Concrete mix design and the determination of concrete performance are not merely engineering studies, but also mathematical and statistical endeavors. The study of concrete mechanical properties involves a myriad of factors, including, but not limited to, the amount of each constituent material and its proportion, the type and dosage of chemical additives, and the inclusion of different waste materials. The number of factors and combinations make it difficult, or outright impossible, to formulate an expression of concrete performance through sheer experimentation. Hence, design of experiment has become a part of studies, involving concrete with material addition or replacement. This paper reviewed common design of experimental methods, implemented by past studies, which looked into the analysis of concrete performance. Several analysis methods were employed to optimize data collection and data analysis, such as analysis of variance (ANOVA), regression, Taguchi method, Response Surface Methodology, and Artificial Neural Network. It can be concluded that the use of statistical analysis is helpful for concrete material research, and all the reviewed designs of experimental methods are helpful in simplifying the work and saving time, while providing accurate prediction of concrete mechanical performance.

Foamed concrete is a lightweight construction material that has gained popularity due to its excellent thermal and acoustic insulation properties. Foamed concrete production involves using cement as a binding agent, which results in a high carbon footprint. In response to sustainable development goals (SDG), there has been a growing interest in exploring alternative materials that can replace cement to improve energy efficiency, climate change, resource efficiency, and overall improvement of foamed concrete properties. Several tons of waste generated annually from industry, agriculture, and quarries are dumped into landfills and cause environmental impacts. Nevertheless, the efficiency of this waste presents an interesting question and there is limited knowledge of its use in foamed concrete. Hence, a review study is needed to evaluate the efficiency of different waste materials that could be used to replace cement in foamed concrete production. The objective of this research is to summarize the efficiency of industrial waste (IW) as a pozzolan alternative (PA) for cement replacement in foamed concrete (FC) production. This study aims to evaluate the chemical, physical, and pozzolanic reactions of selected IW and compare them to cement and selected pozzolans to determine the effect of efficient IW on the compressive strength and durability of FC. This research evaluated the efficiency of IW in PA by characterizing their chemical, physical, and pozzolanic reactions. The selected IW was studied and compared to cement and selected pozzolans using XRF and XRD analyses. This study also performed the Frattini test to determine the strength activity index (SAI) of efficient IW. The efficiency of IW in PA was evaluated by comparing the SAI of efficient IW to the minimum 75% required by BS3892. The compressive strength and durability of FC with efficient IW were determined by evaluating the microstructure of the hardened paste of FC using capillary void analysis. The study found that efficient IW, which was classified as siliceous pozzolan type F (ASTMC618-SAF > 70%), rich in amorphous silica and a high Blaine specific area, can replace cement in FC production. The XRF and XRD results showed that the most crystalline components obtained in the IW are SiO₂, Al₂O₃, CaCO₃, and Fe₂O₃. The efficient IW produced more calcium silicate hydrate (CSH) and denser FC, making it stronger, with fewer voids and higher resistance to water absorption. The Frattini test showed that the SAI of efficient IW is greater than the minimum 75% required by BS3892. Incorporating efficient IW as cement replacement in FC produced higher compressive strength and improved the durability of FC. The novelty of this research is in the evaluation of efficient IW as a replacement material for cement in FC production. This study shows that efficient IW can promote the use of waste materials, reduce CO₂ emissions, conserve energy and resources, and improve the properties of FC. This study’s findings can be used by construction industry players to support sustainable development goals by reducing the use of cement and promoting the use of waste materials as a replacement material for cement.

The emission of carbon dioxide by cement manufacturing has caused a negative impact on society and environment such as the greenhouse effect. Disposal of eggshell has created a lot of environmental problems due to its reusability of material is low in many industries. Recent years, researchers have found the value of eggshell due to its high content of calcium carbonate. Consequently, it has encouraged the researchers to incorporate the eggshell as cement replacement for concrete production hence contributing to sustainable development of building materials. This experimental study is aimed to investigate the optimum percentage of eggshell as cement replacement for high strength concrete (HSC) and the effect on HSC were studied in terms of workability, compressive strength and rebound hammer test as well as ultrasonic pulse velocity (UPV). Four types of mix proportion of HSC were prepared namely 0% ESP, 5% ESP, 10% ESP and 15% ESP. Based on the experiment results, the workability of the fresh concrete mixtures decreases as the percentage of eggshell replacement increases. Mix containing 10% eggshell specimen achieved the highest compressive strength of 68.4 MPa at 28 days. Furthermore, the 10% eggshell specimen also achieved the highest value of rebound number of 42.1 and pulse velocity of 6.50km/s at 28 days. Correlation between actual compressive strength and UPV was more reliable and had accurate expression through regression analysis compared to rebound hammer test. Conclusively, the concrete containing 10% eggshell as partial cement replacement exhibits higher compressive strength than control concrete has the potential to be used as construction material.

Image analysis techniques are gaining popularity in the studies of civil engineering materials. However, the current established image analysis methods often require advanced machinery and strict image acquisition procedures which may be challenging in actual construction practices. In this study, we develop a simplified image analysis technique that uses images with only a digital camera and does not have a strict image acquisition regime. Mortar with 10%, 20%, 30%, and 40% pozzolanic material as cement replacement are prepared for the study. The properties of mortar are evaluated with flow table test, compressive strength test, water absorption test, and surface porosity based on the proposed image analysis technique. The experimental results show that mortar specimens with 20% processed spent bleaching earth (PSBE) achieve the highest 28-day compressive strength and lowest water absorption. The quantified image analysis results show accurate representation of mortar quality with 20% PSBE mortar having the lowest porosity. The regression analysis found strong correlations between all experimental data and the compressive strength. Hence, the developed technique is verified to be feasible as supplementary mortar properties for the study of mortar with pozzolanic material.