a partial replacement for cement to create eco-friendly foamed concrete products. The experimental program involved the deployment of specific machines to prepare finely ground foam concrete waste with a particle size equivalent to that of cement. The replacement levels were 0%, 10%, 20%, and 30% by weight of cement. The effects of the different replacement ratios on the foamed concrete properties were investigated and compared with the control cement-foamed concrete.

The utilization of sugarcane molasses (SCM), a byproduct of sugar refining, offers a promising bio-based alternative to conventional chemical admixtures in cementitious systems. This study investigates the effects of SCM at five dosage levels, 0.25%, 0.50%, 0.75%, 1.00%, and 1.25% by weight of cement, on cement mortar performance across fresh, mechanical, thermal, durability, and density criteria. A comprehensive experimental methodology was employed, including flow table testing, compressive strength (7, 14, and 28 days) and flexural strength measurements, embedded thermal sensors for real-time hydration monitoring, water absorption and chloride ion penetration tests, as well as 28-day density determination. Results revealed clear dose-dependent behavior, with SCM enhancing mortar flowability proportional to dosage, raising the spread diameter from 11.5 cm (control) to 20 cm at 1.25%. At 0.25% SCM, compressive strength (47.5 MPa at 28 days) and flexural strength (~2.9 MPa) were higher than those of the remaining SCM dosages, supported by sustained heat release and positive temperature differentials. However, dosages ≥ 0.5% drastically suppressed hydration kinetics and mechanical performance, with compressive strength falling below 10 MPa. Furthermore, high SCM content led to increased water absorption (up to 10.6%) and chloride permeability (CIP above 5100 C), while bulk density declined from 2250 kg/m³ to 2080 kg/m³ at 1.25% SCM. Statistical validation using one-way ANOVA confirmed that these differences across dosage levels were significant (p < 0.05), underscoring the importance of dosage optimization. This investigation confirms that low-dosage SCM (≤0.25%) can be an effective bio-additive, providing improved workability with negligible compromise in strength and durability. In contrast, higher dosages undermine matrix integrity and performance. Future work is recommended to assess long-term microstructural evolution, field exposure durability, and adaptability across diverse cementitious systems.

Sustainability and construction waste recycling have become crucial topics today in response to the growing environmental challenges and the increasing accumulation of waste. Therefore, it is essential to explore innovative solutions that improve the sustainability of concrete mixes. An effective approach is the use of Lightweight Foamed Concrete (LFC), a revolutionary new material that is considered a viable solution for the reduction of the weight of conventional concrete. This research focuses on the study of the effect of replacing 50% of virgin sand by volume with Recycled Foam Concrete (RFC) waste crushed at four gradation levels with aggregate sizes between 12.5-9.5 mm, 9.5-4.75 mm, 4.75-2.36 mm, and 2.36-1.18 mm, and the effect of adding 0.5% Nano titanium dioxide TiO2 by weight of cement. The water-to-cement and cement-to-aggregate ratio were maintained at 0.45 and 1:1.3, respectively. Nanoparticles are incorporated into Foam Concrete (FC) to enhance its strength, due to their beneficial properties, such as their small particle size and high reactivity. The results conclude on the optimal sizes of RFC with the addition of Nano TiO2 for use in FC mixes that enhance compressive strength and increase carbonation compared to traditional FC mixes.